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THE   PEOSPECTOE'S 

FIELD-BOOK  AND  GUIDE. 


We  also  publish: 

Jt  Practical  Manual  of  Miner- 
als,  Mines    and   Mining.    By 

Prof.  H.  S.  Osborn,  LL.D.  Illus- 
trated by  171  Engravings.  Second 
Edition.  Revised  and  Enlarged. 
393pp.,  8vo $4.50 

Underground  Treasures:  How 
and  Where  to  Find  Them.    A 

Key  for  the  Ready  Determination  of 
all  the  Useful  Minerals  within  the 
United  States.  By  James  Orton, 
A.  M.  A  new  Edition,  with  Addi- 
tions. Illustrated.  211pp.,  16mo.  $1.50 

Mineralogy      Simplified.        By 

Henry  Erni,  A.  M.,  M.  D.  Third 
Edition,  revised,  re-arranged  and 
with  the  addition  of  entirely  new 
matter,  including  Tables  for  the 
Determination  of  Minerals  by  Chem- 
ical and  Pyrognostic  Characters.  By 
Amos  P.  Brown,  E.  M.,  Ph.  D.,  As- 
sistant Professor  in  charge  of  the 
Department  of  Geology  and  Miner- 
alogy in  the  University  of  Pennsyl- 
vania. 350  pages.  Illustrated  by  96 
engravings,  pocket-book  form,  full 
flexible  morocco,  gilt  edges.   .   $2.50 


THE  PROSPECTOR'S 


FIELD-BOOK   AND   GUIDE 


IN   THE 

SEARCH  FOR  AND  THE  EASY  DETERMINATION  OF 
ORES  AND  OTHER  USEFUL  MINERALS. 


BY 


Prof.  H.  S.  OSBORN,  LL.D, 

AUTHOR  OF  "  THE  METALLURGY  OF  IRON  AND  STEEL,"   "  A  PRACTICAL  MANUAL 
OF  MINERALS,  MINES,  AND  MINING." 


ILLUSTRATED  BY  SIXTY-SIX   ENGRAVINGS. 


SIXTH  EDITION,  THOROUGHLY  REVISED  AND  ENLARGED. 


PHILADELPHIA : 

HENRY  CAREY  BAIRD  &  CO, 

INDUSTRIAL  PUBLISHERS,  BOOKSELLERS  AND  IMPORTERS, 

810  WALNUT  STBEET. 
1903. 


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THE"  1 
CC 

"' 

'  COPY  B. 

Copyright  by 

HENRY  CAREY  BAIR'D  &  CO. 

1903. 


/) 


Printed  by  the 

WICKERSHAM  PRINTING  COMPANY, 

53  and  55  North  Queen  Street, 

Lancaster,  Pa.,  U.  S.  A. 


PREFACE  TO  THE  SIXTH  EDITION. 


The  gratifying  success  of  the  fifth  edition  of 
The  Prospector's  Field-Book  and  Guide,  unmis- 
takably indicating  the  firm  hold  which  it  has  on 
the  confidence  of  Prospectors,  has  rendered  necessary 
the  preparation  of  this,  the  sixth  edition.  In  doing 
this,  the  book  has  been  carefully  revised  through- 
out, and  where  considered  desirable,  it  has  been 
enlarged.  These  revisions  and  amplifications  add 
greatly,  as  it  is  believed,  to  the  value  and  usefulness 
of  the  volume,  and  bring  it  fully  up  to  date. 

The  work  of  revision  has  been  undertaken  by  the 
same  competent  hand  that  so  satisfactorily  edited 
the  second,  third,  fourth  and  fifth  editions.  As 
now  presented  to  the  public,  it  is  felt  to  be  a  com- 
plete and  thoroughly  reliable  guide  and  companion 
to  the  intelligent  and  enterprising  searcher  after 
ores  and  other  useful  minerals,  including  gems  and 
gem-stones ;  the  very  best  that  has  ever  been  pub- 
lished in  any  language.  It  has  been  provided  wTith 
a  thorough  Table  of  Contents  and  an  Index,  ren- 

(v) 


VI  PREFACE    TO    THE    SIXTH  EDITION. 

dering  reference  to  any  subject  in  it  prompt  and 
easy. 

In  conclusion  the  publishers  would  add,  that  they 
confidently  look  for  a  sale  of  this  edition,  the  largest 
in  number  that  they  have  thus  far  issued,  equal  in 
its  rapidity  and  extent  to  that  of  those  which  have 
preceded  it. 

H.  C.  B. 

Philadelphia,  Nov.  2,  1903. 


PUBLISHER'S  PREFACE  TO  THE  SECOND  EDITION. 


The  death  of  Dr.  Osborn,  two  years  ago,  renders 
it  necessary  that  the  Publisher  should  prepare  the 
preface  to  this  revised  edition  of  The  Prospector's 

FIELD-BOOK  AND  GUIDE. 

The  fact  of  a  second  edition  of  this  book  having 
been  called  for  so  soon  after  the  publication  of  the 
large  first  edition,  justifies  the  belief  that  it  has 
supplied  a  public  requirement.  The  task  of  revis- 
ing the  work  has  devolved  upon  thoroughly  com- 
petent hands  ;  and  whilst  it  has  been  aimed,  by  the 
insertion  of  further  information  regarding  the  sub- 
jects treated  in  the  original  edition,  to  make  it  still 
more  acceptable  to  those  for  whom  it  was  prepared, 
a  new  chapter  has  also  been  added  on  Petroleum, 
Ozocerite,  Asphalt  and  Peat,  together  with  a  Glos- 
sary of  Terms  used  in  prospecting,  mining,  miner- 
alogy, geology,  etc. 

While  the  work  of  revision  has  been  done  with 
conscientious  care,  under  the  supervision  of  the 
Publisher,  it  can  hardly  be  hoped  that  it  has  been 
so  well  done  as  if  Dr.  Osborn,  with  his  profound 
knowledge  of  the  subject  treated,  had  been  alive  to 
direct  it  for  himself,  and  in  his  own  manner. 

(vii) 


Vlll       PUBLISHER  S    PREFACE    TO    SECOND    EDITION. 

Henry  Stafford  Osborn  was  born  in  Philadelphia, 
August  17,  1823,  and  died  in  New  York  City,  Feb- 
ruary 2,  1894.  He  was  graduated  at  the  Univer- 
sity of  Pennsylvania  in  1841 ;  went  abroad  in  1843 
or  1844  ;  studied  at  Bonn,  Germany,  and  at  the 
Polytechnic  Institution  of  London.  Before  the 
civil  war  he  held  the  chair  of  Natural  Science  at 
Roanoke  College,  Va.,  and  in  1866  accepted  a  pro- 
fessorship at  Lafayette  College,  Easton,  Pa.  Leav- 
ing Lafayette  in  1870,  he  became,  in  1871,  Professor 
in  Miami  University  at  Oxford,  Ohio.  In  1865  he 
received  from  Lafayette  College  the  degree  of  LL.D. 

In  1869  he  published  "The  Metallurgy  of  Iron 
and  Steel ;  "  in  1888,  "  A  Practical  Manual  of  Min- 
erals, Mines  and  Mining  ;"  in  1892,  the  first  edition 
of  The  Prospector's  Field-Book  and  Guide,  the 
success  of  all  of  which  books  has  been  pronounced. 

Personally,  Dr.  Osborn  was  charming,  full  of  in- 
formation on  a  wide  range  of  subjects,  which  he 
had  studied  thoroughly  ;  enthusiastic,  amiable  and 
just ;  and  the  relations  of  his  publisher  with  him 
during  a  quarter  of  a  century,  will  ever  be  among 
the  brightest  and  best  recollections  of  that  pub- 
lisher's long  career  in  business. 

HENEY  CAEEY  BAIKD. 
Philadelphia,  January  15,  1896. 


PREFACE  TO  THE  FIRST  EDITION. 


In  the  following  pages  we  have  attempted  to 
present  such  a  view  of  the  whole  subject  of  pro- 
specting for  the  useful  minerals  that  any  liberally 
educated  reader  may  fully  comprehend  our  mean- 
ing. We  have  therefore  explained  special  terms 
where  we  have  thought  it  convenient  to  use  them, 
and  where  the  technically  educated  student  would 
not  need  an  explanation. 

It  must  be  understood  that  the  subjects  of  chem- 
istry, mineralogy,  and  metallurgy  are  introduced 
only  for  their  practical  bearing  upon  the  ores  in 
hand,  or  those  sought  for,  and  not  for  theory,  or  the 
philosophy  of  the  operation,  much  as  such  theory 
or  philosophy  would  please  and  instruct.  The 
prospector  must,  therefore,  refer  to  larger  works  if 
he  desire  to  be  instructed  in  the  principles  govern- 
ing the  sciences,  the  teachings  of  which  we  have 
frequently  made  use  of. 

We  would  suggest  to  any  one  intending  to  use 
this  volume  for  practical  work,  to  become  ac- 
quainted with  the  whole  book  before  attempting  to 
use  any  special  part  alone.  The  object  and  con- 
struction   have   made   it    necessary  to   treat   some 

(ix) 


X  PREFACE    TO    THE    FIRST    EDITION. 

special  topics  without  repeating  principles  and 
methods  already  given  in  some  part  of  the  work, 
but  which  bear  some  relation  to  the  topic  under 
immediate  consideration. 

The  Table  of  Contents  and  Index  have  both  been 
carefully  prepared,  and  being  very  fall,  will  make 
reference  to  any  subject  in  the  volume  easy  and 
satisfactory. 

Oxford,  Ohio,  Jan.  5,  1892. 


CONTENTS. 


CHAPTER  I. 

PREPARATORY  INSTRUCTION. 

PAGE 

Disappointment  and  loss  caused  by  lack  of  knowledge  by  pros- 
pectors   1 

Technical  mineralogy,  the  first  study  of  the  prospector;  Defini- 
tion of  a  mineral;  Definition  of  rocks;  Principal  constituents 

of  rocks 2 

Quartz  and  its  varieties;  Feldspar 3 

Most  important  kinds  of  feldspar 4 

Micas;  Most  important  species  of  mica 5 

Amphibole,  often  called  hornblende 7 

Pyroxene,  including  augite 9 

Chlorite 10 

Talc;  Serpentine;  Elementary  composition  of  minerals     .    ■    .  11 
Calculation  of  the  amounts  of  the  elements  going  to  make  up 
any  given  mass;   Definition  of  acids,   bases  and  salts;  Ex- 
amples of  minerals  which  are  salts 12 

Examples  of  silicates;  Colors  of  minerals      13 

Effect  of  the  intermixture  of  coloring  matter 14 

Polychroism;  Phosphorescence ...  15 

Colors  and  forms  under  which  native  metals  may  appear      .    .  16 

Cleavage;  Fracture;  Streak              .    .  17 

Hardness;  Scale  of  hardness 18 

Manner  of  trying  the  hardness  of  a  mineral;   What  may  be 
learned  from  the  test  of  hardness;  Flexibility  and  elasticity; 

Smell ...  19 

Taste;  Malleability;  Ductility 20 

Lustre;  Definition  of  the  various  kinds  of  lustre 21 

Specific  gravity;  Definition  of  the  specific  gravity  of  a  mineral; 

Weight  and  form  of  minerals 22; 

(xi) 


Xll  CONTENTS. 

PAGE 

Importance  of  a  knowledge  of  the  characteristics  of  the  rock 
associated  with  minerals;  Desirability  of  a  general  knowledge 
of  the  manner  in  which  the  geologic  rocks  are  laid  down  23 

Signs  by  which  the  name  of  the  sedimentary  rock  may  be 
determined;  Horizons  of  the  rocks 24 

Movements  of  the  earth's  crust  illustrated  by  a  section  showing 
contorted  strata  due  to  lateral  pressure;  Practical  geology; 
Horizons  sterile  in  ores     ...        25 

Horizons  in  the  United  States  which  abound  in  the  useful 
metals;  Classification  of  rocks;  Definition  of  rocks   ....  26 

General  sameness  in  the  geological  horizons  throughout  the 
world;  Table  showing  the  relations  of  certain  rocks  one  to 
another;  Igneous  rocks 27 

Metamorphic  rock 28 

The  aqueous  rocks;  Sandstone,  illustrated  and  described;  Shale, 
illustrated  and  described;  Granite  29 

Varieties  of  granite 30 

Granite  with  black  mica  and  feldspar  crystals,  with  quartz  as 
chief  base,  illustrated  and  described;  First  indications  of  a 
deposit  possessing  economic  value;  Where  metalliferous  de- 
posits should  be  looked  for 31 

Mode  of  occurrence  of  the  valuable  minerals  and  metal-bearing 
deposits  of  the  earth;  Lodes 32 

Cross  section  of  a  formation  or  horse 33 

Transverse  section  of  solid  quartz  lode  with  casing;  Beds  and 
layers    ... 34 

Irregular  deposits;  Surface  deposits 35 

Selection  of  a  spot  for  starting  actual  prospecting  operations; 
Most  likely  localities  of  auriferous  lodes;  Source  of  gold  in 
the  right-hand  branch  of  a  forked  river .    .      36 

The  right-hand  theory  fully  established  by  practical  experience; 
Spots  upon  which  the  sun  shines  before  noon  richest  in  metal; 
Explanation  of  this  theory;  The  color  of  the  rocks  as  a  guide 
to  the  prospector 37 

Necessity  of  paying  attention  to  the  wash  of  rivers  and  creeks  .      38 

Pilot  stones;  Placers  and  placer  gold £9 

Character  of  placer  diggings;  Forms  of  alluvial  deposits,  illus- 
trated and  described 40 

Estimating  the  value  of  alluvial  claims 41 


CONTENTS.  Xlll 

PAGE 

Indicative  plants;  Vegetation  indicative  of  lead  and  iron      -    .      42 

Vegetation  indicative  of  limestone,  phosphate,  silver,  and  zinc; 
Hints  in  looking  for  deposits  where  superficial  deposits  are 
known  to  occur .    .  43 

Mode  of  occurrence  of  gold  in  Australia  and  California;  Mode 
of  occurrence  of  other  minerals;  Points  to  be  observed  in  ex- 
amining a  lode 44 

Table  showing  the  association  of  ore  in  metalliferous  veins  .    .      45 

CHAPTER  II. 

THE   BLOWPIPE   AND   ITS   USES. 

On  what  chemical  tests  for  minerals  depend;  Illustrations  of  the 

character  of  changes  brought  about  by  chemical  tests  •      46 

Requirements  for  blow-pipe  practice;  Manner  of  preparing  dry 

carbonate  of  soda 47 

Borax  and  other  supplies;  Mode  of  using  the  blow-pipe      ...      48 
Practice  with  the  blow-pipe  by  blowing  upon  a  piece  of  charcoal; 
Colors  of  a  candle  flame ;    Oxidizing   and  reducing   flames 

illustrated  and  described 49 

Roasting;  Illustration  and  practice  in  showing  the  characteristic 
power  of  the  oxidizing  and  reducing  flames;  Mode  of  making 

a  platinum  wire  loop,  illustrated 51 

How  to  make  a  blow-pipe    ...  52 

Principal  means  of  chemically  testing  minerals  before  the  blow- 
pipe; Blow-pipe  experiments;  Recognition  of  the  presence  of 

metals  by  the  color  imparted  to  fused  borax 53 

Table  of  color  indications 54 

Mode  of  testing  with  carbonate  of  soda  on  charcoal 55 

Observations  and  inferences  from  the  above  test 56 

Test  for  sulphur  and  arsenic  and  other  substances ;  Tests  in 
glass  tubes 57 

CHAPTER  III. 

CRYSTALLOGRAPHY. 

The  composition  of  minerals  indicated  by  their  forms ;  Classes 

or  systems  of  crystalline  forms;  Isometric  system 59 

The  cube,  illustrated  and  described;  Variations  of  the  cube  .    .      60 
The  octahedron  and  dodecahedron,  illustrated  and  described; 
Tetragonal  system 61 


XIV  CONTENTS. 

.....  -x-    .  PAGE 

The  prism,  illustrated  and  described;  The  zircon,  illustrated  and 

described;  Hexagonal  system r    .   .  62 

Forms  of  the  hexagonal  system,  illustrated  and  described  ...  63 

Orthorhombic  system    ....        64 

Monoclinic  system;  Triclinic  or  thrice  inclined  system;  Illustra- 
tions of  the  different  systems  of  crystallization 65 

Distinction  between  the  turquois,  lazulite  and  lapis  lazuli  ...  66 

The  topaz  and  its  crystallization 67 

Meteoric  iron ;  Ruby  and  sapphire 68 

Serious  mistake  of  a  Paris  firm  of  jewelers;  Localities  of  gems  .  69 

CHAPTER  IV. 

SURVEYING. 

To  measure  heights  which  are  inaccessible 70 

To  measure  areas,  illustrated  by  examples 72 

To  measure  an  inaccessible  line,  illustrated 75 

The  prism  compass  and  its  use 77 

CHAPTER  V. 

ANALYSES   OF   ORES. 

Wet  Method;  Preliminary  examination;  Detection  of  sulphur, 
arsenic  and  selenium ;  Determination  of  native  gold  or  silver.     79 

Indication  of  copper;  Detection  of  antimony  and  tin;  Determi- 
nation of  manganese,  alumina,  magnesia,  lime,  zinc,  cobalt 
and  nickel 80 

Determination  of  uranium,  titanium  and  mercury;  Detection  of 
carbonates;  Examination  of  sandstone 81 

Qualitative  analysis  of  ores;  Directions  for  the  wet  method  of 
analysis    .    .  .    . 82 

Indications  of  silver,  lead  or  mercury  in  the  assay 84 

Apparatus  for  making  hydrogen  sulphide,  described  and  illus- 
trated; Manner  of  cutting  off  the  bottom  of  a  bottle    ....      85 

The  filtrate;  What  the  precipitate  may  contain 87 

Treatment  of  the  precipitate;  Precipitation  of  chromium  oxide; 
Blow-pipe  test  for  chromium;  Precipitation  of  alumina;  Defi- 
nition of  an  excess 88 

Precipitation  of  manganese,  cobalt  and  nickel      90 

^Establishment  of  the  presence  of  mercury  oxide  and  lead  sul- 
phate       91 


CONTENTS.  XV 

PAGE 

Indications  of  bismuth  and  cadmium,  and  of  copper,  sulphur 

and  gold 92 

Detection  of  platinum  and  arsenic;  Indication  of  antimony  and 

tin 93 

Dry  assay  of  ores;  Crucibles;  Scorifiers;  The  cupel;  The  muffle; 

An  assay  furnace,  illustrated  and  described 94 

Brasquing;  Portable  assay  furnace  for  field  testing 95 

Scales,  weighing,  etc . 96 

Pulverization 97 

Testing  gold  and  silver  ores;  Cupellation 98 

Flax  for  melting  the  ore  in  a  crucible 99 

Process  of  assaying  gold  quartz  100 

Testing  of  lead  ore,  galena;  Testing  of  copper,  tin,  mercury 

and  antimony  ores 101 

Directions  for  making  an  excellent  fire  lute 102 

CHAPTEK  VI. 
Special  Mineralogy, 
gold. 
Importance  of  studying  minerals  from  actual  specimens  ;  Dis- 
tribution of  gold  .  103 

Occurrence  of  gold  in  sea  water;  Chief  sources  of  the  supply  of 
gold  ;  Principal  mode  of  occurrence  of  gold  ;  Composition  of 

native  gold  104 

Mexican  rhodium  gold  ;  Gold  amalgam  ;  Black  gold;  Bismuth 
gold  ;  To  detect  a  content  of  native  gold  in  pyrites  ;  Crystal- 
lization of  gold ;  Gold  crystals,  illustrated  ;  Large  lump  of 
gold  found  at  Forest  Creek,  Victoria,  Australia,  illustrated  .    105 
Physical  properties  of  gold;  Variations  in  the  color  of  gold  .  .    106 
Action  of  gold  under  the  blow-pipe  and  towards  acids    ....    107 

The  bat ea,  described  and  illustrated;  Panning  out 108 

The  cradle  or  rocker,  described  and  illustrated Ill 

The  long  torn,  described  and  illustrated 112 

Sluices  and  their  construction 114 

Hydraulic  mining,  described  and  illustrated  .  ...    115 

Burning  and  drifting  in  the  Forty-Mile  District,  Alaska  .    .    .    118 

Lode  prospecting ...    119 

Directions  for  making  an  amalgamating  assay 120 


XVI  CONTENTS. 

PAGE 

Construction  of  a  retort » 121 

Calculating  the  amount  of  gold  per  ton  an  ordinary  battery 

might  expect  to  save;  Darton's  gold  test 122 

Variation  of  the  above  test;  Other  forms  and  conditions  of  gold.  123 

Placer  gold;  Gold  amalgam 124 

Geology  of  gold;  Occurrence  of  gold  in  quartz;  Original  posi- 
tion of  gold      ...  .    .  125 

Gold  in  granitic  regions,  illustrated  by  section  showing  the  two 
conditions  under  which  gold  is  usually  found  in  rock  and 

drift 126 

Significance  of  an  ironstone  ''blow-out;"  Peculiar  and  seem- 
ingly irregular  deposits  of  gold .        .    .    127 

Origin  of  metamorphic  rocks;  Igneous  rocks  and  their  compo- 
sition; Composition  of  metamorphic  granite     .    .  .    .    129 
Where  the  most  paying  gold  is  found;  Gold  in  combination  .  .    130 
To  separate  gold  in  metallic  sulphides,  for  instance,  iron  pyrites; 

Mode  of  making  fuming  nitric  acid 131 

Another  method  of  detecting  and  separating  the  gold    ....    133 

What  constitutes  profitable  gold  mining ...    134 

Method  of  separating  gold  which  gives  very  accurate  results    .    135 
Description  of  the  Yukon  gold  district,  Alaska;  Dissemination 
of  gold  in  Alaska;  Where  the  profitable  deposits  have  been 

found 136 

Derivation  of  the  gold  of  the  Yukon  district 137 

Extent  of  the  gold-bearing  rocks 138 

Rule  for  ascertaining  the  amount  of  gold  in  a  lump  of  aurifer- 
ous quartz 139 

CHAPTER   VII. 

TELLURIUM,  PLATINUM,  SILVEB. 

Tellurium   minerals;  Tellurium;  Nagyagite,  foliated   or  black 

tellurium 141 

Hessite;  Petzite;  Sylvanite  or  graphic  tellurium 142 

Value  of  tellurides;  Platinum,  its  occurrence  and  properties; 

Platinum  in  California  and  Oregon .    .    143 

Chief  source  of  supply  of  platinum;  Consumption  of  platinum 

in  the  United  States 144 

Sperrylite  and  its  occurrence;  How   to  distinguish  platinum; 

Chemical  test  for  platinum > 145 


CONTENTS.  XV11 

PAGE 

Separation  of  platinum  from  gold  and  other  metals  ;  Prepara- 
tion of  stannous  chloride 146 

Iridium;  Osmium;  Palladium;  Silver,  its  occurrence  and  prop- 
erties ;   Mispickel ;  How  to  distinguish  native  silver  before 

the  blow-pipe 147 

Chemical  test  for  silver 148 

Derivation  of  most  of  the  silver  of  commerce ;  Other  forms  in 

which  silver  is  found;  Silver  glance  or  argentite 149 

Ceragyrite  or  horn  silver  ....  .    .  150 

Stephanite  or  brittle  silver  ore  ;  Red  silver  ore  or  ruby  silver  ; 

Pyrargyrite 151 

Bromic  silver  or  bromyrite  ;  Valuing  silver  ores ;  Geology  of 
silver  ores,  illustrated  by  sections  across  the  Comstock  Lode 
and  surrounding  strata,  east  and  west,  and  north  and  south, 

and  showing  the  mines  and  the  surface 152 

Non-metallic  substances  of  the  Comstock  Lode 153 

Extent  and  value  of  the  Comstock  Lode 155 

Occurrence  of  silver  at  the  Eureka  Mines,  Nevada;  Peculiarity 

of  the  limestone  overlying  the  Eureka  Mines 157 

Geology  of  the  Ruby  Hill  Mines  ;  The  Emma  Mine  ;  General 
geologic  conditions  in  which  silver  ores  are  found 158 

CHAPTER  VIII. 

COPPER. 

Copper,  its  occurrence  and  properties  ;  Manner  of  testing  min- 
erals containing  copper 160 

Natural  combinations  of  copper;  Cuprite,  red  copper  ore  or  red 
copper 161 

Chalcocite,  copper  glance  or  vitreous  copper;  Tetrahedrite  or 
gray  copper  ore 162 

Chalcopyrite  or  copper  pyrites 163 

Peacock  ore  ;  Chrysocolla  or  silicate  of  copper  ;  Black  oxide  of 
copper 164 

Malachite  or  green  carbonate  of  copper ;  Azurite  or  blue  car- 
bonate of  copper;  Variegated  copper  pyrites 165 

Ores  which  furnish  the  bulk  of  the  world's  consumption  of  cop- 
per ;  Geology  of  copper,  illustrated  by  section  of  the  copper 
bed  at  the  Dolly  Hide  Mine,  section  of  strata  in  Lake  Supe- 
rior copper  region,  and  section  of  the  Eagle  Vein,  Lake 
Superior 166 


XV111  CONTENTS. 

PAGE 

Facts  to  be  remembered  to  become  ready  in  the  detection  of 
copper;  Kocks  with  which  copper  is  associated 1G8 

Examination  of  specimens  for  copper  ;  Examination  of  the 
region  in  which  copper  is  supposed  to  occur  .  ....    169 

To  obtain  the  per  cent,  of  copper  in  an  ore 170 

Precautions  to  be  observed  in  the  assay  of  copper 171 

CHAPTER  IX. 

LEAD   AND   TIN. 

Lead,  its  occurrence  and  properties  ;  Galena  ;  Test  for  silver  in 

galena 174 

Order  of  strata  in  the  lead  district  of  Wisconsin,  Illinois  and 
Iowa  ;  Geology  and  form  of  lodes  of  the  galena  ores  illus- 
trated by  lead  lode  in  micaceous  slate  in  mine  near  Middle- 
town,  Conn 175 

Carbonate  of  lead  or  cerussite,  illustrated  by  section  of  strata  in 

California  Gulch,  Colorado  .        • 176 

Sulphate  of  lead  or  anglesite  ;  Phosphate  of  lead  or  pyromor- 

phite;  Chromate  of  lead  or  crocoite 177 

Lead  ochre  or  massicot ;  Lead-antimony  ores ;  Jamesonite  ; 
Zinkenite  ;  The  geology  of  lead  illustrated  by  a  section  of 

galena  limestone 178 

Circulation  of  water  in  lead  veins 179 

Deposit  of  lead  in  a  fissure  of  the  limestone;  Chief  sources  of 

lead  in  the  United  States 180 

Tin;  Assay  of  tin  ore 181 

Cassiterite  or  tin  stone;  Wood  tin;  Toad's  eye  tin;  Stream  tin.   182 

Discovery  of  tin  in  Banca  and  Belliton ....    183 

Tin  pyrites  (sulphide  of  tin);  Occurrence  of  cassiterite  in  the 

United  States 184 

Cassiterite  as  a  type  of  a  strongly  marked  class  of  deposits    .    .     185 

Minerals  most  commonly  associated  with  tin .    186 

Wolframite,  its  properties  and  uses 187 

CHAPTER  X. 

ZINC   AND   IRON. 

Zinc;  Chief  ores  of  zinc;  Smithsonite  or  zinc  carbonate;  Cala- 
mine  188 


CONTENTS.  XIX 

PAGE 

Willemite;  Zincite   or  red   oxide   of  zinc;    Sulphide   of  zinc, 

sphalerite,  or  blende,  or  black  jack    .    ." 189 

Geology  of  zinc,  illustrated  by  section  of  strata  near  Sparta, 

New  Jersey,  zinc  mines 190 

Deposits  of  sulphide  of  zinc  in  Colorado  and  Montana;  Blow- 
pipe  tests  for  zinc;  Iron;  Native  iron;  Chief  ores  of  iron; 

Magnetite,  u  polaric  "  or  loadstone 191 

Franklinite 192 

Specular  ore  or  red  hematite;  Brown  iron  ore  or  brown  hema- 
tite, or  limonite      193 

Spathic  iron  ore  or  siderite;  Black  band  ore 194 

Chromic  iron  or  chromite;  Iron  pyrites     ....  ....    195 

Arsenical  pyrites  or  mispickel;  Geology  of  iron 196 

Geological  horizon  around  the  iron  ores  of  Lake  Superior;  Geo- 
logic regions  in  which  iron  ores  are  found 197 

Section  of  Pilot  Knob,  Missouri;  Use  of  the  magnetic  needle  in 

prospecting  for  iron 198 

W.  H.  Scranton's  report  on  the  subject 199 

Method  of  using  the  compass  in  searching  for  ore 200 

CHAPTER  XI. 

MERCURY,  BISMUTH,  NICKEL,   COBALT  AND  CADMIUM. 

Mercury  or  quicksilver;  Formation  of  amalgams 202 

Cinnabar  or  sulphide  of  mercury;  Metacinnabarite;  Guadalcaza- 

rite;  Native  amalgams 203 

Quicksilver  deposits  of  Almaden,   Spain;    Cinnabar  at  Idria, 

Austria;  Quicksilver-bearing  belt  of  California 204 

Bismuth 205 

Nickel;  Examination  of  nickel  under  the  blow-pipe;  Chief  ores 

of  nickel;  Smaltite;   Nickel   arsenide,   "copper  nickel"    or 

niccolite 206 

Emerald  nickel;  Millerite 207 

Sources  of  nickel  at  Sudbury,  Canada;  Foleyrite;  Whartonite  .  208 
Jack's  tin  or  blueite;  Analysis  of  ores  for  nickel  and  cobalt; 

Separation  of  lead 209 

Separation  of  copper 210 

Precipitation  of  the  iron 211 

Construction  of  a  hydrogen  apparatus 213 

Separation  of  nickel  and  cobalt 215 


XX  CONTENTS. 

PAGE 

Garnierite  and  its  localities;  Cobalt 217 

Smaltite;  Cobaltite;  Erythrite 218 

Linnseite;  Earthy  cobalt,  or  cobalt  wad,  or  asbolite;  Geological 

position  of  cobalt 219 

Cadmium;  Greenockite 220 

CHAPTEK  XII. 

ALUMINIUM,    ANTIMONY,  MANGANESE. 

Aluminium  and  its  distribution;  Minerals  which  serve  as  the 

sources  of  the  metal 221 

Bauxite  and  its  purification  for  the  purpose  of  aluminium  manu- 
facture  222 

Cryolite 223 

Corundum  and  emery 224 

Varieties  of  corundum;  Localities  for  corundum  in  the  United 

States 225 

Chief  European  sources  of  emery;  Test  for  the  quality  of  a 
sample  of  emery  or  corundum;  Antimony  and  the  forms  in 

which  it  occurs 226 

Stibnite  and  its  occurrence  in  the  United  States 227 

Manganese;  Classes  of  manganese  ores;  Wad;  Pyrolusite    .    .    .    228 

Psilomelane;  Manganese  carbonate  or  rhodochrosite 229 

Geological  position  or  manganese 230 

CHAPTEE  XIII. 

VARIOUS   USEFUL,   MINERALS. 

Alum;  Apatite  or  phosphate  of  lime 231 

Coprolites 232 

Arsenic;  Native  arsenic;  Realgar 233 

Orpiment;  Asbestus;  Barytes 234 

Witherite;  Borax .    .    235 

Clays;  Classes  of  soft  clays;  Kaolin,  porcelain  clay,  or  China 

clay 236 

Pottery  or  plastic  clay;  Bole;  Fuller's  earth;  Coal  (mineral)  .  .  237 
Anthracite  (glance  coal,  stone  coal);  Bituminous  coal;   Brown 

coal  or  lignite;  Jet;  Dolomite 238 

Feldspar,  orthoclase;   Adularia;  Moonstone;  Sunstone;  Aven- 

turine;  Amazon  stone 239 


CONTENTS.  XXI 

PAGE 

Flint;  Hornstone  or  chert;  Fluorspar,  fluorite;  Graphite,  plum- 
bago, or  black  lead 240 

United  States  localities  for  graphite 241 

Mode  of  testing  the  purity  of  graphite;  Gypsum 242 

Alabaster;  Satin  spar;  Plaster  of  Paris;  Infusorial  earth;  Litho- 
graphic limestone 243 

Meerschaum  or  sepiolite;  Micas 244 

Biotite  or  black  mica;  Muscovite  or  potash  mica;  Molybdenum.  245 

Nitre  or  saltpetre;  Rock  salt 246 

Occurrence  of  salt  deposits;  Deposit  of  rock  salt  in  Petite  Anse 

Island,  Louisiana 247 

Slate;  Sulphur         249 

Method  of  estimating  the  sulphur  available  to  tha  acid  maker 

in  a  sample  of  pyrites;  Talc,  soapstone,  or  steatite 250 

CHAPTER  XIV. 

PETROLEUM,    OZOCERITE,    ASPHALT,    PEAT. 

Occurrence  of  crude  petroleum;  Outfit  and  best  time  of  the  year 
for  prospecting 252 

Examination  of  the  iridescent  film  on  the  surface  of  water;  In- 
dication of  an  outcrop  of  oil     .    .    .  253 

Tracing  the  source  of  the  oil;  The  water  test;  Fresh  fracture  of 
oil-bearing  sandstone 254 

Color  of  traces  of  oil  upon  the  surface  of  water  in  cooler  weather  ; 
Iridescent  films  in  swampy  puddles 255 

Salses  (mud  volcanoes)  and  exhalation  of  natural  gas  as  an  in- 
dication of  petroleum;  Occurrence  of  oil  in  definite  geological 
horizons        256 

Occurrence  of  oil  in  beds  or  in  veins;  Tracing  a  thick  seam  or 
stratum  of  oil-bearing  sandstone;  Outcrops  in  a  large  mass  of 
sandstone.  257 

Data  to  be  made  in  the  sketch-map  when  promising  out-crops 
of  oil  have  been  found,  illustrated  ....     258 

Vein-like  occurrence  of  oil,  described  and  illustrated     ....    259 

Occurrence  of  oil  in  a  maze  of  smaller  and  larger  fissures  .    .    .    260 

Quality  of  the  oil;  Ozocerite  and  its  occurrence;  Ozocerite  de- 
posit in  East  Galicia,  described  and  illustrated 261 

Mineral  resins  closely  allied  to  ozocerite  262 

Retinite;  Elaterite;  Pyropissite;  Properties  of  ozocerite    .    .    .    263 


XX11  CONTENTS. 

PAGE 

Native  asphalt  or  bitumen;  Most  remarkable  deposits  of  as- 
phalt; Asphalt  in  California  and  other  portions  of  the  United 
States 264 

Peat 265 

CHAPTER   XV. 

GEMS  AND   PRECIOUS  STONES. 

Occurrence  of  gems  and  precious  stones  in  the  United  States; 

Comparatively  little  value  of  many  gems      266 

Occurrence  of  diamonds  and  gold  in  the  same  alluvial  deposit.  267 
Use  of  the  dichroiscope  in  distinguishing  gems    .    .  .    .    268 

Diamond;  Occurrence  of  diamonds  in  India,  and  in  Borneo  .  •    270 
Diamonds  in   Brazil;  Carbonado  or  black  diamond;  Minerals 

associated  with  the  diamond  in  South  Africa 271 

The  diamond-bearing  ground  at  the  Kimberley  Mine,  South 
Africa;  Occurrence  of  the  diamond  in  the  Ural,  Australia, 

New  Zealand,  and  in  the  United  States 272 

Natural  surface  of  the  diamond ;  Color  of  the  diamond  ....     273 

Properties  of  the  diamond 274 

On  what  the  value  of  the  diamond  depends 275 

Some  of  the  largest  diamonds,  illustrated  ;  The  Koh-i-noor ; 
The  Orloff;  The  Grand  Duke  of  Tuscany  or  Florentine;  The 

Pitt  or  Regent;  Sapphire .    .    276 

Ruby  and  its  varieties ...    277 

Topaz  and  localities  for  it  in  the  United  States 278 

Beryl  or  emerald;  Phenacite 279 

Zircon;  Garnet  and  localities  for  it  in  the  United  States    .    .    .    280 

Tourmaline 281 

Epidote;  Opal  and  its  varieties 282 

Turquois,  and  localities  for  it  in  the  United  States 283 

Agate  and  its  varieties 284 

Chalcedony;  Chrysoprase;  Carnelian  and  sard;  Jasper;  Blood- 
stone or  heliotrope .    285 

Rock  crystal ;  Amethyst ;  Rose  quartz;  Smoky  quartz;  Yellow 

or  citron  quartz,  or  false  topaz .     286 

Onyx  and  sardonyx;  Cat's  eye;  List  of  gem-stones  compiled  by 

Mr.  George  F.  Kunz 287 

List  of  gem-stones  known  to  occur  in  the  United  States  ....    288 


CONTENTS.  XX111 

PAGE 

List  of  species  and  varieties  found  in  the  United  States,  but  not 
met  with  in  gem  form ;  List  of  species  and  varieties  not  yet 
identified  in  any  form  in  the  United  States  ;  List  of  gem- 
stones  occurring  only  in  the  United  States 289 

Table  of  characteristics  of  gems 290 

APPENDIX. 

Prospecting  by  means  of  electricity 293 

Weights  and  measures  ;  Basis  of  British  weights  and  measures.  295 
Weights  and  measures  of  various  nations;  English  length ;  Par- 
ticular measures  of  length;  Surface  measure 296 

Surface  measure  in  feet;  Solid  measure;  Troy  weight;  Avoirdu- 
pois weight;  Weight  by  specific  gravity;  Method  of  finding 

the  weight  of  masses  without  the  use  of  scales 297 

How  to  find  the  specific  gravity 299 

Special  weights,  etc >    .    .    300 

French  measure;  Length;  Surface;  Solid  measure;  Weight    .    .    301 
Specific  gravity  of  metals,  ores,  rocks,  etc. ;  Ores  associated  with 

gold  and  silver;  Other  ores 302 

Specific  gravity  of  minerals  of  common  occurrence;  Average  in 

cubic  feet  of  a  ton  weight  of  various  materials 303 

Assay  of  gold  by  the  touchstone  . 304 

Estimation  of  gold  in  alloys         305 

Standard  value  of  gold  in  different  countries;  Power  for  mills  .    307 

Boring;  Diamond  drill 308 

The  chemical  elements,  their  symbols,  equivalents  and  specific 

gravities £09 

To  find  the  proportional  parts  by  weight  of  the  elements  of  any 
substance  whose  chemical  formula  is  known;  Common  names 

of  chemical  substances 311 

Prospectors'  pointers 313 

Glossary  of  terms  used  in  connection  with  prospecting,  mining, 

mineralogy,  geology,  etc  . 315 

Index 3£5 


THE 

PROSPECTOR'S  FIELD-BOOK  AND  GUIDE. 


CHAPTER  I. 

PREPARATORY   INSTRUCTION. 

It  is  well-known  that  much  disappointment  and 
loss  accrue  through  lack  of  knowledge  by  prospec- 
tors, who,  with  all  their  enterprise  and  energy,  are 
often  ignorant,  not  only  of  the  probable  locality, 
mode  of  occurrence  and  widely  differing  appearance 
of  the  various  valuable  minerals,  but  also  of  the 
best  means  of  locating  and  testing  the  ores  when 
found.  It  is  a  well-established  fact  that  the  major- 
ity of  the  best  mineral  finds  have  been  made  by  the 
purest  accident,  often  by  men  who  had  no  mining 
knowledge  whatever,  and  that  many  valuable  dis- 
coveries have  been  delayed,  or,  when  made,  aband- 
oned as  not  payable  from  the  same  cause — ignor- 
ance of  the  rudiments  of  mineralogy  and  mining. 
Hence  in  preparation  for  skilled  work,  the  prospec- 
tor should  have  become  thoroughly  acquainted  with 
the  forms  under  whicli\useful  minerals  and  metals 
appear, 


This  should  be  his  very  first  study.  .  It  may  be 
called  the  study  of 

TECHNICAL    MINERALOGY. 

By  a  mineral  is  meant  any  chemically  homogene- 
ous substance  which  neither  forms,  nor  retains  any 
traces  of  having  formed,  part  of  an  organized  being, 
and  which  has  not  been  produced  by  the  applica- 
tion of  physical  forces  by  man.  The  properties  of 
minerals  are  numerous.  Some,  such  as  the  form, 
bulk,  hardness,  color,  etc.,  are  readily  perceived ; 
while  others  such  as  the  chemical  nature,  crystalline 
structure,  behavior  towards  light  and  heat,  are  not 
so  apparent,  and  can  only  be  determined  by  means 
of  a  systematic  investigation.  The  value  of  these 
properties  in  affording  distinguishing  characters 
differs  greatly,  but  the  most  important  are  chemical 
composition,  crystalline  form,  and  density. 

When  two  or  more  minerals  occur  together  and 
form  large  masses,  they  constitute  rocks. 

The  minerals  which  are  the  principal  constituents 
of  rocks  are  the  following  : 

1.  Those  containing  silica:  as  quartz;  the  feld- 
spars ;  the  micas ;  hornblende  ;  pyroxene ;  talc ; 
serpentine ;  chlorite. 

2.  Carbonates :  as  carbonate  of  lime  or  calcite ; 
carbonate  of  lime  and  magnesia  or  dolomite. 

3.  Sulphates:  as  sulphate  of  lime  or  gypsum. 
The  special  characteristics  of  these,  and  of  other 

less  frequent  mineral  constituents  may  be  learned 
from  a  text  book  on  mineralogy.     The  following  are 


PREPARATORY    INSTRUCTION.  6 

the  prominent  characters  of  the  most  common  kinds 
concerning  the  prospector  : 

Quartz.  Occurs  in  crystals  ;  also  massive  with 
a  glassy  lustre.  It  is  too  hard  to  be  scratched  with 
a  knife.  It  varies  in  color  from  white  or  colorless 
to  black,  and  in  transparency,  from  transparent 
quartz  to  opaque.  It  has  no  cleavage,  that  is,  it 
breaks  as  easily  in  one  direction  as  another  like 
glass. 

There  are  many  varieties  of  quartz,  of  which  may 
be  mentioned  :  Limpid  quartz,  clear  and  colorless ; 
amethyst,  violet  crystals ;  agate,  presenting  various 
colors  arranged  in  parallel  bands,  straight,  curved, 
or  zigzag ;  chalcedony,  transparent  or  translucent, 
and  varying  in  color  from  white  to  gray,  blue, 
brown  and  other  shades ;  flint,  massive,  dark  and 
dull  color,  edges  translucent ;  hornstone,  resembles 
flint,  but  differs  from  it  in  being  more  brittle,  in 
breaking  with  a  splintery,  uneven  fracture,  and  in 
not  being  so  hard  as  quartz  ;  basanite,  Lydian  stone, 
or  touchstone,  velvety  black,  more  opaque  than  horn- 
stone.     It  is  used  for  trying  the  purity  of  gold. 

Opal  is  also  a  form  of  silica. 

Feldspar.  This  name  is  given  to  a  group  of 
minerals  which  are  inferior  to  quartz  only  as  a  con- 
stituent of  rocks.  They  have  a  lustre  nearly  like 
quartz,  but  often  somewhat  pearly  on  smooth  faces, 
are  very  nearly  as  hard  as  quartz,  with  about  the 
same  specific  gravity  (2.4  to  2.6);  and  in  general 
have  light  colors,  mostly  white  or  flesh-colored, 
though  occasionally  dark  grey,  brownish  or  green. 


They  differ  from  quartz  in  having  a  perfect  cleav- 
age in  one  direction,  yielding  under  the  hammer  a 
smooth  lustrous  surface  and  another  nearly  as  per- 
fect in  a  second  direction  inclined  84°  to  90°  to  the 
first ;  also  in  being  fusible  before  the  blowpipe, 
though  not  easily  so  ;  also  in  composition,  the  feld- 
spars consisting  of  silica  combined  with  alumina 
and  an  alkali — this  alkali  being  either  potash,  soda, 
or  lime,  or  two  or  all  of  them  combined.  Included 
in  this  group  are  a  number  of  distinct  kinds  or 
species.  These  species  differ  in  the  proportion  of 
silica  (the  acid)  to  the  other  ingredients  (bases),  and 
in  the  particular  alkali  (potash,  soda,  or  lime)  pre- 
dominating. 

The  most  important  kinds  are : 

Orthoclase,  or  common  feldspar,  a  potash  feldspar. 
The  cleavages  make  a  right  angle  with  one  another, 
whence  the  name,  signifying  cleaving  at  a  right 
angle. 

In  the  following  kinds  the  cleavages  make  a  right 
angle  with  one  another  of  84°  to  87°  and  hence 
they  are  sometimes  called  anorthic  feldspars  or 
plagioclastic  feldspars. 

Albite,  a  soda  feldspar,  colorless  and  transparent, 
or  translucent,  and  various  shades  of  red,  yellow, 
green  and  gray. 

Oligoclase,  a  soda-lime,  the  soda  predominating. 
Color,  generally  whitish  or  grayish  with  shades  of 
green  and  yellow. 

Labradorite,  a  lime  soda,  often  iridescent.  Color, 
usually  ash  or  greenish  gray,  but  frequently  various 


PREPARATORY    INSTRUCTION.  5 

shades  of  green,  yellow,  and  red,  and  sometimes  the 
smaller  crystals  are  colorless. 

Anorthite,  a  lime  feldspar,  transparent  and  color- 
less, or  translucent  and  greyish  or  reddish. 

Feldspars  are  essentially  constituents  of  volcanic 
and  crystalline  igneous  rocks,  orthoclase  being 
typical  of  granite,  syenite,  gneiss  and  trachyte, 
usually  in  association  with  quartz. 

Labradorite  is  the  feldspar  of  basalts  and  doler- 
ites  in  microscopic  crystals,  and  it  also  forms 
enormous  rock  masses  in  Labrador.  Oligoclase  may 
be  associated  with  orthoclase  in  granite,  and  is  the 
feldspathic  constituent  of  diorite  and  diabase.  An- 
desite  is  the  feldspar  of  the  trachytes  of  the  Andes. 
Albite  is  chiefly  found  in  crystalline  schists  and  also 
in  granite  veins.  Anorthite  is  best  developed  in 
the  crystalline  limestone  blocks  of  Vesuvius,  and 
also  occurs  in  some  basalts. 

Micas.  This  embraces  a  group  of  minerals 
whose  most  marked  common  feature  is  a  highly 
laminated  structure,  and  they  admit  of  being  split 
into  leaves  even  thinner  than  paper.  They  are 
colorless  to  brown,  green,  reddish  and  black,  and 
occur  either  in  small  scales  disseminated  throughout 
rocks — as  in  granite — or  in  large  plates.  The 
micas  are  silicates  of  alumina  with  either  potash, 
magnesia  or  iron  and  some  other  ingredients. 

The  most  important  species  of  mica  are : 

Muscovite.  This  is  the  common  mica  which  in 
the  form  of  clear  or  slightly  smoky  colored  plates  is 
used  in  the  doors  of  stoves  and  lanterns.     In  Russia 


6  prospector's  field-book  and  guide. 

it  was  used  for  the  windows  of  houses  and  this  gave 
the  name  to  the  mineral  of  Muscovy  glass,  whence 
the  mineralogical  name  of  muscovite. 

Muscovite  is  a  potash  mica  usually  occurring  in 
rhombic  or  six-sided  tabular  crystals.  In  many 
rocks  the  crystals  are  but  poorly  developed  or  only 
represented  by  irregularly  shaped  scales ;  cleavage 
basal  and  very  perfect ;  color,  mostly  silvery  white, 
seldom,  but  occasionally,  dark  brown  or  black.  Be- 
fore the  blowpipe  it  whitens  and  fuses  on  thin  edges 
to  a  grey  or  yellow  glass.  Muscovite  is  not  decom- 
posed by  sulphuric  or  hydrochloric  acid. 

Lepidolite.  Some  of  the  potash  micas  contain 
lithia,  and  these  are  generally  distinguished  as 
lithia  mica.  Lepidolite  is  a  lithia  mica,  the  potash 
of  muscovite  being  partially  replaced  by  lithia.  It 
is  frequently  a  substitute  for  muscovite  in  granites. 
It  usually  occurs  in  fine  scaly  or  granular  aggre- 
gates rather  than  definite  crystals.  The  color  is 
generally  violet,  rose-red,  or  violet  grey,  and  occa- 
sionally white.  Lepidolite  colors  the  flame  of  the 
blowpipe  purple  red.  After  fusion  before  the  blow- 
pipe it  is  completely  decomposed  by  acids,  but 
otherwise  it  is  only  imperfectly  soluble. 

Phlogopite,  a  magnesia  mica  of  light  brown  or 
copper-red  and  sometimes  white  color.  It  is  com- 
mon in  limestone  or  in  serpentine  rocks  and  in 
dolomites. 

Biotite.  This  includes  most  of  the  magnesia-iron 
mica.  Color,  black  or  dark  green.  Very  thin 
laminae  appear  brown,  greenish  or  red  by  trans- 


PREPARATORY    INSTRUCTION.  7 

mitted  light.  Lustre  pearly,  hardness  2.5  to  3, 
specific  gravity  2.7  to  3.1.  The  basal  cleavage  is 
highly  perfect  and  the  laminae  are  flexible  and 
elastic  as  in  other  members  of  the  mica  group.  It 
is  only  slightly  acted  upon  by  hydrochloric  acid, 
but  is  decomposed  by  sulphuric  acid,  leaving  a 
residue  of  glistening  scales  of  silica.  Biotite  is  the 
second  most  important  mica. 

Lepidomelane  is  an  iron-potash  mica.  It  occurs 
in  small  six-sided  tabular  crystals,  or  in  aggregations 
of  minute  scales.  Color,  black ;  lustre  adamantine 
or  somewhat  vitreous.  Easily  decomposed  by 
hydrochloric  acid,  leaving  a  fine  scaly  residue  of 
silica. 

Lepidolite  or  lithia  mica  resembles  muscovite  in 
crystalline  form  and  many  of  its  physical  properties* 
Its  color  is  white,  yellowish  or  rose  red,  the  last  be- 
ing very  prevalent.  It  fuses  before  the  blowpipe 
more  readily  than  muscovite,  and  is  decomposed  by 
hydrochloric  and  sulphuric  acids  but  not  so  readily 
as  the  magnesian  micas.  Lepidolite  is  most  com- 
monly met  with  in  metalliferous  veins,  especially 
those  containing  tin,  and  is  nearly  always  associated 
with  other  minerals  which  contain  fluorine,  such  as 
fluorspar,  topaz,  tourmaline,  and  the  emerald ;  it  is 
also  frequent  in  many  kinds  of  granite. 

Amphibole,  often  called  Hornblende.  The 
most  common  kind  is  an  iron-bearing  variety,  in 
black  cleavable  grains  or  oblong  black  prisms  cleav- 
ing longitudinally  in  two  directions  inclined  to  one 
another  124°  3 0'.     It  occurs  also  in  distinct  prisms 


8 

of  this  angle,  and  of  all  colors  from  black  to  green 
and  white. 

Actinolite  is  the  name  applied  to  the  green  variety, 
and  besides  lime  and  magnesia,  contains  also  iron. 
It  occurs  often  in  fibrous  or  columnar  masses,  some- 
times with  a  radiated  structure. 

Tremolite  is  a  lime-magnesia  hornblende.  The 
pure  crystals  are  white,  but  the  impure  ones  are 
yellowish  or  greenish  gray  owing  to  the  presence  of 
protoxide  of  iron.  There  are  several  varieties  of 
tremolite.     Thus  the  substance  known  as 

Asbestus  *  is  in  most  cases  tremolite  containing  a 
little  water.  It  generally  occurs  in  fine  fibres  which 
may  be  isolated  or  packed  closely  together  with 
their  principal  axes  parallel. 

Mountain  leather  is  a  similar  mineral,  but  the 
fibres  are  finer,  closer  and  intermixed. 

Mountain  cork  is  a  spongy,  elastic  asbestus,  with 
the  fibres  interlaced  together. 

Mountain  wood  is  like  the  last,  but  denser,  far  less 
elastic  and  capable  of  taking  a  high  polish. 

Nephrite  or  oriental  jade  is  a  compact  variety 
much  used  by  the  Chinese  as  a  figure  stone.  The 
color  is  sometimes  light  green  as  in  the  white  jade  ; 
and  olive  green,  as  in  the  green  jade.  It  has  an  un- 
even, fine-grained  fracture,  and  a  greasy  lustre. 

Tremolite  is  found  in  many  places,  but  nearly 

*Most  of  the  asbestus  mined  for  use  in  the  arts  is  a  fibrous 
variety  of  serpentine,  and  is  easily  distinguished  because  it  con- 
tains about  14  per  cent,  of  water. 


PREPARATORY    INSTRUCTION.  \) 

always  in  the  older  dolomites  and  saccharoidal 
limestones. 

Pyroxene,  including  augite.  Like  hornblende 
in  most  of  its  characters,  its  varieties  of  colors  and 
its  chemical  composition.  But  the  crystals  instead 
of  being  prisms  of  124°  30',  are  prisms  of  87°  5'. 
Black  and  dark  green  pyroxene  in  short  crystals  is 
called  augite.  It  is  an  iron-bearing  kind  and  is 
common  in  igneous  rocks. 

The  minerals  of  the  amphibole  group  closely  re- 
semble pyroxene  in  chemical  composition,  while 
they  also  crystallize  in  the  same  system.  They 
differ,  however,  in  the  angular  measurements  of  the 
oblique  rhombic  prism,  which,  as  already  shown, 
in  hornblende  is  124°  30',  and  in  augite  87°  5'  to 
92°  55'. 

They  are  all  bisilicates  of  protoxides  and  sesqui- 
oxides,  the  former  being  lime,  magnesia,  soda, 
potash,  and  the  protoxides  of  iron  and  manganese, 
while  the  latter  are  represented  by  alumina  and  the 
protoxides  of  iron  and  manganese. 

Crystals  of  amphibole  differ  from  those  of  pyrox- 
ene, not  merely  in  the  angular  measurements  of 
their  oblique  rhombic  prisms,  but  also  in  the 
angles  at  which  their  cleavage  planes  intersect. 
This  circumstance  is  of  considerable  value  to  the 
mineralogist,  since  it  is  often  difficult  or  impossible 
to  measure  the  angles  of  the  actual  crystallographic 
faces,  but  is  generally  possible  to  measure  the  angles 
of  cleavage.  The  crystals  of  minerals  belonging  to 
the  amphibole  group  usually  exhibit  a  fine  longi- 
tudinal striation. 


10        prospector's  field-book  and  guide. 

Color  affords  no  safe  means  of  discriminating 
between  pyroxene  and  amphibole,  since  the  mem- 
bers of  both  groups  exhibit  greenish  and  brownish 
tints.  The  augites  and  hornblendes  which  occur 
in  basalt  are  mostly  brownish  in  color. 

The  hornblende  in  syenite  is  also  generally 
brown,  but  that  which  occurs  in  phonolite  is  mostly 
of  a  greenish  tint,  while  the  augite  in  leucite  lavas 
is,  as  a  rule,  also  green. 

The  minerals  of  the  amphibole  group  frequently 
show  a  tendency  to  develop  long  blade-like  crystals. 
This  tendency  is  in  a  very  marked  degree  shown  by 
actinolite,  one  of  the  principal  varieties  of  amphi- 
bole, the  crystals  arranging  themselves  in  radiate 
groups. 

Both  hornblende  and  augite  occur  together  in  the 
same  rock,  but  as  a  rule  the  former  mineral  is  found 
in  those  rocks  which  contain  a  large  percentage  of 
silica,  the  associated  minerals  being  usually  quartz 
and  orthoclase,  while  augite  is  generally  found  in 
rocks  of  a  basic  character  containing  tri clinic  feld- 
spars, and  with  little  or  no  free  silica. 

Chlorite,  occurs  sometimes  in  thin,  foliated 
plates  like  mica,  but  inelastic,  oftener  granular, 
massive ;  sometimes  in  green  crystals  and  scales. 
These  kinds  of  chlorite  are  found  in  rocks  and  form 
the  mass  of  chlorite  rock  and  chlorite  slate. 

The  chlorites  are  silicates  of  alumina,  iron  and 
magnesia  with  water,  the  average  percentage  of 
magnesia  being  about  34  and  that  of  water  over  12. 

Chlorite  is  a  very  soft  mineral  and  is  essentially 
a  product  of  the  decomposition  of  other  minerals. 


PREPARATORY   INSTRUCTION.  11 

When  heated  in  a  glass  tube  it  gives  off  water. 
Before  the  blowpipe  it  exfoliates,  whitens  and  melts 
with  difficulty  into  a  greyish  enamel.  It  is  soluble 
in  hydrochloric  acid  when  powdered,  and  after  long 
boiling. 

Talc.  A  hydrated  silicate  of  magnesia  from 
which  the  water  is  only  driven  off  at  a  high  tem- 
perature. It  generally  occurs  in  broad  pale  green 
or  silvery  whitish  plates  or  leaves,  looking  like 
mica,  but  the  cleaved  plates,  though  flexible,  are 
much  softer  and  not  elastic.  It  is  easily  scratched 
by  the  nail,  has  a  pearly  lustre  and  is  soapy  and 
unctuous  to  the  touch.  Before  the  blowpipe  it 
turns  white  and  exfoliates.  It  is  neither  before  or 
after  ignition  soluble  in  either  hydrochloric  or  sul- 
phuric acid,  thus  differing  from  chlorite. 

Serpentine.  This  is  also  a  hydrated  silicate  of 
magnesia.  It  is  usually  compact,  massive,  not 
granular  at  all,  of  a  dark  green  color,  but  varying 
from  pale  green  to  greenish  black.  The  most 
peculiar  variety  is  a  fibrous  kind  occurring  in 
seams  in  massive  serpentine,  which  is  called 
crysotile,  popularly  called  asbestus. 

Minerals  are  composed  of  chemical  elements, 
which  are  substances  which  cannot  be  further  sepa- 
rated. A  table  of  the  chemical  elements,  their  synr 
bols,  equivalents  and  specific  gravities,  is  given  in 
the  Appendix.  When  these  elements  unite  together 
and  form  a  compound,  they  always  do  so  in  fixed 
proportion  and  in  definite  weight.  Therefore,  in 
any  pure  mineral,  whose  composition  is  known,  the 


12        prospector's  field-book  and  guide. 

amounts  of  the  elements  going  to  make  up  any 
given  mass  of  it  can  be  calculated  by  a  rule  of 
three  sum. 

For  example,  in  galena  (PbS)  we  have  lead  (Pb) 
=  207  and  sulphur  (S)=32,  total  239.  Therefore, 
in  239  lbs.  of  pure  galena  we  will  find  207  lbs.  of 
lead  (86J  per  cent.),  and  so  on  in  proportion. 

Thus  any  mineral  that  is  pure  enough  to  be 
weighed  directly,  or  which  can  be  concentrated  pure 
and  then  weighed,  can  be  estimated  in  this  way,  and 
the  percentage  content  of  the  ore  calculated. 

The  combination  of  two  or  more  of  these  elements 
together  gives  rise  to  three  classes  of  substances, 
namely,  acids,  bases,  and  salts. 

Oxides  of  non-metallic  elements  are  acid. 

Oxides  of  metallic  elements  are  bases. 

Where  an  acid  and  a  base  unite,  one  exactly 
neutralizing  the  other,  a  substance  is  produced  hav- 
ing neither  acid  nor  basic  tendency.  It  is  known 
as  a  salt. 

Most  minerals  are  salts.  There  is  only  one  com- 
mon acid  mineral,  namely,  quartz  (S202),  or  the 
oxide  of  the  non-metallic  element  silicon. 

There  are  many  minerals  which  are  basic,  such  as 
hematite  (Fe203)  and  magnetite  (Fe304),  the  oxides 
of  iron,  and  cuprite  (CuO),  the  oxide  of  copper. 

Among  the  many  minerals  which  are  salts  are 
common  salt  or  sodium  chloride  (NaCl) ;  limestone 
or  calcite  (CaC03),  formed  from  the  union  of  the 
oxide  of  calcium  (metal)  and  carbonic  acid  gas ; 
gypsum  (CaS042H  0),  formed  by  the  union  of  the 


PREPARATORY    INSTRUCTION.  13 

oxide  of  calcium  (metal)  and  sulphuric  acid ;  apatite, 
phosphate  of  lime  [Ca3(P204)2] ,  formed  by  the  same 
base  as  above  uniting  with  phosphoric  acid. 

There  are  a  great  many  minerals  the  acid  member 
of  which  is  silica,  with  one  or  more  metallic  oxides 
forming  the  basic  member.  These  are  known  as 
silicates,  and  feldspar,  mica,  hornblende,  pyroxene, 
talc,  serpentine,  etc.,  are  examples. 

These  facts  are  important  to  remember,  because 
whole  families  of  minerals  and  rocks  are  classified 
acid  or  basic  according  to  the  greater  or  lesser 
quantity  of  silica  present  in  them. 

The  colors  of  minerals  are  either  essential  to 
them,  as  in  the  sulphides,  oxides  and  acidiferous 
compounds  of  most  metals,  and  in  those  species  of 
which  they  are  essential  constituents ;  or  they  are 
the  effect  of  casual  intermixture  of  these  substances 
in  species  which,  when  pure,  are  naturally  colorless. 
Of  the  latter  sort  are  the  colors  of  feldspar,  calcspar, 
rock  salt,  marble,  and  jasper,  in  which  the  various 
tints  of  red  and  yellow  are  generally  due  to  the 
oxide  and  hydrous  oxide  of  iron.  Other  minerals 
derive  a  brilliant  green  color,  some  from  carbonate 
of  copper,  others  from  the  oxide  of  nickel  or  of 
chrome.  In  species  of  which  the  color  is  a  perma- 
nent character,  its  intensity  is  often  so  far  varied  by 
a  difference  of  texture  or  confused  crystallization, 
that  red,  brown,  and  green  substances  appear,  in  a 
mass,  to  be  black  ;  but  on  being  pulverized,  their 
true  color  will  be  seen.  It  is  therefore  advisable, 
in  describing  a  mineral,  to  state  what  its  color  is 
when  reduced  to  powder. 


14        prospector's  field-book  and  guide. 

The  intermixtures  of  coloring  matter,  which  are 
merely  mechanical,  render  a  mineral  more  or  less 
opaque  ;  thus  the  red  and  yellow  jasper  are  chalce- 
dony— which  when  pure  is  highly  translucent,  or 
even  semi-transparent — colored  by  minute  particles 
of  oxide  of  iron,  which  are  themselves  opaque.  But 
colors,  which,  though  they  may  not  be  essential  to  a 
species,  are  the  result  of  chemical  combination,  do 
not  impair  its  transparency  ;  such  is  the  violet  tint 
of  amethyst,  which  is  derived  from  a  minute  por- 
tion of  the  oxide  of  manganese  combined  with  the 
quartz  ;  and  the  green  of  the  emerald,  which  may 
in  some  cases  be  due  to  oxide  of  chrome. 

In  consequence  of  the  variable  quantity  of  color- 
ing matter,  whether  chemically  combined  or  other- 
wise, many  substances  present  various  tints  and 
shades  of  color,  so  that  they  are  particularized  as 
blood  red,  flesh  red,  chestnut  brown,  lemon-yellow, 
sky-blue,  etc. 

Accidental  colors  being  unequally  distributed, 
often  produce  parallel  bands,  either  straight  or 
curved,  and  clouded  forms,  as  in  agates.  Some- 
times the  color  takes  the  form  of  leaves  and  moss, 
or  runs  through  the  mass  in  veins,  as  in  marble. 

There  are  still  other  colors,  which  are  neither 
essential  to  minerals,  nor  yet  produced  by  intermix- 
ture. Some,  as  the  sulphide  of  antimony,  exhibit 
a  brilliant  superficial  tarnish,  in  which  the  pris- 
matic colors  are  regularly  arranged.  In  transparent 
substances,  prismatic  colors  are  perceived  in  the  in- 
terior,  and   arise   from   minute  cracks  or  fissures 


PREPARATORY    INSTRUCTION.  15 

containing  films  or  particles  of  air ;  these  are  often 
movable  by  slight  pressure. 

A  very  curious  peculiarity  of  color  called  poly- 
chroism  is  connected  with  the  phenomenon  of 
double  refraction.  Some  minerals,  placed  between 
the  eye  and  the  light,  transmit  different  colors  in 
different  directions.  Tourmalines,  viewed  parallel 
to  their  axis,  are  generally  opaque  ;  perpendicularly 
to  it,  they  appear  to  be  green,  red,  brown,  etc. 
This  difference  is  not  observable  in  all  double 
refracting  substances  ;  but  in  some  which  have  two 
axes  of  double  refraction  three  different  tints  have 
been  observed.  Minerals  crystallizing  in  the  cubic 
system  never  transmit  more  than  one  color,  if  their 
composition  and  texture  be  homogeneous  through- 
out. 

In  some  minerals  a  peculiar  light  is  produced 
either  by  friction  or  heating  them,  which  is  called 
phosphorescence.  On  rubbing  together  two  frag- 
ments or  pebbles  of  quartz,  a  faint  greenish  light 
will  be  perceived,  and  the  same  effect  can  be  pro- 
duced with  certain  marbles.  Other  substances 
when  placed  on  a  heated  shovel,  emit  a  brilliant 
phosphorescence,  which  in  some  is  green  ;  in  others 
pale  violet.  The  best  mode  of  conducting  this 
experiment,  if  the  specimen  is  powdered,  or  in 
small  fragments,  is  to  strew  it  over  a  shovel  heated 
nearly  to  redness ;  but  if  it  be  an  inch  or  two  in 
length,  it  is  better  to  heat  it  slowly,  and  not  beyond 
the  necessary  degree,  by  which  means  the  operation 
may  be  frequently  repeated  without  injuring  the 
specimen. 


16 

Some  metals  are  found  native  and  in  some  degree 
of  purity,  as  in  the  cases  of  gold,  silver,  copper, 
mercury,  and  platinum,  and  when  so  found  are 
readily  determined  at  once  by  any  one  who  is  at  all 
acquainted  with  those  metals  as  they  occur  in  gen- 
eral use.  But  frequently  native  metals  appear 
under  such  colors,  and  even  forms,  that  the  dis- 
coverer must  possess  more  knowledge  than  any  one 
usually  possesses  who  has  seen  the  metal  in  the  arts 
only.  Gold,  as  an  illustration,  is  frequently  found 
in  various  shades  of  yellow,  in  accordance  with  the 
amount  of  silver  or  copper  it  may  contain,  and  yet 
to  the  practiced  eye  of  a  true  mineralogist  it  never 
loses  the  true  gold  hue. 

Iron  pyrites,  which  is  composed  of  sulphur  and 
iron,  and  called  "pyrite,"  mineralogically,  has  a 
color  somewhat  similar  to  that  of  gold,  and  so  also 
has  a  mineral  called  "  chalcopyrite,"  or  copper 
pyrites,  which  contains  copper,  iron  and  sulphur. 
These,  with  others,  vary  in  the  yellow  shade,  and 
degrees  of  color,  but  by  the  practiced  eye  are  in- 
stantly detected.  Of  course  the  brittleness  of  these 
minerals  is  unlike  the  softness  of  native  gold,  and 
this  would  instantly  reveal  the  fact  that  they  were 
not  gold ;  but  we  are  now  speaking  of  the  practiced 
eye  alone,  and  therefore  of  the  benefit  of  cultivating 
a  knowledge  by  sight  of  minerals.  The  mode  in 
which  a  mineral  breaks  when  smartly  struck  with 
a  hammer,  or  pressed  with  the  point  of  a  knife,  is  a 
character  of  importance.  Many  minerals  can  only 
be   broken   in   certain   directions,    for   instance,   a 


PREPARATORY    INSTRUCTION.  17 

crystal  of  calc  spar  can  only  be  split  parallel  to  the 
faces  of  a  rhombohedron  ;  many  crystals  break  more 
readily  in  one  direction  than  in  others.  Whenever 
a  mineral  breaks  with  a  smooth,  flat,  even  surface, 
it  is  said  to  exhibit 

Cleavage  which  always  depends  upon  the  crys- 
talline form.  But  minerals  often  break  in  irregular 
directions,  having  no  connection  whatever  with  the 
crystalline  form,  and  this  kind  of  breaking  is  called 

Fracture.  The  nature  of  the  surface  given  by 
fracture  is  often  a  character  of  importance,  especially 
in  distinguishing  the  varieties  of  a  mineral  species. 
Thus  quartz  and  many  mineral  species  show  a 
shell-like  fracture-surface  which  is  called  conchoidal, 
or  if  less  distinct,  small  conchoidal  or  sub-conchoidal 
More  commonly  the  fracture  is  simply  said  to  be 
uneven,  when  the  surface  is  rough  and  irregular. 
Occasionally  it  is  hackly,  like  a  piece  of  fractured 
iron.  Earthy  and  splintery  are  other  terms  some- 
times used  and  readily  understood. 

Streak.  The  color  and  appearance  of  the  line  of 
furrow  on  the  surface  of  a  mineral,  when  scratched 
or  rubbed,  is  called  the  streak,  which  is  best  ob- 
tained by  means  of  a  hard-tempered  knife  or  a  file. 
The  color  of  a  mineral  and  its  streak  may  corre- 
spond, or  the  mineral  and  its  streak  may  possess 
different  colors,  or  the  mineral  may  be  colored  while 
its  streak  is  colorless.  For  instance,  cinnabar  has 
both  a  red  color  and  a  red  streak  ;  specular  iron  has 
a  black  color,  but  a  red  streak  ;  sapphire  has  a  blue 
color,  but  a  white  colorless  streak.  The  streak  of 
2 


18        prospector's  field-book  and  guide. 

most  minerals  is  dull  and  pulverulent,  but  a  few 
exhibit  a  shining  streak  like  that  formed  on  scratch- 
ing a  piece  of  lead  or  copper.  This  kind  of  streak 
is  distinguished  by  the  name  of  'metallic.  In  judg- 
ing the  streak  of  a  mineral,  much-weathered  pieces 
should  be  rejected. 

Hardness  is  another  character  of  great  impor- 
tance in  distinguishing  minerals  ;  it  is  the  quality  of 
resisting  abrasion.  The  diamond  is  the  hardest  sub- 
stance known,  as  it  will  scratch  all  others.  Talc  is 
one  of  the  softest  minerals.  Other  minerals  possess 
intermediate  degree  of  hardness.  To  express  how 
hard  any  mineral  is,  it  becomes  necessary  to  com- 
pare it  with  some  known  standard.  Ten  standards 
of  different  degrees  have  been  chosen,  and  are  given 
in  order  in  the  following  scale  : 

1.  Talc,  easily  scratched  by  the  finger-nail. 

2.  Gypsum,  does  not  easily  yield  to  the  finger- 
nail, nor  will  it  scratch  a  copper  coin. 

3.  Calcite,  scratches  a  copper  coin,  but  is  also 
scratched  by  a  copper  coin. 

4.  Fluorite,  is  not  scratched  by  a  copper  coin,  and 
does  not  scratch  glass. 

5.  Apatite,  scratches  glass  with  difficulty ;  is 
readily  scratched  by  a  knife. 

6.  Feldspar,  scratches  glass  with  ease ;  is  difficult 
to  scratch  by  a  knife. 

7.  Quartz,  cannot  be  scratched  by  a  knife,  and 
readily  scratches  glass. 

8.  Topaz, 

9.  Corundum, 


>  harder  than  flint  or  quartz. 


PREPARATORY    INSTRUCTION.  19 

10.  Diamond,  scratches  any  substance. 

If  on  drawing  a  knife  across  a  mineral  it  is  im- 
pressed as  easily  as  calcite,  its  hardness  is  said  to 
be  3.  If  a  mineral  scratches  quartz,  but  is  itseif 
scratched  by  topaz,  its  hardness  is  between  7  and  8. 

In  trying  the  hardness  of  a  mineral,  a  sound  por- 
tion of  the  mineral  should  be  chosen  and  a  sharp 
angle  used  in  trying  to  scratch.  A  streak  of  dust 
on  scratching  one  mineral  with  another  may  come 
from  the  waste  of  either,  and  it  cannot  be  deter- 
mined which  is  the  softer  until  after  wiping  off  the 
dust  and  examining  with  a  lens. 

By  the  test  of  hardness,  clear  distinctions  may  be 
drawn  between  minerals  which  resemble  each  other. 
Iron  pyrites  and  copper  pyrites,  for  instance,  are 
similar  in  appearance,  but  copper  pyrites  can  easily 
be  scratched  with  a  knife,  while  iron  pyrites  is 
nearly  as  hard  as  quartz  and  the  knife  makes  no 
impression  upon  it. 

Flexibility  and  elasticity.  Some  minerals 
can  be  readily  bent  without  breaking,  for  instance; 
talc,  mica,  chlorite,  molybdenite,  native  silver,  etc. 
Minerals  which  after  being  bent  can  resume  their 
former  shape  like  a  steel  spring,  are  called  elastic, 
for  instance,  mica  and  elaterite.  A  remarkable  in- 
stance of  flexibility,  even  combined  with  elasticity, 
amongst  the  rocks,  is  that  of  a  micaceous  sandstone 
cailed  itacolumite,  which  in  Brazil  is  the  matrix 
of  the  diamond. 

Smell.  A  few  minerals  only,  like  bitumen,  have 
a  strong    smell   which  is   readily   recognized,   but 


20        prospector's  field-book  and  guide. 

specimens  generally  require  to  be  struck  with  a 
hammer,  rubbed,  or  breathed  upon  before  any  smell 
can  be  observed.  Some  black  limestones  have  a 
bituminous  odor,  while  some  have  a  sulphurous, 
and  others  a  foetid,  smell.  Hydraulic  limestone 
has  a  smell  of  clay  which  can  be  detected  when  the 
mineral  is  breathed  on.  Some  minerals  containing 
much  arsenic,  for  instance  mispickel,  smell  of  garlic 
when  struck  with  a  hammer. 

Taste.  Only  soluble  minerals  have  any  taste,  and 
this  can  only  be  described  by  comparison  with  well- 
known  substances,  for  instance  acid,  vitriol ;  pungent, 
sal  ammoniac  ;  salt,  rock  salt ;  cooling,  nitrite  ;  astrin- 
gent, alum ;  metallic  astringent,  sulphate  of  copper ; 
bitter,  sulphate  of  magnesia  ;  sweet,  borax. 

Malleability.  Malleable  substances  can  be 
hammered  out  without  breaking,  and  it  is  on  this 
quality  that  the  value  of  certain  metals  in  the  arts 
depends,  for  instance,  copper,  silver,  gold,  iron,  etc. 

A  few  minerals  are  malleable,  and  at  the  same 
time  sectile,  i.  e.,  they  can  be  cut  with  a  knife,  for 
instance,  silver  glance,  horn  silver  and  ozokerite. 

Mineral  caoutchouc  (elaterite)  is  sectile,  but  like 
india  rubber,  can  only  be  shaped  when  hot.  The 
elasticity  of  elaterite  is  so  characteristic  that  the 
mineral  will  be  readily  recognized. 

Ductility,  or  the  capability  of  being  drawn  into 
wire,  is  a  property  which  is  confined  exclusively  to 
certain  metals.  It  is  possessed  in  the  highest  degree 
by  gold,  which  can  be  drawn  into  the  finest  wire, 
or  rolled  into  leaves  of  such  fineness  that  30,000  of 
them  are  not  thicker  than  an  eighth  of  an  inch. 


PREPARATORY    INSTRUCTION.  21 

Lustre.  The  term  lustre  is  employed  to  describe 
with  certain  adjectives,  the  brilliancy  or  gloss  of 
any  substance.  In  describing  the  lustre  well-known 
substances  are  taken  as  the  types,  and  such  terms  as 
adamantine  lustre — diamond-like — and  vitreous  lustre 
— glassy — are  used.  The  lustre  of  a  mineral  is 
quite  independent  of  its  color.  When  minerals  do 
not  possess  any  lustre  at  all  they  are  described  as 
"  dull."  The  kinds  of  lustre  distinguished  are  as 
follows : 

Metallic :  The  lustre  of  a  metallic  surface  as  of 
steel,  lead,  tin,  copper,  gold,  etc. 

Vitreous,  or  glassy  lustre :  That  of  a  piece  of  broken 
glass.  This  is  the  lustre  of  most  quartz  and  of  a 
large  part  of  non-metallic  minerals. 

Adamantine:  This  is  the  lustre  of  the  diamond. 
It  is  the  brilliant,  almost  oily,  lustre  shown  by 
some  very  hard  materials,  as  diamond,  corundum, 
etc.  When  sub-metallic  it  is  termed  metallic  ada- 
mantine, as  seen  in  some  varieties  of  white  lead  ore 
or  cerussite. 

Resinous  or  waxy :  The  lustre  of  a  piece  of  rosin, 
as  that  of  zinc  blende,  some  varieties  of  opal,  etc. 
Near  this,  but  quite  distinct,  is  the  greasy  lustre, 
shown  by  some  specimens  of  milky  quartz. 

Pearly  or  the  lustre  of  mother-of-pearl.  This  is 
common  where  a  mineral  has  very  perfect  cleavage. 
Examples :  Talc,  native  magnesia,  stilbite,  etc. 

Silky,  like  silk.  This  is  the  result  of  fibrous 
structure,  as  the  variety  of  calcite  (or  of  gypsum) 
called  satin  spar,  also  of  most  asbestus. 


22        prospector's  field-book  and  guide. 

Specific  gravity.  Prospectors  soon  acquire 
some  proficiency  in  testing  the  weight  of  minerals 
by  handling  them.  A  lump  of  pyrite,  for  instance, 
can  readily  be  distinguished  from  gold  by  its  weight, 
since  a  mass  of  gold  of  the  same  size  would  weigh 
at  least  three  times  as  much,  and  a  little  practice 
with  well-known  substances  will  enable  the  pros- 
pector to  class  most  minerals  within  certain  broad 
limits  by  weighing  them  in  the  hand. 

The  specific  gravity  of  a  mineral  is  its  weight 
compared  with  water  at  a  standard  temperature  and 
pressure,  which  is  taken  as  the  standard,  and  de- 
scribed as  having  a  specific  gravity  of  1 ;  conse- 
quently, to  determine  that  of  a  mineral,  it  is  neces- 
sary to  find  the  weight  of  a  piece  of  the  mineral  and 
that  of  a  corresponding  bulk  of  water,  and  to  divide 
the  first  by  the  last.  This  can  be  done  with  great 
accuracy  in  the  laboratory,  where  delicate  balances 
are  available,  but  is  not  applicable  in  the  field,  when 
the  most  that  can  be  undertaken  is  to  class  minerals 
roughly  within  certain  broad  limits,  and  indeed, 
this  is  generally  sufficient  for  the  prospector.  Some 
rules  for  finding  weights  by  specific  gravity  are 
given  in  the  Appendix. 

What  has  previously  been  said  of  color  may  also 
be  said  of  weight  and  form.  A  lump  of  pyrite  in 
the  hands  of  a  skilled  mineralogist  would  be  dis- 
tinguished from  gold  by  its  weight,  since  as  above 
mentioned,  a  mass  of  gold  of  the  same  size  would 
weigh  at  least  three  times  as  much.  Three  crystal- 
line pieces,  the  one  of  barite,  the  other  two  of  lime 


PREPARATORY    INSTRUCTION.  23 

carbonate  and  of  quartz,  may  to  the  unskillful  eye 
appear  equally  transparent ;  but  the  form  of  the 
first  is  tabular,  that  of  the  latter  two  is  in  six-sided 
crystals,  but  the  lime  carbonate  crystals  terminate 
in  three  sides,  while  the  quartz  always  (like  the 
sides)  in  six. 

Besides  a  knowledge  of  the  forms  under  which  the 
minerals  we  seek  present  themselves,  it  is  also  neces- 
sary to  learn  the  characteristics  of  some  of  the  rocks 
which  are  generally  associated  with  those  minerals. 
The  object  of  this  knowledge  is  to  serve  in  directing 
us  to  those  regions  where  we  may  with  greater  prob- 
ability discover  the  minerals  we  seek.  It  also  serves 
to  wTarn  us  out  of  a  region  where  we  should  not 
expect  to  find  what  we  desire. 

To  illustrate,  we  may  not  expect  to  find  iron  ores 
of  a  certain  kind,  brown  hematites  for  instance,  in  a 
granitic  country.  On  the  other  hand,  we  may  find 
the  magnetic  ores  in  such  a  region,  and  it  is  useless 
to  explore  a  granitic  region  for  black  band  iron  ore, 
although  it  may  be  the  proper  region  to  discover 
red  hematite. 

It  is,  therefore,  important  that  the  prospector 
should  be  able  to  distinguish  many  of  the  geologic 
rocks  to  help  in  guiding  or  in  checking  him,  in  his 
explorations. 

A  general  knowledge,  therefore,  of  the  manner  in 
which  the  geologic  rocks  are  "  laid  down,"  their 
order,  or  succession,  in  the  earth,  is  important,  and 
the  distinction  between  sedimentary  and  that  which 
has  been,  and  is  usually  called  "  igneous  rock,"  but 


24 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


more  properly  "  azoic  rock,"  that  is,  rock  which 
does  not  exhibit  any  remains  of  fossil  or  organic 
life.  For  often  the  only  signs  by  which  we  can, 
with  any  degree  of  certainty,  determine  what  is  the 
name  of  the  sedimentary  rock  is  by  finding  the  re- 
mains of  former  life,  that  is,  the  kind  of  fossil  it 
contains.  Prof.  Dana  says  (The  Amer.  Journal  of 
Science,  Nov.  and  Dec,  1890)  that  it  is  settled  that 

Fig.  1. 


Section  showing  contorted  strata  due  to  lateral  pressure:  aa,"  anti- 
clinal axis ; "  c,  the  "  synclinal  axis."  The  direction  of  the  arrows,  ee,  ee,  is 
that  of  "  the  strike."  That  of  the  arrows,  dd,  is  that  of  "the  dip"  of  the 
strata,  always  measured  from  the  horizon  ;  gg,  are  the  out-crops. 

the  kind  of  rock  in  itself  considered  is  not  a  safe 
criterion  of  geological  age. 

If  all  the  rocks  in  the  world  had  been  laid  down 
in  regularly  horizontal  sequence  and  had  always  re- 
mained in  their  own  separate  "  horizons,"  as  every 
rock  of  the  same  age  is  called,  not  only  should  we 
find  them  all  parallel,  one  over  the  other,  but  we 


PREPARATORY  INSTRUCTION.  25 

might  readily  determine  to  some  extent  what  were 
the  exact  order  and  distance  of  any  one  horizon,  or 
geological  age.  But,  although  there  is  a  general 
order,  the  same  in  all  parts  of  the  world,  there  have 
been  upheavals  and  sinkings,  dislocations  and  ero- 
sions, during  the  ages,  so  that  it  is  necessary  that 
the  prospector  should  become  acquainted  with  the 
various  changes  probable  in  the  order  and  forms  of 
the  vast  rocks  which  carry  the  minerals  for  which 
he  is  seeking. 

Some  of  these  movements  of  the  earth's  crust  are 
represented  in  Fig.  1. 

PRACTICAL  GEOLOGY. 

We  repeat  that  it  is  of  considerable  importance 
that  the  prospector  should  have  at  least  some  general 
knowledge  of  those  geological  horizons  with  which 
his  work  is  specially  associated.  As  we  have  inti- 
mated, useful  minerals  do  not  always  confine  them- 
selves to  one  horizon  ;  but  there  are  certain  ranges 
of  rock  which  indicate  their  vicinity.  There  are 
also  limits  which  are  never  overpassed  by  some  use- 
ful minerals,  and  experience  has  shown  that  some 
horizons  are  always  sterile  in  ores,  and  it  is  there- 
fore useless  ever  to  expect  to  find  them  in  paying 
quantities,  in  certain  rocks  or  beyond  them  in  cer- 
tain directions. 

Gold  often  occurs  where  it  will  not  pay  to  'open 
and  work  the  strata,  so  also  with  lead  and  copper. 
It  is  well  to  learn  the  relations  of  such  barren 
regions,  or  horizons,  as  the  strata  are  called. 


26        prospector's  field-book  and  guide. 

In  the  following  table  we  have  given  chief  place 
to  these  horizons  which  have  been  found  in  our 
own  country  to  abound  in  the  useful  minerals,  and 
we  advise  the  possession  of  small  specimens  of  the 
principal  rocks  mentioned  and  the  special  examina- 
tion of  the  specimens  under  a  good  lens,  so  as  to 
become  thoroughly  acquainted  wTith  their  appear- 
ance and  their  minute  parts  of  composition. 

All  rocks  may  be  classified  as — 

1.  Igneous. 

2.  Metamorphic. 

3.  Aqueous. 

Speaking  geologically,  not  only  the  hard  consoli- 
dated, massive  and  stony  substances  are  called 
"  rocks,"  but  any  natural  deposits  of  stony  material 
such  as  sand,  earth,  or  clay,  when  in  natural  beds, 
are  geological  rocks.  Very  few  of  the  rocks  of  this 
earth,  at  any  rate  so  far  as  examined,  are  in  their 
original  and  primal  condition.  Even  the  granites 
and  volcanic  rocks  are  composed  of  other  and  more 
ancient  material  disintegrated,  ground  up,  or  worn 
down,  settled,  buried,  and  compressed  by  ages  of 
enormous  pressure,  or  consolidated  by  cementation. 
Some  have  been  "laid  down"  under  water,  having 
been  disintegrated  into  dust,  carried  by  the  winds  of 
ages  out  over  the  oceans  and  seas,  and  settled  down 
into  the  form  of  the  present  rocks,  which  afterward 
have  been  lifted  up  into  mountains  and  plains  above 
the  seas.  But  by  the  transporting  power  of  rivers 
or  currents  in  ancient  oceans,  and  because  of  un- 
equal upheaval  of  some  regions  where  subterranean 


PREPARATORY    INSTRUCTION.  27 

forces  were  greater  than  at  distant  places,  very  large 
differences  in  the  nature  of  the  deposit  have  occurred, 
even  in  limited  regions.  These  special  and  limited 
forces  will  account  for  the  fact  that  although,  taking 
the  geological  horizons  throughout  the  world,  there 
is  a  general  sameness,  differences  do  occur,  and 
important  members  of  the  order  of  succession  are 
omitted  in  some  regions,  and  exceptions  to  general 
rules  occur. 

In  the  table  following  are  therefore  given  those 
universally  accepted  relations  of  certain  rocks,  one 
to  another,  in  the  great  geologic  arrangement  of  the 
world,  omitting  some  of  the  subsidiary,  limited, 
and  unimportant  horizons. 

1.  IGNEOUS  ROCKS  are  such  as  have  been  sub- 
jected to  sufficient  heat  to  melt  the  ingredi- 
ents.    Of  these  rocks — 

Volcanic  rocks  are  those  which  have  been  cooled 
near  or  at  the  surface,  as  lava,  etc. 

Trachyte :  A  grayish  rock  of  rough  fracture  ;  the 
same  specific  gravity  as  quartz,  but  mainly 
constituted  of  grains  of  glassy  feldspar.  It 
is  essentially  a  unisilicate  of  alumina,  with 
10  to  15  per  cent,  potash,  a  little  soda  and 
lime ;  differs  from  quartz  in  that  it  fuses 
before  the  blow-pipe,  while  quartz  remains 
unfused  except  when  soda  is  used. 

Basalt :  Blackish  or  dark  brown.  Traps,  green- 
stone, dolerite,  amydolite;  these  latter  four  are 
only  modifications,  being  all  unisilicates  with 


28        prospector's  field-book:  and  guide. 

smaller  amounts  of  potash  than  in  trachyte, 
a  little  more  soda  and  lime,  and  some  traces 
of  iron  and  magnesia,  varying  in  color  and 
form. 
Obsidian  is  a  glass,  something  like  bottle  glass, 
of  a  dark  shade,  and  translucent. 
All  these  are  compact  in  texture  except  where 
some  holes  have  been  worn  in  by  steam  or  gases. 
They  are  frequently  found  penetrating  several  strata, 
having  been  forced  up  in  columns  almost  vertically, 
and  sometimes  spreading  out  horizontally  for  many 
miles  between  the  strata  or  on  the  surface,  and  are 
called  volcanic  dykes,  or  intrusive  rocks  or  lava. 
These  and  such-like  are  igneous  rocks. 

It  is  not  certain  that  granite  rocks  are  of  igneous 
origin,  but  they  seem  to  belong  to  the  metamorphic 
series. 

2.  METAMORPHIC  ;  these  are  of  igneous,  subse- 
quently to  the  time  when  they  were  of  aque- 
ous origin,  and  have  undergone  a  change 
through  pressure  and  heat,  and,  perhaps,  in 
connection  with  steam  or  water.  Of  this 
class  are  the  following  : 

Gneiss,  having  a  composition  of  small  pieces  of 
feldspar,  mica,  and  quartz,  like  some  gran- 
ites, but  laminated  or  foliated  in  form,  and 
not  equally  solid,  homogeneous,  and  contin- 
uous throughout  its  structure  as  granite  is. 

Mica  Schist.  This  term  is  given  to  those 
laminated  rocks  composed  of  mica  and  quartz 


STRATIFIED  ROCKS. 

GENERAL    DIVISIONS. 

SUBDIVISIONS. 

■ — 

CHARACTERISTICS. 

RECENT 

PLEISTOCENE 

oe  QUARTERNARY. 

All  its  shells  and  bones 
are  of  existing  species. 

About  50  per  cent,  of  ex- 
isting species  of  shells. 

Contains  80  per  cent,  of 
extinct  species. 

Contains  fresh  water  and 
marine  strata,  animals  all 
extinct. 



si 

ss 

WO 
H 

PLIOCENE. 
MIOCENE. 
EOCENE. 

CRETACEOUS. 

Upper. 
Middle. 

Lower. 

Cha^^h^tCs""118'  bUt  the  L0W" }  se^urc^nfetf  mati°"D  M*S  ^^  """"«""• 
Contains  Greensand  in  England  and  in   New  .Tmsev,  used  as  a  marl  and   fertilizer     There  is  a 
supposed  Cretaceous  lignite  in  Alaska,  Colorado,  California.  Utah,  etc. 

0 
PO 

JURASSIC. 

Lias 

Whealden. 

Consists  of  sand,  clay,  or  marl,  the  sand  used  in  glass  making. 

Portland  Stone. 

Oxford  Group. 

Stonesfield  Slate. 

Some  English  coal  is  found  in  the  Oolite.    Kimmeridge  clai  is  founi  1  In  upper  Oolite ;  tho  flno 

Bavarian  lithographic  stone  in  the  middle  Oolite. 

b3 

Limestone  in  horizontal 
strata. 

Conspicuous  for  the  number  of  ammonites  and  nautilus  shells.     Furnishes  building  and  paving 
stone. 

TRIASSIC. 

Keuper. 

Muschelkalk. 

Bunter-sandstone. 

Called  by  the  Germans  TRIAS. 

Connecticut  river  sandstone  with  footprints. 

Red  clays,  marls,  shales  and  sandstones.     The  New  Red  Sandstone  of  Knghind. 

In  Europe  great  salt  beds. 

PERMIAN. 

Dark  red  sandstone. 
Magnesian  limestone. 
Conglomerates,  Breccias, 
Marls  in  all  three. 

Mostly  sandstones  and  marlytes,  some  impure  magnesian   limestone  and  gvpsuin.     'I'Ium     >  .on. 

of  coal,'  unworkable.  With  exception  of  BROWN  HEMATITE  iron  ore  and  the tali  a tiei 

above,  all  the  other  metals  are  found  in  the  formations  below. 

o 

N 

2 

CARBONIFEROUS. 

Seams  of  Anthracite  and 
bituminous  coals  of  vary- 
ing thickness. 

Millstone  grit. 
Subcarboniferous. 

The  black  band  iron  ore.    Limestone  from  the  same  mineswltb  the  coal  In  Qreal   Britain,  bui 

not  so  frequently  in  America.     Anthracite,  cannel,  and   bituminous  coal  In 
sandstone,  and  shales,  forming  the  "  The  Coal  Measures." 

Affords  PETROLEUM  in  Pennsylvania,  Ohio,  and  elsewhere,  and  salines  in  Michigan,     " 
MOUNTAIN"  LIMESTONE  of  England.    Largely  of  corals. 

0 

2 

DEVONIAN. 

Catskill  Period. 
Chemung  Period. 
Hamilton  Period. 
Corniferous  Period. 

includes  the  OLD  RED  SANDSTONE  OP  ENGLAND. 

Hamilton  black  shales  produce  oil;  the  Hamilton  beds  afford  excellent  Bo 

Corniferous  called  also  Upper  Helderberg  group. 

Upper 
SILURTAN. 

Lower 

Oriskany  Sandstone. 

Lower  Heldeiberg  Period. 

Salina  Period. 

Niagara  Period. 

Salina  Period  supplies  the  salt  waters  of  Salina  and  Syracuse,  N.  Y. 

Trenton  Period. 
Canadian  Period. 
Potsdam  Sandstone. 

The  LEAD  MINES  of  Iowa  and  Wisconsin  are  in  the  Magnesian   Limestone  of  the  Canadian 
Period. 

Cambrian. 
Laurentian. 
ARCH/EAN. 

(Between  pages  28  and  2<J. ) 

PREPARATORY    INSTRUCTION. 


29 


in  small  particles,  easily  broken  up,  but  more 
easily  broken  into  tabular  or  leaf-like  pieces, 
because  the  mica  has  been  deposited  in 
planes  allowing  of  cleavage. 

3.  THE  AQUEOUS  KOCKS  are  simple  water 
rocks — that  is,  rocks  composed  of  sediments 
from  the  dust  or  ground-up  remains  of  other 
rocks.  The  presence  of  such  sediments  is 
due  to  the  transporting  power  of  rivers, 
floods,  or  currents,  and  also  of  winds  and 
storms  and  other  agencies,  carrying  the  dust 

Fig.  2. 


Sandstone. 

to  the  ocean  waters  where  it  was  arrested 
and  became  a  sediment. 
In  sandstone  (Fig.   2),   the  grains  of  sand  are 
rounded,  having  no  sharp  edges  as  in  granite. 

Where  the  sedimentary  material  was  exceedingly 
dust-like,  it  sometimes  is  laid  down  as  fine  mud  and 
frequently  in  lamina,  as  in  shale  (Fig.  3). 

Granite  is  a  term  descriptive  of  rocks  generally 


30        prospector's  field-book  and  guide. 

composed  of  quartz,  feldspar  and  mica,  in  grains 
(hence  the  name)  of  a  crystalline  form.  But  the 
granites  are  not  all  alike  in  the  amount  of  either  of 
the  above-mentioned  minerals,  nor  are  they  alike  in 
color.  Some  granites  contain  no  mica,  as  in  graphic 
granite,  only  quartz  and  feldspar,  and  the  quartz  in 
the  feldspar  resembling  written  characters.  Others 
contain  hornblende  as  well  as  mica,  or  in  the 
place  of  mica ;  the  hornblende  being  in  dark  or 
black    crystalline   specks,    pieces,   or   crystals,    and 

Fig.  3. 


Shale. 


consisting  essentially  of  silica,  magnesia,  lime,  and 
iron.  This  granite  is  called  syenite  granite.  Where 
the  feldspar  is  in  dictinct  crystals  in  compact  base, 
and  sometimes  lighter  than  the  base,  which  is  fre- 
quently reddish,  purple,  or  dark  green,  it  is  a  por- 
phyritic  granite.  The  granites  are  sometimes  whit- 
ish, grayish,  or  flesh-red.  They  are  considered  as 
metamorphic  and  not  igneous  (Dana),  although 
some  authors  still  consider  them  to  be  igneous- 
They  always  present  a  crystalline  grain  in  varying 
degrees  of  fineness  and  prominence.     One  form  is 


PREPARATORY    INSTRUCTION.  31 

given  in  Fig.  4,  from  a  specimen  in  the  author's 
possession. 

This  specimen  contains  two  kinds  of  mica,  one 
black,  biotite,  the  other  white,  of  silvery  appearance, 
muscovite.  The  biotite  presents  in  spots  the  appear- 
ance of  hornblende,  and  only  the  pen-knife  point 
shows  the  scaly  lamination  of  mica  under  the  lens. 
It  also  contains  crystalline  forms  of  potash  feldspar 
(orthoclase),  distinguishable  from  the  quartz  by  their 
side  only,  by  the  lamellar  fracture  of  its  edges,  and 
its   peculiar  vitreous   glimmer,  for  practically  the 

Fig.  4. 


Granite  with  black  mica  and  feldspar  crystals,  with  quartz  as  chief  base. 

hardness  appears  the  same,  although  feldspar  is  (6.6 
and  quartz  7)  slightly  softer.  It  would  be  well  for 
the  prospector  to  gather  many  forms  of  granite  and 
examine  them  under  the  lens  until  he  becomes 
throughly  used  to  the  variations. 

The  first  indications  of  a  deposit  possessing 
economic  value  are,  as  a  rule,  to  be  met  with  among 
the  materials  forming  the  beds  of  streams,  and 
wherever  water-courses  have  seamed  and  furrowed 
the  rocks.  Metalliferous  deposits  should  be  looked 
for   in    hilly   districts   as   a   general  rule,  though 


32        prospector's  field-book  and  guide. 

alluvial  accumulations  may  be  found  in  compara- 
tively flat  country.  A  close  study  of  natural  phe- 
nomena will  often  help  in  the  discovery  of  mineral 
wealth.  Thus  the  form  and  color  of  the  surface; 
stained  patches ;  springs  of  water  whether  sweet  or 
mineralized ;  scum  floating  on  water  (petroleum, 
etc.);  accumulations  of  earth  brought  to  the  surface 
by  burrowing  animals  ;  changes  in  vegetation  ;  be- 
havior of  the  magnetic  needle.  These,  however, 
only  serve  to  indicate  existence  without  reference  to 
quantity  or  quality. 

The  valuable  minerals  and  metal-bearing  deposits 
of  the  earth  occur  as 

Lodes.  By  a  lode  or  vein  is  generally  meant  a 
fissure  in  the  rocky  crust  of  the  earth  which  is  filled 
with  mineral  matter.  In  Australia  a  vein  is  called 
a  reef  and  in  California  a  ledge.  The  course  of  a 
lode  in  a  horizontal  direction  is  called  its  strike, 
while  its  descent  is  spoken  of  as  its  dip.  Very  often 
lodes  are  distinctly  marked  off  from  the  rocks  en- 
closing them  by  straight  and  sharp  divisions  on 
either  side  of  the  lode  as  if  cut  with  a  knife. 
These  divisions  are  called  the  walls  of  the  lode. 
When  the  lode  inclines  in  its  dip  to  either  one  side 
or  the  other,  which  is  nearly  always  the  case,  the 
upper  division  is  called  the  hanging-wall,  and  the 
lower  the  foot-wall.  The  incline  of  the  lode  in  its 
dip  is  its  underlie.  The  barren  rock  through  which 
the  lode  passes  is  known  amongst  mining  men  as 
the  "  country."  Lodes  may  be  all  widths  from  a 
thin  thread-like  film  to  100  feet  or  more  in  width. 


PREPARATORY    INSTRUCTION.  33 

Lodes  often  contain  large  blocks  of  the  country 

Fig.  5. 

A 


id 

Formation,  cross  section. 
I,  I,  I,  I,  country  rock  enclosed  in  lode  on  horse,  surrounded  by  auriferous 
quarts.    A,  A,  hanging  wall ;  B,  B,  foot  wall ;  C,  C,  casing  ;  D,  D,  D,  D, 
country  rock. 

rock  barren  of  ores  or  metals,  which  are  therefore 
waste.     Such  occurrences  are  spoken  of  as  forma- 
3 


34 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


tions  or   horse,  and  are   generally   of  great  width 
between  the  two  walls.     See  Fig.  5. 

Lodes  nearly  always  carry  casing,  which  is  coun- 
try rock  ground  very  fine,  converted  into  clay  by 
moisture  and  mixed  with  quartz  and  free  native 
gold.  The  casing  mostly  occurs  on  the  foot-wall, 
and  is  often  very  rich  in  metal.     Fig.  6. 

Fig.  6. 


Showing  solid  quartz  lode,  with  casing.    Transverse  section. 
1, 1,  solid  quartz  lode  without  horse;  2,  2,  casing  of  soft  dig ;  3,  hanging  wall 
4,  foot-wall ;  5,  5,  country  rock. 

Beds  and  layers.  The  most  common  of  bedded 
deposits  are  those  of  coal.  Many  kinds  of  iron  ore 
are  found  in  beds,  also  some  copper  ores  in  shale, 
silver  and  lead  ore  in  sandstone,  etc.  Beds  and 
layers  are  also  known  as  strata,  measures,  sills,  mines, 
bassets,  delfs,  girdles. 


PREPARATORY    INSTRUCTION.  35 

Irregular  deposits,  such  as  pockets,  etc.,  which  lie 
sometimes  in  various  formations.  Contact  deposits, 
net-work  of  veins,  and  where  mineral  is  diffused 
through  rocks,  or  in  small  cracks. 

Surface  deposits.  By  surface  deposits  are  under- 
stood the  beds  of  alluvium  which  more  or  less  cover 
the  face  of  every  country.  These  beds  have  been 
chiefly  created  by  various  mechanical  agents,  which, 
after  having  degraded  the  higher  rocks,  carry  the 
material  which  has  thus  been  formed  down  to  lower 
levels.  By  this  process  of  degradation  most  mineral 
deposits  are  so  comminuted  that  by  their  exposure 
to  the  atmosphere  they  are  decomposed  and  de- 
stroyed. However,  substances  like  cassiterite,  plat- 
inum, gold,  etc.,  not  being  so  readily  subject  to  de- 
composition, have,  in  consequence,  been  more  or 
less  preserved  and  buried  among  these  superficial 
deposits.  In  observing  deposits  of  this  kind  notice 
has  to  be  taken  of  their  general  situation,  area, 
thickness  and  richness.  Often  several  beds  may  be 
ranged  one  above  the  other,  in  which  case  their 
relative  values  have  to  be  determined.  In  tracing 
any  particular  deposit,  as,  for  example,  whilst 
ascending  a  valley,  if  the  particles  of  ore  increase 
in  size  and  number,  the  prospector  may  expect 
that  he  is  approaching  their  common  origin.  An- 
other indication  that  he  is  near  this  point  of 
origin  will  be  that  he  shall  find  the  mineral  less 
worn. 

Comprehensively  speaking,  all  metals  are  found 
in  the  oldest  rocks  only,  and  the  latter  form  the 


backbone,  so  to  speak,  of  the  main  ranges  of  metal- 
liferous countries.  Therefore,  the  prospector  in 
making  his  road  towards  the  mountains  will  have 
to  select  a  spot  for  starting  actual  operations.  For 
this  purpose  a  locality  should  be  chosen  where  the 
rocks  are  neither  too  hard  nor  too  soft,  nor  should 
they  be  of  too  uniform  a  character.  The  country 
most  deeply  indented  with  gullies,  canons  and 
gulches  running  parallel  to  one  another  offers  the 
best  chances  of  success.  The  region  near  the 
sources  of  the  main  rivers  is  generally  the  richest 
in  metals  and  always  the  most  easily  prospected,  re- 
quiring less  labor  and  time  in  its  examination,  the 
loose  debris  and  wash  being  of  much  lesser  depth 
on  account  of  the  greater  fall  in  the  river  and  creek 
beds  than  at  other  portions  of  their  courses. 

Auriferous  lodes  are  most  likely  to  be  met  with 
near  the  headwaters  of  river  systems,  and  very  fre- 
quently the  alluvial  gold  begins  at  or  near  the 
locality  where  a  number  of  auriferous  lodes  exist. 
This  is  a  very  common  occurrence,  and  may  be  in 
the  great  majority  of  cases  relied  upon. 

When  a  river  forks  at  its  head  into  two  or  more 
branches,  it  is  strange  to  say,  the  source  of  the  gold 
will  nearly  always  be  found  in  the  right-hand 
branch,  geographically  speaking.  It  may  be  men- 
tioned that  in  determining  the  right  and  left-hand 
branches  or  banks  of  a  river  or  stream,  you  are  sup- 
posed to  stand  at  the  head  of  the  river  or  stream 
looking  towards  its  mouth  or  outlet.  Amongst 
miners  this  is  very  often  reversed,  and  quite  a  num- 


PREPARATORY    INSTRUCTION.  37 

ber  of  branches  are  named  left-hand  which,  properly- 
speaking,  ought  to  be  right-hand  branches. 

This  right-hand  theory  is  an  old  mining  supersti- 
tion for  which  science  has  offered  no  explanation, 
but  the  almost  unfailing  applicability  of  the  theory 
is  fully  established  by  practical  experience.  Speak- 
ing of  mining  superstitions,  it  may  be  added  that 
the  spots  upon  which  the  sun  shines  before  noon 
are  held  by  miners  to  be  richest  in  metal.  Every 
old  gold  miner  will  pin  his  faith  to  this  theory. 
What  makes  these  observed  facts — for  they  really 
amount  to  that — all  the  more  remarkable  is,  that 
they  may  be  applied  with  an  equal  degree  of  liabil- 
ity to  the  Northern  and  to  the  Southern  hemispheres, 
which  makes  these  superstitions  appear  in  a  para- 
doxal light.  However,  they  have  survived  the  test 
of  hundreds  of  years  in  Cornwall  and  on  the  Conti- 
nent of  Europe,  and  have  been  confirmed  by  further 
observations  in  California  and  Australia.  The  latter 
instance,  i.  e.,  the  spots  upon  which  the  sun  shines 
before  noon,  may  find  an  explanation  in  the  fact 
that  landslides  and  elevations  of  rock  of  all  kinds 
are  of  more  frequent  occurrence  upon  the  sunny, 
than  upon  the  shady,  side  of  valleys,  the  greater 
amount  of  disintegration  of  the  rocks  leading  to  a 
greater  accumulation  of  the  metals.  However  this 
may  be,  the  theory  forms  one  of  the  golden  rules  of 
the  prospector. 

The  color  of  the  rocks  also  serves  as  a  guide  to  the 
prospector.  Rocks  of  a  pinkish-reddish  color  alter- 
nating with  rocks  of  a  deep  bluish  tint  streaked 


with  drab  are  generally  very  favorable  to  metallic 
deposits.  Another  good  indication  is  when  the 
faces  of  the  precipices  are  covered  with  a  black 
ooze  caused  by  manganese,  the  presence  of  which 
always  indicates  a  mineralized  district.  These  are 
simply  general  indications. 

Although  color  is  always  a  good  guide  to  the 
location  of  metallic  deposits,  it  is  of  special  service 
to  the  prospector  in  unexplored  districts.  Thus 
copper  is  indicated  by  greenish,  bluish,  or  reddish 
stains  upon  the  rocks  in  the  neighborhood  of  the 
lode ;  tin  and  manganese,  by  dull  black  tints, 
manganese  shows  itself  also  in  pinkish  streaks. 
Gold,  being  always  accompanied  with  iron,  mani- 
fests its  presence  in  red,  yellow,  or  brown  shades; 
lead  and  silver  reveal  grey  or  bluish-grey  tinges ; 
blende  dyes  the  rocks  yellowish-brown  ;  and  iron 
disports  itself  in  all  the  hues  of  red,  yellow-brown, 
and  even  dun-black. 

The  wash  of  rivers  and  creeks,  and  even  more  so 
that  deposited  upon  terraces  (if  any)  flanking  the 
streams,  must  claim  the  close  attention  of  the  pro- 
spector. By  wash  is  meant  the  diluvial  drift  in 
which  gold  or  tin  —  the  only  metals  mined  in 
diluvial  deposits — is  found.  The  colors  in  connec- 
tion with  the  different  metals  mentioned  above, 
apply  also  to  stones  and  the  wash  generally,  though 
in  a  modified  degree.  Stones  streaked  with  pinkish 
lines,  and  lines  indicating  manganese,  are  always 
found  in  wash  conveying  gold.  Green  stones,  which 
are  universally  found  in  the  wash,  are  always  a 


PREPARATORY    INSTRUCTION.  39 

good  indication  of  gold  if  they  are  of  a  bright  sea- 
green  or  even  pea-green,  but  they  must  be  smooth, 
hard,  well-polished  and  very  heavy.  In  many  dis- 
tricts such  stones  are  considered  the  "  pilot  stones  " 
to  gold.  Quartz  stones  must  be  always  present  in 
goodly  numbers  in  every  gold-bearing  wash,  and  if 
they  are  in  a  decaying  state,  they  are  all  the  better 
as  a  favorable  indication. 

The  greater  portion  of  the  gold  which  has  come 
into  the  possession  of  man  has  been  obtained  from 
superficial  deposits,  called  placers.  Deposits  of 
placer  gold  are  always  found  adjacent  to  and  lying 
below  districts  traversed  by  auriferous  veins,  and 
nowhere  else.  The  areas  where  the  quartz  veins 
occur  have  suffered  great  erosion,  which  has  tended 
to  break  down  and  comminute  the  quartz,  and  to 
liberate  and  wash  the  contained  gold. 

Placer  gold  is  found  mingled  with  rolled  frag- 
ments of  quartz  and  in  the  irregularities  of  the 
surface  of  the  bed-rock  where  a  washing  process  on 
a  large  scale  has  been  active. 

The  nuggets  and  coarsest  gold  are  found  nearest 
the  outcrops  of  the  quartz  veins  that  have  sup- 
plied them,  while  particles  become  gradually  finer 
and  finer  as  the  line  of  drainage  is  followed  from 
this  point. 

Pebbles  and  fragments  of  gold  bearing  quartz 
which  have  been  derived  from  the  neighboring 
veins  are  commonly  found  in  the  placer  deposits, 
and  most  of  the  nuggets  have  more  or  less  quartz, 
like  that  of  the  veins  still  adhering  to  them.     The 


40 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


gold  is  found  in  scales,  grains,  pebble-like  nodules 
and  round  battered  masses  or  nuggets. 

The  domain  of  the  prospector  lies  in  hilly 
ground.  Flat  plains  have  little  attraction  for  him 
except  under  special  conditions ;    because,  though 

Fig.  7. 


m* 


h:^^m^smm^ 


valuable  minerals  may  be  present,  they  are  certain 
to  be  covered  by  an  enormous  deposit  of  soil. 

In  character  placer  diggings  manifest  almost  as 
great  variety  as  vein  deposits.  The  following  illus- 
trations show  in  section  some  forms  of  these  alluvial 
deposits : 

The  stream  (Fig.  7)  flows  across  the  strike  of  the 
rocks,  and  the  gold  is  found  below  a  hard  bar ;  a, 


Fig.  8. 


surface  of  stream ;  b,  mud  and  gravel  forming  bed 
of  stream ;  c,  bed  rock ;  d,  auriferous  gravel  re- 
tained by  the  projection  of  the  bed  rock. 


PREPARATORY    INSTRUCTION. 


41 


In  Fig.  8,  the  stream  flows  as  in  Fig.  7  across 
the  strike  of  the  rocks,  but  the  gold  is  found  on  one 
side  of  the  creek,  a,  bank  of  stream  ;  b,  mud  and 
other  worthless  matter  lying  on  the  pay  dirt:  c, 
auriferous  gravel  accumulated  in  the  deepest  parts 
of  the  stream. 

In  Figs.  9  and  10,  a,  represents  the  stream ;  b, 
mud  and  gravel  at  bottom  of  stream ;  c,  bed  rock ; 

Fig.  9. 


Flu.  10. 


d,  pot  holes  in  bed-rock  where  auriferous  material 
has  lodged. 

In  Figs.  9  and  10,  the  stream  generally  runs 
with  the  strike  of  the  rocks,  or  at  a  slight  angle ; 
but  the  dip  is  nearly  perpendicular  in  those  in- 
stances where  pot-holes  have  been  known  to  occur. 

In  estimating  the  value  of  alluvial  claims  it  is  of 
the  utmost  importance  to  consider  the  cheapness 
and  abundance  of  the  water  supply  and,  which  is  of 


42 

no  less  importance,  the  facilities  afforded  by  the 
surrounding  levels  for  the  disposal  of  the  debris  of 
the  mining  operations  or  waste  material,  called 
tailings,  from  which  the  gold  has  been  excavated  or 
removed,  so  that  the  gold-bearing  layer  may  be 
reached. 

Indicative  Plants.  From  very  early  times  it 
has  been  noticed  that  the  soil  overlying  mineral 
veins  is  favored  by  special  vegetation,  and  though 
the  occurrence  of  such  vegetation  cannot  be  taken 
as  an  infallible  indication  of  the  existence  of  such 
veins,  it  will  be  interesting  to  record  the  results  of 
past  observations,  so  that  they  may  serve  for  a 
guidance  to  further  observation  in  future. 

Indication  of  lead.  The  lead  plant  (Amorpha 
canescens)  is  said  by  prospectors  in  Michigan,  Wis- 
consin and  Illinois,  to  be  most  abundant  in  soils 
overlying  the  irregular  deposits  of  galena  in  lime- 
stones. It  is  a  shrub  one  to  three  feet  high,  cov- 
ered with  a  hoary  down.  The  light  blue  flowers 
are  borne  on  long  spikes,  and  the  leaves  are  ar- 
ranged in  close  pairs  on  stems,  being  almost  devoid 
of  foot-stalks. 

Gum  trees,  or  trees  with  dead  tops,  as  also  sumac 
and  sassafras,  are  observed  in  Missouri  to  be  abund- 
ant where  "  float "  galena  is  found  in  the  clays. 

Indication  of  iron.  A  vein  of  iron  ore  near  Siegen, 
Germany,  can  be  traced  for  nearly  two  miles  by 
birch  trees  growing  on  the  outcrop,  while  the  re- 
mainder of  the  country  is  covered  with  oak  and 
beech. 


PREPARATORY    INSTRUCTION.  43 

Indication  of  limestone.  The  beech  tree  is  almost 
invariably  prevalent  on  limestone,  and  detached 
groups  of  beech  trees  have  led  to  discoveries  of  un- 
suspected beds  of  limestone. 

Indication  of  phosphate.  The  phosphate  miners 
in  Estremadura,  Spain,  find  that  the  Convolvulus 
althseoides,  a  creeping  plant  with  bell-shaped  flowers, 
is  a  most  reliable  guide  to  the  scattered  and  hidden 
deposits  of  phosphorite  occurring  along  the  contact 
of  the  Silurian  shales  and  Devonian  dolomite. 

Indication  of  silver.  In  Montana  experienced 
miners  look  for  silver  wherever  the  Eriogonum  ovali- 
folium  flourishes.  This  plant  grows  in  low  dense 
bushes,  its  small  leaves  coated  with  thick  white 
down,  and  its  rose-colored  flowers  being  borne  in 
clusters  on  long  smooth  stems. 

Indication  of  zinc.  The  "  zinc  violet,"  Galmeiveil- 
chen  or  Kelmesblume  (Viola  calaminaria)  of  Rhenish 
Prussia,  and  neighboring  parts  of  Belgium,  is  there 
considered  an  almost  infallible  guide  to  calamine 
deposits,  though  in  other  districts  it  grows  where  no 
zinc  ore  has  been  found.  In  the  zinc  districts  its 
flowers  are  colored  yellow,  and  zinc  has  been  ex- 
tracted from  the  plant.  The  same  flower  has  been 
noticed  at  zinc  mines  in  Utah. 

In  looking  for  indications  where  superficial  depos- 
its are  known  to  occur,  the  prospector  may  be  often 
guided,  like  the  Tungusians  in  Northern  Siberia, 
who  search  for  gold  by  first  looking  at  the  general 
contour  of  the  country,  and  observing  those  places 
where  any  obstacles,  like  a  projecting  range  of  hills, 


44        prospector's  field-book  and  guide. 

would  be  likely  to  prevent  material  from  being 
directly  washed  from  higher  to  lower  ground. 
Holes,  sudden  bends,  or  anything  which  would 
cause  a  diminution  in  the  force  of  a  current  of 
water,  are  points  at  which  it  should  be  expected 
that  heavy  material  like  gold  or  platinum  would  be 
likely  to  collect.  Although  in  Australia  the  most 
gold  is  generally  found  in  pot  holes  and  behind 
hard  bars,  it  has  often  been  found  upon  the  shallow 
bends  of  ancient  river  courses.  The  lowest  of  a 
series  of  beds  is  generally  the  richest.  In  California 
the  gold-bearing  beds  usually  consist  of  gravels, 
which  may  be  cemented  to  form  a  conglomerate, 
sands,  bands  of  tuff,  clay,  fossil-wood,  etc. 

Magnetite  occurs  in  alluvial  deposits.  Bog  iron 
and  manganese  ore  which  have  accumulated  by 
precipitation  in  marshy  places  or  in  lakes  usually 
contain  too  much  impurity  to  be  of  commercial 
value.  Stream  tin  occurs  in  gravels  in  much  the 
same  way  as  gold. 

In  examining  a  lode,  the  nature  of  the  various 
minerals  it  contains  and  the  proportions  which 
these  hold  to  each  other  should  be  observed.  Some- 
times it  will  be  noticed  that  certain  groups  of  min- 
erals are  often  found  together,  the  presence  of  one 
being  favorable  to  the  existence  of  the  other.  At 
other  times  the  reverse  will  be  remarked,  the  exist- 
ence of  one  mineral  being  the  sign  of  the  absence  of 
another.  The  practical  advantages  to  be  derived 
from  a  series  of  observations  indicating  such  results 
are  too  obvious  to  be  overlooked. 


PREPARATORY    INSTRUCTION. 


45 


The  following  table,  showing  the  association  of 
ore  in  metalliferous  veins,  is  given  by  Phillips  and 
Von  Cotta : 


Two  Members. 


Galena,  blende. 


Iron    pyrites,    chal 
copyrites. 


Gold,  quartz. 


Cobalt    and    nickel 
ores. 


Tin  ore,  wolfram. 
Gold,  tellurium. 


Cinnabar,  tetrahe- 
drite. 


Magnetite,  cblorite. 


Three  Members. 


Galena,    blende,   iron 
pyrites  (silver  ores). 


c  Iron  pyrites,  chalcopy- 
■s  rite,  quartz  (copper 
^     ores). 


Gold,  quartz,  iron  py- 
rites. 


Cobalt  and  nickel  ores, 
and  iron  pyrites. 


Tin,    ore,    wolfram, 
quartz. 

Gold,  tellurium,  tetra- 
hedrite  (various  tel- 
lurium ores). 

Cinnabar,  tetrahedrite, 
pyrites  (various  ores 
of  quicksilver). 


Magnetite,    cblorite, 
garnet. 


Four  or  More  Members. 

Galena,  blende,  iron  pyri- 
tes, quartz  and  spatbic 
iron,  diallogite,  brown 
spar,  calc  spar  or  beavy 
spar. 

Iron  pyrites,  cbalcopyrite, 
galena,  blende ;  and 
spatbic  iron,  diallogite 
brown  spar,  calc  spar; 
or  beavy  spar. 

Gold  quartz,  iron  pyrites, 
galena  blende ;  and 
spatbic  iron,  diallogite ; 
brown  spar,  calc  spar, 
or  heavy  spar. 

Cobalt  and  nickel  ores, 
iron  pyrites;  and  galena, 
blende,  quartz,  spathic 
iron  ore,  diallogite . 
brown  spar;  calc  spar; 
or  heavy  spar. 

Tin  ore,  wolfram,  quartz, 
mica,  tourmaline,  topaz, 
etc. 

Gold,  tellurium,  tetrahe- 
drite, quartz,  and  brown 
spar ;  or  calc  spar. 

Cinnabar,  tellurium,  tetra- 
hedrite, pyrites,  quartz 
and  spathic  iron,  diallo- 
gite, brown   spar,  calc 
spar ;  or  heavy  spar. 

Magnetite,  chlorite,  gar- 
net, pyroxene,  horn- 
blende, pyrites,  etc. 


CHAPTER  II. 

THE    BLOW-PIPE    AND    ITS   USES. 

All  chemical  tests  for  minerals,  whether  with 
the  blow-pipe  or  in  the  wet  way,  depend  upon  some 
chemical  change  which  is  brought  about,  thus 
allowing  the  element,  base  or  acid,  to  be  recognized. 
These  changes  consist  either  of  the  decomposition  of 
the  mineral,  or  the  formation  of  fresh  compounds. 
The  following  instances  will  sufficiently  illustrate 
the  character  of  these  changes. 

If  the  oxide  of  a  metal,  copper  for  instance,  is 
mixed  with  carbonate  of  soda  and  fused  on  char- 
coal, the  copper  is  reduced  to  a  metallic  state,  the 
oxygen  combining  with  the  charcoal  to  form  car- 
bonic acid,  which  escapes  as  a  gas,  and  any  silica 
which  is  present  decomposes  the  carbonate  of  soda 
to  form  a  silicate  of  soda,  which  may  be  looked 
upon  as  a  slag. 

If  a  hydrous  mineral  is  heated  in  a  glass  tube 
closed  at  one  end,  the  water  is  given  off,  and  con- 
denses as  drops  in  the  cool  part  of  the  tube. 

If  an  arsenical  mineral  is  heated  in  a  closed  tube 
a  crystalline  deposit  of  arsenic  is  formed  in  the 
tube ;  but  if  it  is  heated  in  the  air,  white  fumes  of 
arsenious  acid  are  evolved  which  smell  like  garlic. 

(46) 


THE    BLOW-PIPE    AND    ITS    USES.  47 

If  a  drop  of  hydrochloric  acid  be  placed  on  a  car- 
bonate, such  as  limestone,  the  presence  of  carbonic 
acid  is  recognized  by  the  effervescence  which  takes 
place ;  the  stronger  acid  having  combined  with  the 
lime  has  liberated  the  carbonic  acid  in  a  gaseous 
form.  In  the  case  of  very  many  mineral  car- 
bonates, the  acid  requires  to  be  heated  for  this  re- 
action. 

A  great  deal  can  be  learned  respecting  a  mineral 
by  a  few  simple  trials  with  the  blow-pipe,  and  every 
prospector  should  learn  to  use  it.  The  chief  re- 
quirements are  a  plain  brass  blow-pipe  about  7  to  10 
inches  long,  a  candle,  a  forceps  or  pliers,  some 
platinum  wire,  a  small  pestle  and  mortar  made  of 
agate,  a  small  sieve,  a  magnet,  some  small  glass 
tubes,  and  some  good  firm  charcoal  free  from  cracks 
and  openings. 

The  only  reagents  which  will  be  absolutely  neces- 
sary are  borax,  carbonate  of  soda  and  rarely  micro- 
cosmic  salt,  nitrate  of  cobalt,  and  a  little  hydro- 
chloric and  sulphuric  acid.  A  few  others  are 
occasionally  necessary,  but  their  use  is  limited. 
The  carbonate  of  soda  should  be  perfectly  dry,  not 
merely  dry  to  the  touch  but  quite  free  from  water. 
Such  carbonate  of  soda  may  be  prepared  from  com- 
mon washing  soda  by  expelling  the  water  it  con- 
tains. Put  the  washing  soda  in  a  shallow,  clean 
iron  dish,  and  place  it  over  a  clear  fire  until  a  white 
dry  power  is  formed ;  avoid  too  strong  a  heat, 
otherwise  the  dry  powder  might  fuse.  A  quarter  of 
an  ounce  may  be  kept  in  a  well-corked  bottle  or 


48        prospector's  field-book  and  guide. 

tube  for  use.  Bicarbonate  of  soda  may  be  used  in. 
stead  without  previous  heating,  or  if  the  bicarbonate 
be  moderately  heated  it  loses  weight,  and  becomes 
carbonate  of  soda,  quite  free  from  water,  like  the 
above. 

The  borax  is  to  be  dried  in  the  same  way  ;  a 
quarter  of  an  ounce  will  be  enough.  It  is  conven- 
ient to  keep  the  platinum  wire  in  the  same  tube. 
Unless  these  tubes  are  well  corked,  these  chemicals 
reabsorb  moisture.  For  testing  tin  ore  it  is  useful 
to  have  a  little  cyanide  of  potassium  kept  in  a  bottle, 
with  the  cork  and  rim  well  covered  with  melted 
beeswax ;  it  would  otherwise  liquefy  by  absorption 
of  moisture  and  become  useless.  It  is  a  most  dan- 
gerous poison,  and  the  greatest  caution  must  be  ob- 
served in  its  use. 

The  blow-pipe  should  have  a  fine  jet,  or  aperture? 
wide  enough  to  admit  of  a  fine  needle.  The  mode 
of  using  it  may  be  readily  acquired  by  first  breath- 
ing through  the  nostrils  with  the  lips  closed,  then 
puffing  out  the  cheeks  (as  if  rinsing  the  mouth  with 
water),  still  keeping  the  lips  closed,  and  breathing 
as  before.  The  blow-pipe  may  at  this  point  be 
slipped  between  the  lips,  and  it  will  be  found  that  a 
current  of  air  escapes  through  it  without  any  effort 
on  the  part  of  the  operator.  Air  flows  through  the 
pipe  owing  to  the  tendency  of  the  distended  cheeks 
to  collapse ;  it  must  never  be  forced  from  the  lungs. 
After  a  little  practice  the  strength  of  the  current 
may  be  increased.  By  breathing  entirely  through 
the  nostrils,  keeping  the  lips  closed,  the  blast  may 


THE    BLOW-PIPE    AND    ITS    USES.  49 

be  kept  up  for  ten  minutes  or  longer  without  ex- 
haustion or  inconvenience,  except  a  slight  fatigue 
of  the  lips  in  holding  the  blow-pipe.  The  beginner 
may  practice  blowing  upon  a  piece  of  charcoal. 
The  charcoal  should,  for  convenience  sake,  be  cut 
into  slices  of  some  six  inches  long  by  three-quarters 
to  an  inch  wide  and  half  inch  thick.  Place  a  piece 
of  lead,  or  a  pin-head,  or  fragment  of  pyrite  (iron 
pyrites),  near  the  end  of  the  charcoal,  and  learn  to 
blow  the  flame  of  a  candle  to  a  point  upon  the 
object.  However  awkward  the  blow-pipe  may  feel 
at  first,  practice  will  soon  enable  the  learner  to  be 
expert.  At  first  it  may  be  necessary  to  gouge  a 
small  hole  or  recess  in  the  coal  with  the  point  of 
your  pen-knife,  in  order  to  prevent  the  specimen 
from  being  blown  away.  But  after  many  trials 
such  a  command  will  be  had  over  the  blast  that  the 
hole  may  be  made  sufficiently  deep  by  simply  turn- 
ing the  point  of  the  flame  upon  the  coal  and  burn- 
ing out  a  cavity. 

Study  the  two  colors  of  a  sperm  candle  flame 
(Fig.  11).  Notice  that  there  is  a  yellow  flame  out- 
side and  nearer  the  top,  and  then  within  the  flame 
there  may  be  seen  a  bluish,  probably  a  true  blue 
flame.  These  flames  act  differently  on  the  same 
substance.  The  outer  0  F,  or  yellow  flame,  is 
called  the  "  oxidizing  flame,"  the  inner,  the  "  reducing 
flame,"  R  F  or  I  F.  By  blowing  properly,  these 
two  flames  may  be  made  to  turn  horizontally,  or 
even  downward,  and  then  either  the  0  flame  or  the 
R  flame  may  be  turned  on  the  "  assay  "  (as  the  ob- 
4 


50 


PROSPECTOR  S    FIELD-BOOK   AND   GUIDE. 


ject  on  the  charcoal  may  be  called).  Get  a  piece  of 
iron  ore  as  large  as  a  pin-head  and  place  it  in  a 
little  cavity  on  the  charcoal,  then  cover  it  with  a 
quantity  of  soda  carbonate  as  large  as  the  assay. 
Now  turn  the  R  flame  down  on  the  soda  and  ore, 
and  in  a  few  seconds  the  ore  will  melt  and  be  re- 
duced to  metallic  iron,  and  your  magnetized  knife- 

FlG.  11. 


A,  the  blue  or  reducing  flame ;  B,  the  oxidizing  flame ;  C,  the  end  of  the 
blow-pipe. 


By  placing  the  end  of  the  blow-pipe  in  the  flame  thus,  the  oxidizing  flame, 
A,  is  made  more  efficient. 


blade  will  pick  it  and  the  soda  up.  In  this  experi- 
ment a  piece  of  red  or  brown  hematite,  or  a  piece  of 
pyrite  (iron  pyrites),  should  be  used,  as  neither  will 
be  attracted  by  the  knife-blade  before  the  ore  is  re- 
duced to  metallic  iron.  The  reason  for  this  action 
on  the  part  of  the  ore  is  that  the  ore  is  metallic  iron 
combined  with  oxygen,  and  the  R  or  blue  flame  calls 


THE    BLOW-PIPE   AND    ITS    USES.  51 

for  more  oxygen  than  it  possesses,  so  that  when  it  is 
turned  upon  the  hot  oxide  of  iron  it  takes  the 
oxygen  it  calls  for,  from  the  ore  and  leaves  the  iron 
in  a  metallic  state.  But  in  the  pyrite,  which  is  iron 
and  sulphur,  the  latter  is  partially  driven  off  by 
either  flame ;  and  this  process,  on  a  larger  scale,  is 
called  "roasting."  The  soda  absorbs  a  part  of  the 
sulphur  and  part  remains  in  the  iron,  but  not  so 
much  but  that  the  magnetized  knife-blade  will  at- 
tract it.  The  last  experiment  is  good  for  experi- 
mental practice,  but  not  for  illustrating  the  two 
properties  of  the  flame. 

The   following  is  an  excellent  illustration  and 
practice  in  showing  the  characteristic  power  of  either 

Fig.  12. 
1/  //////////  i ^ 

Appearance  and  size  of  wire  and  loop,  A. 

flame.  Get  some  platinum  wire  of  the  size  of  a 
large  horse-hair.  Wrap  it  around  a  match,  leaving 
an  end  extending  an  inch  and  a  half  beyond  the 
match  end,  then  roll  the  end  of  the  wire  around 
another  match  until  you  have  bent  the  end  of  the 
wire  into  a  small  loop  (Fig.  12).  Prepare  a  little 
powder  of  common  borax,  and  then,  heating  the 
wire  loop  in  the  general  flame,  plunge  it  quickly 
into  the  powdered  borax.  It  will  immediately  pick 
up  a  quantity  of  the  powder,  and  then,  by  turning 
the  flame  upon  the  borax,  you  will  have  a  clear  and 


52 

perfectly  transparent  bead  filling  the  little  loop  on 
the  end  of  the  wire.  You  are  now  ready  for  the 
experiment  of  illustrating  the  special  properties  of 
the  two  flames,  which  we  shall  now  describe. 

Obtain  some  black  oxide  of  manganese,  from  any 
druggist,  and  dropping  a  little  upon  a  clean  sheet 
of  letter  paper,  heat  your  borax  bead  red-hot  in  the 
flame  and  quickly  touch  with  the  hot  bead  a  parti- 
cle of  the  black  oxide — it  will  stick  to  the  bead — 
then  turn  the  outer  or  0  flame  upon  the  bead  and 
blow  till  the  particle  of  oxide  of  manganese  has  en- 
tirely dissolved — it  will  impart  to  the  bead  a  beauti- 
ful amethystine-purple.  Now  turn  the  inner  flame, 
that  is,  the  R  flame,  upon  the  bead,  and  in  a  few 
seconds  (according  to  skill  in  keeping  the  R  flame 
steadily  on  the  bead)  the  color  will  disappear,  but  it 
will  return  when  the  0  flame  is  used  again. 

These  efforts  will  give  practice,  ending  in  suffi- 
cient skill  to  enable  the  learner  to  use  the  blow-pipe 
as  directed  in  the  future  parts  of  this  work. 

The  various  reactions  of  different  substances  are 
given  in  the  body  of  this  book  as  they  are  called  for 
when  the  substances  are  described. 

A  glass  tube  of  a  little  less  than  three-eighths  of  an 
inch  in  diameter  may  be  made  into  a  blow-pipe  as 
follows :  Take  a  piece  of  such  a  tube,  ten  or  twelve 
inches  long,  soften  the  tube  by  red  heat  in  an  alco- 
hol flame,  and  draw  it  out  to  a  small  diameter — 
cool  and  scratch  or  file  it  at  the  smallest  diameter 
— -break  it  off,  introduce  the  tube  into  the  flame 
again  and  bend  the  glass  to  a  right  angle,  about 


THE   BLOW-PIPE   AND   ITS   USES.  53 

two  inches  off  from  the  point — cool  gradually — and 
heat  the  mouth  end,  opening  it  a  little  by  introduc- 
ing a  small  dry  pine  stick,  cool  it,  and  you  have  a 
very  efficient  blow-pipe  when  another  of  metal  can- 
not be  had. 

Note:  If  your  platinum  loop  will  not  hold  the 
borax  bead,  then  it  is  too  large.  Make  a  smaller 
loop.  If  it  is  dimmed  or  blackened  by  smoke,  heat 
it  red-hot — it  will  clear  up. 

The  three  principal  means  of  chemically  testing 
minerals  before  the  blow-pipe  are  (1)  with  borax  ; 
(2)  on  charcoal,  usually  with  the  addition  of  car- 
bonate of  soda ;  (3)  by  holding  in  the  oxidizing 
point. 

In  connection  with  this  the  following  experiments 
given  by  Alexander  M.  Thomson,  D.  Sc.,  are  of  in- 
terest : 

Experiment  No.  1. — Many  metals  impart  a  color 
to  fused  borax,  by  which  their  presence  can  be 
recognized.  To  try  this  experiment,  a  bead  of 
fused  borax  must  first  be  obtained  on  the  platinum 
wire.  The  end  of  the  wire  is  bent  into  a  loop  or 
ring  about  the  twelfth  part  of  an  inch  in  diameter. 
The  wire  is  then  heated  in  the  blow-pipe  flame,  and 
dipped  whilst  hot  into  the  borax  ;  the  portion  of 
borax  that  adheres  is  then  fused  on  to  the  wire  in 
the  blow-pipe  flame,  and  the  hot  wire  is  again 
dipped ;  this  is  repeated  until  the  loop  contains  a 
glass-like  bead  of  borax.  If  the  bead  has  become 
cloudy,  the  soot  causing  this  may  be  burnt  off  in 
the  oxidizing  point  of  the  flame.     Having  thus  ob- 


54 

tained  a  clear,  colorless,  transparent  bead,  the  next 
step  is  to  add  to  it  a  minute  portion  of  the  mineral 
which  is  to  be  tested.  By  touching  a  little  of  the 
finely  pulverized  mineral  with  the  borax  bead,  while 
softened  by  heat,  enough  will  adhere  to  the  bead  for 
a  first  trial.  The  bead  is  then  kept  at  a  white  heat 
in  the  oxidizing  point  of  the  flame  for  a  few  seconds, 
and  on  removal  its  color  is  noted,  both  whilst  hot 
and  when  cold.  If  no  color  is  imparted,  a  fresh 
trial  may  be  made  with  a  larger  quantity  of  the 
powder ;  but  if  the  bead  is  opaque  owing  to  the 
depth  of  color,  as  is  often  the  case,  a  fresh  experi- 
ment must  be  made,  using  a  still  smaller  quantity 
of  the  powder.  The  color  can  only  fairly  be  judged 
in  a  perfectly  transparent  bead.  If  no  color  can  be 
obtained  in  the  oxidizing  point,  further  experiment 
with  the  borax  bead  is  needless ;  but  if  a  color  is 
obtained,  it  is  then  advisable  to  try  the  effect  of  the 
reducing  flame  upon  the  same  bead.  The  following 
observations  and  inferences  may  result  from  this  test : 

COLOR   OF  BEAD   IN 

Oxidizing  Reducing  Presence  of 

Green  (hot);  blue  (cold)   .  .    .  Ked Copper. 

Blue  (hot  and  cold) Blue Cobalt. 

Amethyst Colorless Manganese. 

Green Green Chromium. 

Ked  or  yellow  (hot)  .    .    .    .  -» 

Yellow  or  colorless  (cold)..   }  bottle-green Iron. 

Violet    (hot)  ;    Red-brown 

(cold) Gray  and  turbid,  diffi- 
cult to  obtain  .    .    .  Nickel. 

This  mode  of  testing  may  often  be  used  to  prove 
the  presence  of  the  above-mentioned  metals. 


THE    BLOW-PIPE    AND    ITS   USES.  55 

It  requires  some  practice  before  reliable  results 
can  be  obtained  in  reducing.  The  reduced  bead,  if 
brought  out  of  the  flame  at  a  white  heat,  into  the 
air,  may  at  once  oxidize ;  but  this  may  be  prevented 
by  placing  it  inside  the  dark  inner  cone  of  an  ordi- 
nary candle  flame,  and  allowing  it  to  cool  partially 
there. 

Experiment  No.  2. — The  mode  of  testing  with  car- 
bonate of  .soda  on  charcoal,  is  performed  as  follows  : 
A  sound  piece  of  charcoal  half  an  inch  square  is 
chosen,  and  a  neat  cavity  is  scooped  out  on  its 
surface,  into  which  is  placed  a  mixture  containing 
the  pulverized  mineral  to  be  tested,  with  three  or 
four  parts  of  carbonate  of  soda,  the  whole  not  ex- 
ceeding the  bulk  of  a  pea.  After  lightly  pressing 
the  mixture  into  the  cavity,  the  blow-pipe  flame 
may  be  cautiously  applied  to  it ;  and  afterwards 
when  the  mixture  no  longer  shows  a  tendency  to 
fly  off,  the  charcoal  may  be  advanced  nearer  to  the 
blow-pipe,  and  finally  be  kept  at  as  high  a  tempera- 
ture as  possible,  in  the  reducing  part  of  the  flame. 

In  testing  for  tin  ore,  a  piece  of  cyanide  of  potas- 
sium, about  the  size  of  a  pea,  may  be  placed  upon 
the  mixture  after  the  first  application  of  heat,  and 
the  further  application  of  heat  may  then  be  con- 
tinued. 

This  treatment  is  designed  to  extract  metals  from 
minerals;  it  favors  in  the  highest  degree  the  re- 
moval of  oxygen.  But  like  the  borax  test,  it  is 
limited  in  its  application,  as  it  can  only  be  used  to 
detect  certain  metals.    The  failure  of  the  test  in  any 


56        prospector's  field-book  and  guide. 

case  must  not  be  looked  upon  as  a  conclusive  proof 
of  the  absence  of  the  particular  metal  sought ;  for 
instance,  copper  can  be  easily  extracted  from  car- 
bonate of  copper  by  this  test,  but  not  from  copper 
pyrites.  Still  the  test  is  a  most  valuable  and  indis- 
pensable one  to  the  mineralogist.  The  test  is  com- 
plete when  the  metal  is  obtained  as  a  globule,  in 
the  cavity  of  the  charcoal.  In  many  cases  the 
globule  will  be  found  surrounded  by  the  oxide  of 
the  metal,  forming  an  incrustation  on  the  charcoal ; 
and  the  color  of  such  incrustation  should  be  carefully 
noted,  both  at  the  moment  of  removal  from  the 
flame,  and  after  cooling.  By  pressing  the  globule 
between  smooth  and  hard  surfaces,  it  can  be  deter- 
mined whether  the  metal  is  flattened  out  (or  malle- 
able), or  crushed  to  pieces  (brittle). 

The  following  observations  and  inferences  may 
result  from  this  test : 

Globule  Incrustation  Presence  of 

Yellow,  malleable      ..  None Gold. 

White,  malleable    .    .  None Silver. 

Eed,  malleable    .    .    .  None Copper. 

White,  malleable   .    .  White Tin. 

White,  malleable   .    .  Red  (hot);  Yellow  (cold)  .  .    .  Lead. 

White,  brittle  ....  Red  (hot);  Yellow  (cold)  .  .    .  Bismuth. 

None Yellow  (hot) ;  White  (cold)  .  .  Zinc. 

White,  brittle,  giving 
off  fumes  when  re- 
moved the  the  flame.  White Antimony. 

Experiment  No.  3. — In  addition  to  these  substances 
there  are  others  which  occur  abundantly  in  minerals, 
and  which  may  be  recognized  by  the  blow-pipe  with 


THE   BLOW-PIPE    AND    ITS    USES.  57 

the  greatest  ease ;  for  instance,  sulphur  and  arsenic. 
These  may  be  discovered  by  heating  a  fragment  of 
the  mineral,  supported  on  a  piece  of  charcoal  or 
held  in  a  forceps  in  the  oxidizing  point  of  the 
flame,  and  comparing  the  odor  which  is  given  off. 
A  smell  of  burning  sulphur  indicates  that  the  min- 
eral contains  that  substance,  and  white  fumes  hav- 
ing a  garlic  odor  indicate  the  presence  of  arsenic. 

Mercury,  antimony,  and  other  substances  may 
escape  as  fumes  when  heated  in  this  manner. 

Nitrate  of  cobalt  dissolved  in  water,  and  used  in 
exceedingly  small  quantity,  helps  to  discriminate 
between  certain  white  minerals,  such  as  kaolin, 
meerschaum,  magnesite,  dolomite,  etc.  The  mineral 
is  reduced  to  powder  and  moistened  with  a  drop  of  a 
very  light  solution,  and  then  heated  before  the  oxid- 
izing flame  of  the  blow-pipe.  Kaolin  and  other  min- 
erals containing  alumina  assume  a  rich  blue  color, 
while  meerschaum  and  other  minerals  containing 
magnesia  become  flesh-colored.  Oxide  of  zinc, 
under  the  same  circumstances,  becomes  green,  and 
this  can  be  tried  with  the  white  coating  obtained 
on  charcoal  by  reducing  an  ore  of  zinc  with  car- 
bonate of  soda. 

Tests  in  glass  tubes  can  be  better  made  over  a 
spirit  lamp,  so  as  to  avoid  the  deposit  of  soot  on  the 
glass,  but  they  can  also  be  made  with  the  blow-pipe 
flame,  provided  it  is  used  carefully,  avoiding  too 
sudden  a  heat,  which  would  break  or  fuse  the  glass. 
The  presence  of  water  in  minerals  will  be  detected 
in  this  way,  and  the  water  collects  in  small  drops  in 


the  cold  part  of  the  tube.  Some  minerals  contain- 
ing sulphur,  arsenic,  antimony,  tellurium  and  selen- 
ium often  give  a  characteristic  deposit. 

Minerals  containing  mercury  can  also  be  tested 
in  this  way,  as  by  adding  a  little  carbonate  of  soda, 
sometimes  with  cyanide  of  potassium,  a  sublimate 
of  metallic  mercury  will  be  formed  in  the  cold  part 
of  the  tube.  A  little  charcoal  should  be  added  to 
arsenical  minerals. 

Organic  combustible  minerals  generally  leave  a 
deposit  of  carbonaceous  matter  at  the  bottom  of  the 
tube,  and  the  volatile  hydrocarbons  condense  in  the 
cooler  part.  The  tube  should,  therefore,  always  be 
long  enough  to  allow  for  this  condensation..  Min- 
erals which  yield  a  characteristic  smell  will  be  best 
tested  in  this  way. 


CHAPTER  III. 


CRYSTALLOGRAPHY. 


The  forms  which  many  minerals  assume  always 
indicate  their  composition.  It  is,  therefore,  some- 
times a  great  help  to  the  prospector  to  become  ac- 
quainted with  the  subject  of  crystallography  so  far 
as  to  enable  him  to  determine  the  system  or  order 
to  which  a  crystal  belongs. 

We  shall  treat  of  the  subject  only  so  far  as  may 
be  of  practical  application  to  the  purposes  of  the 
prospector  in  the  search  for  the  useful  minerals. 

It  is  necessary  to  understand  that  nearly  all 
mineral  substances,  when  they  appear  in  the  crys- 
talline condition,  assume  a  characteristic  form  and 
do  not  trespass  upon  that  of  other  minerals.  Al- 
though, to  the  unaided  eye  and  unskilled  vision, 
this  assertion  may  appear  to  be  a  mistake  in  some 
few  cases,  it  appears  so  only  because  the  differences 
are  exceedingly  small. 

All  crystalline  forms  have  been  reduced  to  six 
classes  or  systems,  which  are  named  as  follows :  I. 
Isometric;  II.  Tetragonal;  III.  Hexagonal;  IV.  Or- 
thorhombic;  V.  Monoclinic ;  VI.  Triclinic. 

I.  Isometric  system.  The  principal  forms  of  this 
system  are  the  cube,  octahedron,  dodecahedron,  the 

(59) 


two  trisoctahedrons,  the  tetrahexahedron,  and  the 
hexoctahedron. 

The  cube  has  six  equal  and  square  sides,  as  in 
Fig.  13.  In  this  form  lines  drawn  from  the  centre 
of  each  face  to  the  face  opposite,  cross  each  other  at 
right  angles,  and  are  of  the  same  length. 

This  system  is  called  isometric,  that  is,  iso  equal, 
and  metric  measure,  because  these  axes  or  lines  are 
of  equal  length  and  at  right  angles  to  each  other. 
It  must,  however,  be  remembered  that  the  cube  is 
modified  in  some  minerals,  but  wherever  these  modi- 
fications take  place  the  original  form  of  the  cube 
may  always  be  traced.  Some  of  the  changes  may 
be  very  intricate,  and  these  especially  unusual  or  in- 
tricate forms  we  shall  not  notice.  The  usual  forms 
only  are  of  importance,  and  can  be  treated  of  in  so 
small  a  work  as  this. 

The  learner  should  take  a  potato  and  cut  as  per- 
fect a  cube  as  possible,  and  make  himself  acquainted 
with  the  common  variations  which  may  belong  to 
the  cube,  as  we  shall  show,  with- 
out changing  the  length  of  the 
axis,  and  always,  cutting  so  that 
the  axis  will  always  be  the  same 
or  of  equal  lengths. 

Fig.   13   is  the  cube  with  the 

three  axes  A  A',  B  B' ,  C  C.     If, 

with  your  knife,  you  slice  off  one 

edge  angle  from  A  to  C  and  from  A  to  C,  and  in 

like  manner  from  A  to  B'  and  from  A  to  B,  you  will 

have  a  four-sided  pyramid,  the  apex  of  which  will 


CRYSTALLOGRAPHY. 


61 


be  at  A  and  the  four-sided  base  at  C  Bf ,  C  B,  or 
around  one-half  the  cube.  Now,  treat  the  opposite 
side  in  the  same  way,  and  you  will  then  have  the 
following  figure,  which  is  the  octahedron  (Fig.  14). 
The  dodecahedron  (12  sides),  Fig.  15,  may  be 
formed  by  taking  off  the  solid  angles  A,  B,  B',  A' '. 
In  all  three  cases  and  many  others,  the  three  axes 
remain  the  same  in  length  and  in  their  angular 
direction  where  the  forms  have  not  been  distorted. 


Fig.  15. 


A' 

The  Octahedron. 


The  Dodecahedron. 


II.  Tetragonal  system.  The  chief  forms  of  this 
system  are  the  two  square  prisms  and  pyramids, 
and  the  eight-sided  prism  and  double  eight-sided 
pyramid. 

The  tetragonal  system  has  also  three  axes  as  in 
the  isometric,  and  they  are  at  right  angles  to  each 
other,  but  the  vertical  axis  is  longer  than  the  others, 
as  in  Fig.  16. 

The  term  tetragonal  means  "  four-cornered  or  an- 
gled," and  is  not  precise,  for  a  cube  is  tetragonal, 
but  it  is  used  to  express  this  form  because  it  is  one 
word ;  otherwise  "  square  prismatic "  would  be  a 
more  correct  description,  since  Fig.  16  is  that  of  a 


62 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


prism ;  for  in  mineralogy  any  crystal  having  paral- 
lelograms for  sides  is  called  a  prism.  Cut  this 
prism  as  in  the  case  of  the  cube,  and  you  will  have 
the  form  seen  in  Fig.  17. 

Variations  upon  this  form  may  show  a  prism  with 
four-sided  termination  at  either  or  both  ends,  as  in 
Fig.  18.  This  is  the  form  of  the  transparent  gem 
called  the  zircon,  anciently  called  the  jacinth.  The 
zircon  has  been  mistaken  for  the  diamond,  which  it 
resembles  in  brilliancy,  and  somewhat  in  hardness. 
But  the  diamond  is  isometric  and  never  tetragonal, 


Fig.  16. 


Fig.  17. 


Fig.  18. 


^ 


Tetragonal  Prism.    Tetragonal  Octahedron.    The  Zircon. 


and  hence  it  may  be  distinguished  readily  from  the 
zircon. 

III.  Hexagonal  system.  The  chief  forms  of  this 
system  are  the  two  six-sided  prisms,  the  two  double 
six-sided  pyramids,  and  the  twelve-sided  prism  and 
double  twelve-sided  pyramid.  It  differs  from  the 
tetragonal  system  in  that  it  has  three  equal  lateral 
axes  instead  of  two  ;  the  vertical  being  at  right' 
angles,  as  in  Fig.  19,  with  each  of  the  three  lateral. 


CRYSTALLOGRAPHY. 


63 


But  it  must  be  remembered  that  owing  to  various 
causes  in  nature  the  hexagonal  crystal  always  calls 
for  hexagonal  terminations ;  thus  Figs.  20  and  21. 

Owing  to  various  causes  in  nature,  the  hexagonal 
crystal  may  be  found  under  various  modifications 
of  the  hexagonal  form,  but  it  can  always  be  reduced 
to  this  system.  The  symmetry  of  the  crystals  may 
be  by  sixes,  or  very  rarely,  by  cutting  each  angle 
it  may  be  in  twelves,  or  the  sides  may  be  unequal 
in  area  or  length,  as  in  Fig.  20.  The  author  once 
found  a  quartz  crystal  in  Switzerland  which  was,  for 


Fig.  19. 


Fig.  20. 


Fig.  21. 


V 


Hexagonal  Prism. 


Quartz-Crystals— Hexagonal. 


nearly  its  entire  length,  three-sided,  but  showed  its 
hexagonal  nature  only  at  the  extremity,  where,  hav- 
ing been  free  from  its  confinement  in  process  of  for- 
mation, it  had  assumed  its  normal  crystallization. 
As  has  been  said  in  another  place,  calcite  crystals 
sometimes  assume  a  hexagonal  prism  precisely  as 
does  quartz,  but  the  latter  shows  always  six-sided 
terminations,  whereas  lime  or  calcite  crystals  show 
three-sided  terminations,  as  in  Figs.  22  and  23. 
There  are  two  sections  or  forms  of  this  system,  the 
hexagonal  and  the  rhombohedral ;  both  belonging  to 


64 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


the  hexagonal  system,  and  distinguished  as  we  have 
shown. 

These  calcite  crystals  belong  to  the  rhombohedral 
section  of  the  hexagonal  system,  showing  rhombo- 
hedral forms  at  the  end,  as  in  Fig.  17. 


Fig.  22. 


r<2> 


Fig.  23. 


Calotte  hexagonal  crystal— three-sided 
termination.    Side  view. 


The  same— end  view. 


IV.  Orthorhombic  system.  The  characteristic 
forms  of  this  system  are  the  rhombic  prism  and 
pyramid.    There  are  also  other  forms  called  domes. 


Ftg. 

24. 

i^i, 

(S 

i  | 

!  '■■■.. 
oTi 

:...b 

1     • 

i  t 

i"  -,,J 

7> 

In  this  system  the  three  axes  are  unequal  and  in- 
tersect at  right  angles,  as  in  Fig.  24,  wherein  the 
axes,  A,  B,  C,  are  unequal  in  length,  but  at  right 


CRYSTALLOGRAPHY.  65 

angles  at  the  intersection.  The  terminations  are 
flat  although  frequently  beveled  on  the  surrounding 
edges. 

V.  Monoclinic  system.  The  monoclinic  forms 
are  too  difficult  to  be  fully  described  here,  but  it  is 
not  hard  to  learn  what  is  most  essential  about  them. 
In  this  system  two  of  the  axial  intersections  are  at 
right  angles ;  but  one  is  oblique,  and  the  side  of 
the  crystal  is  inclined  as  in  Fig.  25. 

Crystals  of  feldspar  in  general  which  contain  pot- 
ash (called  orthoclase  or  potash  feldspar),  are  mono- 
clinic, but  the  soda  feldspar  crystals  belong  to  the 
next  or  sixth  system,  as  do  also  the  lime  feldspars. 

VI.  Triclinic  or  "  thrice  inclined "  system.  In 
this  system  the  planes  are  referred  to  three  unequal 
axes  all  oblique  to  each  other.  The  only  import- 
ant feature  in  this  system  is  that  there  is  no  right 
angle  in  any  of  its  crystals  ;  but  it  is  of  little  use  for 
our  purposes,  since  with  the  exception  of  the  lime 
feldspar  and  soda-lime  feldspars  (anorthite  or  lime 
feldspar,  labradorite  or  soda-lime  feldspars,  andesitej 
and  oligoclase,  both  soda-lime  feldspars,  and  albite, 
a  soda  feldspar \  all  the  rest  are  of  little  importance,, 
except  microcline,  a,  potash  feldspar:. 

As-  illustrations  03  these  systems  the  follow- 
ing may  be  stated  :: 

Of  the  isometric  system,  or  first  system,  are  gold, 
silver,  platinum,  amalgam,  copper,  the  diamond, 
garnet,  magnetite,  pyrite>  galena,  alum,  kalinite,  all 
of  which  assume  the  cubic  octahedral,  or  some  allied, 
form. 

5 


Of  the  tetragonal,  or  second  system,  are  the  zir- 
con, chalcopyrite,  cassiterite  (tin  ore),  titanic  oxide, 
and  others. 

Of  the  hexagonal,  or  third  system,  are  beryl, 
aquamarine,  the  emerald,  chrysoberyl,  apatite  (lime- 
phosphate),  quartz. 

Of  the  orthorhombic,  or  fourth  system,  are 
barite  or  sulphate  of  barytes,  celestite  or  sulphate 
of  strontia,  and  carbonate  of  strontia,  also  cerussite 
or  lead  carbonate. 

Of  the  monoclinic,  or  fifth  system,  are  borax, 
gypsum,  glauber  salt  (mirabilite  is  its  mineralogical 
name),  copperas  (or  melanterite). 

Of  the  sixth  system  we  have  already  given  suffi- 
cient illustrations. 

Of  the  gems  not  mentioned  in  the  above,  the  tur- 
quois  owes  its  blue  to  copper,  and  is  never  crystal- 
lized, being  in  reniform  or  stalactitic  conditions.  It 
is  a  phosphate  of  alumina  with  water  in  composi- 
tion. This  mineral  or  gem  should  be  carefully 
distinguished  from  lazulite,  which,  though  blue, 
crystallizes  in  the  monoclinic,  or  fifth  system  ;  it  is  a 
softer  mineral  and  contains  considerable  magnesia, 
lime,  and  iron,  of  which  (except  a  very  small 
amount  of  iron),  the  true  turquois  contains  none. 
The  latter  is  the  gem,  and  may  be  beautifully  pol- 
ished, and  keeps  its  color,  which  is  due  to  copper. 
Lazulite  is  found  in  beautiful  crystals  at  Crowder's 
Mount,  in  Lincoln  Co.,  N.  C;  also  fifty  miles  north 
of  Augusta,  at  Graves's  Mount,  in  Lincoln  Co., 
Georgia. 


CRYSTALLOGRAPHY.  67 

Both  these  should  also  be  distinguished  from 
lapis  lazuli,  which  also  crystallizes,  but  in  the 
isometric  or  first  system,  though  commonly  massive 
and  compact.  This  is  valuable  in  the  arts,  and 
when  powdered  forms  the  ultramarine,  sl  rich  and 
durable  paint.  It  is  a  silicate  of  alumina,  but  con- 
tains some  lime  and  iron.  It  is  used  also  for  costly 
vases.  But  the  artifically  prepared  ultramarine  is 
largely  used  in  the  arts.  The  native  mineral  is 
found  in  syenite  and  in  metamorphic  crystalline 
limestone,  associated  with  pyrite  and  mica. 

The  topaz  crystallizes  in  the  orthorhombic  sec- 
tion of  the  hexagonal  or  fourth  system.  The  finest 
are  generally  in  prismatic  form,  showing  a  flat  plane 
at  the  extreme  end,  even  when  the  end  of  the 
crystal  has  several  inclined  faces.  It  is  a  silicate  of 
alumina  with  fluorine.  The  fluorine  may  be  de- 
tected before  the  blow-pipe  in  the  open  tube  by 
powdering  a  little  of  the  topaz  and  mixing  it  with  a 
little  microcosmic  salt  (a  salt  of  phosphorus).  The 
heat  of  the  blow-pipe  will  let  free  the  fluorine,  and 
its  strong  pungent  smell,  and  its  corrosion  of  the 
tube,  will  prove  its  presence.  With  the  cobalt 
(nitrate)  solution  on  charcoal,  it  gives  a  fine  blue 
color  in  proof  of  alumina.  This  is  the  best  test  of 
the  topaz,  as  the  color  of  the  mineral  is  not  always 
the  same,  nor  is  it  always  perfectly  transparent.  It 
is  found  at  Crowder's  Mount,  already  spoken  of,  and 
also  in  Thomas's  Mountains,  in  Utah,  near  lat.  39° 
40'  and  long.  113|°  W.  west  of  south  of  Salt  Lake 
(Dana).  In  Trumbull,  Conn.,  the  crystals  are 
abundant,  but  not  very  transparent. 


68        prospector's  field-book  and  guide. 

Meteoric  Iron  has  been  reported  from  North 
Carolina  as  found  native  in  a  partial  crystal  of  the 
isometric  form,  and  several  meteoric  masses  from 
Arizona  have  been  reported  at  the  Geological  Section 
at  Washington,  D.  C,  September,  1891,  as  contain- 
ing black  diamonds,  small  but  interesting. 

Meteorites  are  less  pure  than  native  iron,  the  iron 
in  them  being  almost  invariably  associated  with 
nickel,  and  they  also  contain  traces  of  cobalt,  cop- 
per and  other  metals.  In  the  many  specimens  ex- 
amined, the  iron  ranges  from  67  to  94  per  cent., 
and  the  nickel  from  6  to  24.  Their  masses  gener- 
ally range  from  a  few  pounds  in  weight  to  a  ton  or 
more.  If  cut,  and  the  surface  is  polished,  and  then 
acted  upon  by  nitric  acid,  a  kind  of  etching  action 
goes  on,  the  acid  acting  on  spaces  between  bands  of 
untouched  metal  which  cross  the  mass  in  two  or 
three  directions,  and  in  these  the  nickel  is  more 
abundant  than  in  other  parts,  for  it  is  not  equally 
diffused  in  the  alloy. 

Ruby  and  Sapphire.  These  crystallize  in  the 
rhombohedral  form. 

The  garnet  is  sometimes  mistaken  for  the  East 
Indian  ruby,  which  is  the  most  precious  variety, 
but  the  garnet  is  isometric,  and  even  when  cut  and 
mounted  may  be  distinguished  from  the  oriental 
ruby  by  the  superior  hardness  of  the  ruby,  the  latter 
being  next  to  the  diamond,  while  the  garnet  is  only 
as  hard  as  quartz,  or  not  quite  so  hard.  So  that  a 
garnet  of  the  most  precious  kind  if  worn  will,  under 
the  strong  lens,  show  the  lines  of  wear,  especially  on 


CRYSTALLOGRAPHY.  69 

the  edges,  which  are  absent  in  the  true  oriental 
ruby.  Oriental  garnets  are  frequently  confounded 
with  rubies  by  jewelers  in  Paris  as  well  as  in 
America.  For  instance,  some  years  ago,  two  oriental 
garnets  worth  about  $20  each  were  found  to  be  set 
in  a  diamond  ring  as  oriental  rubies,  for  which  the 
sum  of  $2,000  was  paid.  The  firm  in  Paris  ac- 
knowledged the  mistake,  and  refunded  the  $2,000. 
The  oriental  ruby  is  essentially  pure  alumina,  while 
the  oriental  or  precious  garnet  is  a  silicate  of  alum- 
ina with  lime  and  a  little  iron. 

All  these  gems  are  found  in  the  crystalline  rocks, 
as  granites,  gneiss,  dolomite,  and  some  (topaz,  ruby) 
associated  with  tourmaline,  tin  ores,  mica,  etc.,  and 
the  crystalline  lime-stones.  The  true  turquois  is 
found  in  Persia  in  the  clay  slates  in  veins  running 
in  every  direction.  Very  good  specimens  have  been 
found  in  Arizona  and  New  Mexico ;  also  in  Colo- 
rado in  the  Holy  Cross  Mining  district,  thirty  miles 
from  Leadville. 


CHAPTER   IV. 


SURVEYING. 


There  are  a  few  simple  measurements  which  are 
sometimes  desirable,  and  which  can  be  made  with- 
out the  labor  of  carrying  instruments  and  chains. 
The  actual  work  of  surveying,  to  be  of  any  value  to 
the  prospector,  must  be  so  accurately  performed  that 
the  work  should  be  entered  upon  as  a  specialty,  and 
he  must  use  a  theodolite  or  transit  and  make  use  of 
logarithms.  Any  small  work  on  surveying  or 
trigonometry  will  give  sufficient  information.* 

Some  few  measurements,  however,  and  simple 
surveys  with  easy  methods,  are  given  here  to  meet 
cases  where  only  a  general  approximation  is  re- 
quired. 

TO  MEASURE  HEIGHTS  WHICH  ARE  INACCESSIBLE. 

Any  height  of  tower,  stand-pipe,  tree,  etc.,  may  be 
measured  approximately  by  knowing  your  own 
height  and  taking  advantage  of  sunlight,  thus : 

Let  A  B,  Fig.  26,  be  the  height  of  the  object  to 

*For  this  purpose  we  would  recommend  the  following 
book:  The  Practical  Surveyor's  Guide.  By  Andrew  Duncan. 
A  new,  revised  and  greatly  enlarged  edition.  Illustrated 
by  72  engravings.  Philadelphia,  Henry  Carey  Baird  &  Co., 
1899.     Price,  $1.50. 

(70) 


SURVEYING.  71 

be  measured.  The  dotted  line  is  the  shadow  cast. 
Walk  off  into  the  sunlight  and  note  on  the  ground 
the  point  at  which  your  own  shadow  terminates ; 
measure  from  the  heel  to  that  point.  A  calculation 
in  single  "  rule  of  three  "  will  give  A  B  thus  : 

C"  B'  :  B'  A'  :  :  B  C  :  A  B. 

Heights  of  hills  or  land  may  be  nearly  enough 
measured  by  the  aneroid  barometer,  the  instructions 
in  the  use  of  which  go  with  the  instrument,  or  may 
be  obtained  with  it,  and  approximately  accurate 
aneroids  may  be  had  small  enough  to  go  into  the 
side  pocket,  or  still  more  accurate  ones  may  be 
easily  carried  in  a  case  held  by  a  small  strap  around 
the  shoulders.     For  hills  under  2000  feet,  the  fol- 

Fig.  26. 


~      jar 


B 


lowing  rule  will  give  a  very  close  approximation, 
and  is  easily  remembered,  because  55°,  the  assumed 
temperature,  agrees  with  55°,  the  significant  figures 
in  the  55,000  factor,  while  the  fractional  correction 
contains  two  fours. 

Observe  the  altitudes  and  also  the  temperatures 
on  the  Fahrenheit  thermometer,  at  top  and  bottom 


72        prospector's  field-book  and  guide. 

respectively  of  the  hill,  and  take  the  mean  between 
them.     Let  B  represent  the  mean  altitude  and  b  the 

B—b 

mean  temperature.     Then  5500  x  =  height 

B  -h  b 

of  the  hill  in  feet  for  the  temperature  of  55°.  Add 
^\q  of  this  result  for  every  degree  the  mean  temper- 
ature exceeds  55°;  or  subtract  as  much  for  every 
degree  below  55°. 

to  measure  areas. 

Theoretically,  it  is  very  easy  to  "  step  off  lines/' 
but  practically  it  is  very  difficult  thus  to  arrive  at 
accuracy  on  uneven  land.  But  where  one  is  ac- 
quainted wTith  the  exact  average  measurement  of 
his  step  on  level  land,  he  may  reach  some  approxi- 
mate accuracy  on  uneven  land  by  remembering 
that  in  ascending,  even  slightly,  his  average  de- 
creases, and  vice  versa  in  descending.  A  good  strong 
tape  measure,  kept  on  a  level  in  ascending  and  de- 
scending hills,  is  more  convenient  and  more  easily 
handled  than  a  chain. 

1.  On  square  areas  the  length  of  the  side  multi- 
plied into  that  of  the  adjacent  side  gives  the  area. 

2.  In  the  parallelogram,  where  all  angles  are 
right  angles,  the  same  is  true. 

3.  In  any  other  shapes  the  following  rules  are  to 
be  observed : 

First :  Measure  the  area  of  a  right-angled  tri- 
angle thus : 


SURVEYING. 


73 


iBi&.:27. 


Let  B,  Fig.  27,  be  the  right-angle  ;  the  aafca  of 
J.  .6  (7  is  equal  to  the  length, 
B  C,    multiplied    into   half 
the  perpendicular  distance, 
AB. 

Example:  # €  =  l$)fe; 
•therefore,  if  4  J5--='SK)  oft,, 
100  x  45  =  4500  sq.  ft.  = 
area  of  A  B  C. 

The  same  rule  applies 
when  the  triangle  is  not  a 

right-angled  triangle;  thus,  the  angle  at  A,  Fig.  28, 
being  obtuse. 

D  C=  150  ft.,  A  B  =  90  ft.;  multiply  150  ft.  by 

Fig.  28. 


one-half  A  B  =  45  ft.,  and  we  have  6750  sq.  ft.,  for 
i  CD  is  composed  of  two  right-angled  triangles, 
A  C  B  and  A  B  D,  as  in  the  previous  example. 

Or,  when  the  triangle  has  an  acute  angle  at  A, 
Fig.  29,  thus :  Treat  precisely  as  in  Fig.  28,  only 
letting  the  perpendicular  fall  from  D  upon  A  C, 
that  is,  invert  the  triangle. 

The  cases  wherein  the  sides  are  more  than  three 


74 


PROSPECTOR  S    FIELD-BOOK    AND   GUIDE. 


are  treated  by  resolving  all  such  areas  into  right- 
angled  triangles,  thus  : 

In  Fig.  30,  the  area,  A  C  D  B  may  be  resolved 
into  two  triangles,  A  C  B  and  C  D  B,  of  which  A  B 


Fig.  29. 


is  the  base  of  the  one  and  C  B  that  of  the  other. 
In  Fig.  31,  the  area,  A  C  D  B  E  K,  may  be  re- 
solved into  the  four  triangles,  AC  D,  A  D  B,  ABE 
and'  A  E  K.     The  perpendiculars  of  Fig.   30  are 


ED  and  C F.  Those  of  Fig.  31  are  C H,  IB, 
F  E,  and  K  G,  and  the  length  of  bases  may  be 
multiplied  into  half  that  of  the  perpendiculars,  as 
in  the  case  already  given,  and  the  feet  be  reduced 
to  acres,  rods,  etc.,  or  miles. 


SURVEYING. 


75 


For  the  number  of  square  feet  in  an  acre,  etc., 
see  Appendix  No.  3,  and  treat  it  thus :  Suppose  the 
area  of  Fig.  31  be  80,000  sq.  ft.,  then  according  to 


Table  No.  3,  it  will  be  1  acre,  3  roods,  13  poles,  25 
yards,  7  feet,  or  1.836  +  acre. 


TO    MEASURE    AN    INACCESSIBLE    LINE. 

Suppose  we  desire  to  measure  the  distance  across 
a  river,  as  in  Fig.  32. 

We  want  to  find  the  distance  A  B.  Measure  a 
distance  of  about  100  ft.,  B  D,  at  right  angles  to 
A  B,  and  raise  a  pole  at  0,  about  half-way  from  B 
to  D.  Proceed  in  measuring  at  right  angles  to  B  D, 
in  the  direction  D  E,  letting  E  be  that  point  at 
which  the  line  C  E,  if  extended,  would  strike  A. 
Now  you  have  two  right-angled  triangles  of  the 
same  angles,  for,  as  every  triangle  has  two  right- 


76         prospector's  FlELD-BOOK  and  guide. 

angles  according  to  geometry,  and  each  of  these  tri- 
angles has  one  right  angle,  and  the  opposite  angles 
at  C  are  equal  according  to  geometry,  the  remaining 

Fig.  32. 


C 


D 


angles  at  A  and  E  are  equal,  and  the  triangles  are 
proportional,  and  the  proportion  is — 

C  D  :  D  E  :  :  C  B  :  A  B. 

Then,  if  C  D  =  40  ft.,  D  E  =  45  ft.,  and  C  B  =  60, 
we  know  that  45  x  60  =  2700  divided  by  (C  D)  40 
ft.  =  67 J  ft.;  this  is  for  A  B,  or  the  distance  across 
the  river. 

The  only  difficulty  is  in  measuring  your  angles 
as  true  right  angles,  and  this  may  be  done  by 
measuring  the  perpendicular,  thus — 

Extend  the  line  A  B,  Fig.  32,  to  F,  Fig.  33,  and 
likewise  the  line  D  E,  Fig.  32,  to  C,  as  in  Fig.  33. 
Now  measure  equal  distances  on  the  line  B  D,  for 
the  lines  or  offsets,  B  C  and  B  H;  also  from  D  C, 


SURVEYING. 


77 


the  offsets  D  I  and  D  K ;  drive  sticks  in  at  G,  H,  I, 
and  K.  See  that  the  distances  represented  by  the 
dotted  lines  are  equal,  and  if  so,  the  lines  A  B  F 
and  D  C  are  perpendicular  to  the  line  G  K,  and 


Fig.  33. 


\ 


\ 


H 


\ 


your  work  will  be  well  done  and  very  nearly  ac- 
curate. 

It  is,  however,  well  for  the  prospector  to  use  a 
prism  compass  which  will  read  to  one-quarter  de- 
gree. Such  a  compass  may  be  had  at  very  low 
rate,  not  more  than  three  inches  diameter,  of  light 
weight  and  of  sufficient  accuracy.  The  author  has 
used  one  for  many  years,  and  traveled  with  it  many 
thousands  of  miles  in  Asia  and  Africa,  and  can 
testify  to  the  fact  that  by  customary  use  it  may  be 
handled  to  a  great  degree  of  accuracy  for  horizontal 
angles.  The  needle  is  attached  to  the  under  side 
of  a  cord  with  steel  engraved  degrees  and  fractions, 
and  read  by  a  magnifying  prism. 

In  almost  every  conceivable  surveying  project, 
especially  in  running  adits  and  sinking  shafts  to 


78        pkospector's  field-book  and  guide. 

strike  adits  and  galleries,  only  the  best  instruments 
should  be  used.  Everything  depends  upon  the 
most  accurate  measurements,  and  this  department 
of  engineering  is  not  one  that  can  be  treated  ap- 
proximately, because  any  error  in  measurement 
may  result  in  very  provoking  and  expensive  mis- 
takes. 

We  have  presented  all  that  is  required  on  surface 
measurements,  except  where  it  becomes  necessary 
to  make  such  accurate  proceedings  as  may  only  be 
executed  by  use  of  the  finest  instruments,  and  that 
with  considerable  practice.  Otherwise  accurate 
mathematical  tables  are  of  little  importance,  as 
their  use  is  based  upon  the  presence  of  most  ac- 
curate data,  and  without  this  the  best  methods  and 
diagrams  are  in  vain. 

This  subject  of  mining  engineering  does  not  come 
within  the  range  of  our  work,  and  for  all  mere  ex- 
ploring as  a  prospector  such  ground-work  or  digging 
for  examination  as  is  necessary  will  readily  suggest 
itself  to  any  intelligent  workman. 


CHAPTER  V.  * 

ANALYSES    OF    ORES. 

I.   Wet  Method. 

Preliminary  examinations  may  be  made  at 
first  with  the  pocket  lens  and  a  piece  of  steel  or  a 
heavy-bladed  pocket-knife.  The  first,  to  see  if  any 
native  metals  or  any  sulphides,  etc.,  are  present ; 
the  second,  to  try  the  softness  or  silicious  nature 
of  the  mineral ;  if  much  quartz  (silex)  is  present  it 
will  strike  fire. 

Pulverize  a  small  part  and  use  the  blow-pipe  to 
detect  sulphur,  arsenic,  selenium,  by  the  smell 
on  charcoal  or  in  the  glass  tube.  Arsenic  fumes 
have  a  garlic  odor,  silenium  that  of  horse-radish. 

Use  a  test-tube  with  a  little  nitric  acid  and  heat 
over  a  spirit  flame.  Add  a  few  drops  of  water  and 
one  drop  of  sulphocyanide  of  potash — an  intense 
deep  red  appears,  deeper  according  to  amount  of 
iron  and  solvency  of  the  mineral  in  nitric  acid. 

Try  another  portion  in  the  same  way,  but  drop 
one  drop  of  hydrochloric  acid.  A  dense  curdy 
white  precipitate  indicates  silver. 

Native  gold  or  silver  is  determined  by  color  and 
softness,  as  we  have  elsewhere  stated  (see  Index). 
Treat  another  portion  in  the  same  way  with  nitric 

(79) 


80        prospector's  field-book  and  guide. 

acid,    drop   in   several   drops    of  strong   ammonia 
water.     The  blue  color  indicates  copper. 

Antimony  and  tin  are  detected  by  the  blow-pipe. 
Place  the  former  upon  charcoal  with  carbonate  of 
soda,  and  brilliant  metallic  globules  are  obtained ; 
the  metal  fumes  and  volatilizes,  and  covers  the 
charcoal  with  white  incrustations,  and  needle- 
shaped  crystals  appear.  Tin  appears  when  the  ore 
is  mixed  with  carbonate  of  soda  and  cyanide  of 
potassium  on  charcoal,  and  the  inner  flame  turned 
on — ductile  grains  of  metallic  tin  and  no  incrusta- 
tions appear. 

Manganese  gives  amethystine  beads  of  borax  in 
the  outer  flame,  0  F,  disappears  with  the  inner, 
I F,  reappears  with  the  0  F. 

Alumina,  magnesia,  lime,  give  their  characteristic 
colors,  or  in  the  last  case,  incandescent  light  before 
the  blow-pipe  on  charcoal.  Alumina  heated  on 
charcoal,  and  then  touched  by  a  half  drop  of  proto- 
nitrate  of  cobalt,  then  heated  strongly  in  the  0 
flame,  gives  a  blue  color.  Magnesia  so  treated  gives 
a  faint  red  or  pink,  seen  just  as  it  cools. 

Zinc  heated  on  charcoal  with  carbonate  of  soda 
in  the  reducing  flame  becomes  metallic,  and  when 
oxidizing  in  the  0  flame  gives  a  white  oxide  which 
is  yellow  when  hot,  white  when  cooled,  and  with 
protonitrate  of  cobalt  when  heated  in  the  0  flame,  & 
beautiful  characteristic  green  color. 

Cobalt  and  nickel  give  the  colors  we  have  noticed 
in  another  place  under  their  respective  names  (set, 
Index)., 


ANALYSES    OF    ORES.  81 

Uranium  heated  with  microcosmic  salt  (phosphate 
of  soda  and  ammonia),  on  platinum  wire  in  the  0 
flame  dissolves,  producing  a  clear  yellow  glass, 
which,  on  cooling,  becomes  yellowish-green.  But 
the  analyst  should  remember  that  copper  also  pro- 
duces a  green  bead,  but  only  in  the  outer  or  oxidiz- 
ing flame,  and  chromium  the  same,  but  in  both 
outer  and  inner  flames. 

The  copper  green  becomes  blue  on  cooling,  the 
chromium  green  remains  green  on  cooling.  This 
will  always  prove  the  metal. 

Titanium  in  the  presence  of  peroxide  of  iron,  as 
in  some  titanic  ores  of  iron  and  sand,  gives,  with 
microcosmic  salt  in  a  strong  reducing  blow-pipe 
flame,  a  yellow  glass,  which  on  cooling  becomes  red. 

Mercury  may  be  detected  in  almost  any  of  its  ores 
by  the  process  described  {see  Index),  by  heating  in  a 
glass  tube  and  noting,  under  the  lens,  the  sublima- 
tion of  mercury  in  very  minute  shining  particles. 

Minerals  which  are  carbonates  may  be  detected  by 
their  effervescence  when  touched  by  a  drop  of  hydro- 
chloric acid,  as  in  limestone  and  spathic  iron  ore. 
But  the  analyst  must  remember  that  some  cyanides 
effervesce  where  neither  lime  nor  carbonic  acid  is 
present,  and  chloride  of  lime  where  there  is  no  car- 
bonic acid.  With  these  latter  other  tests  must  be 
used,  but  the  sense  of  smell  will  show  that,  carbonic 
acid  does  not  exist,  the  latter  having  no  odor. 

Some  sandstones  have  a  small  amount  of  lime 
carbonate  and  must  be  tried  under  the  lens,  as  the 
bubbles  are  minute.     But,  while  in  these  examina- 
6 


82 

tions  great  help  is  received,  and  many  determina- 
tions made,  especially  in  simple  minerals  and  ores, 
there  are  compound  ores  so  mixed  in  elements  that 
the  above  tests  fail  to  give  satisfaction,  because  the 
colors  are  mixed  and  the  action  confused.  Some 
of  the  elements  must  be  moved  out  of  the  associa- 
tion and  a  separation  made.  This  analysis  is  called 
qualitative,  and  we  shall  take  a  case  of  very  full 
analysis  of  a  compound  ore. 

Qualitative  analysis  of  ores  where  many  ele- 
ments are  present : 

There  are  many  times  when  it  becomes  not  only 
a  matter  of  curiosity  but  of  importance  for  the 
prospector  to  know  the  entire  composition  of  the 
ore  he  has  before  him. 

With  a  little  practice  the  "  wet  method,"  as  it  is 
called,  may  be  used  by  the  prospector  with  all  the 
accuracy  required  under  the  circumstances. 

The  "  dry  method  "  of  analysis  is  that  in  which 
no  liquids  are  used,  but  only  fluxes  and  heat. 
Although  for  one  or  two  elements  it  is  simpler  than 
the  wet  method,  it  may  so  happen  that  sufficient 
heat  cannot  be  had.  We  shall,  therefore,  give 
some  directions  whereby  the  wet  method  may  prove 
of  greater  service. 

1.  Pulverize  the  ore  as  finely  as  possible  and 
sieve  it,  passing  the  entire  quantity  taken  as  an 
assay.  Should  any  part  be  left  remaining  in  the 
sieve  it  may  be  a  very  important  part.  Pass  the 
whole  through. 

2.  Take  a  test  tube  and  drop  a  little  of  the  sifted 


ANALYSES    OF    OKES.  83 

ore  into  it,  pour  a  little  nitric  acid  upon  it,  add 
about  one-eighth  part  water,  warm  it  gently  over  a 
spirit  flame  to  see  if  it  will  dissolve;  if  not,  then  add 
four  times  as  much  in  bulk  of  muriatic  acid  (hydro- 
chloric acid).  If  this  will  not  dissolve  then  proceed 
as  follows : 

3.  Put  the  assay,  after  fine  pulverization,  into  a 
platinum  crucible.  Place  it  in  a  suitably  arranged 
platinum  wire  triangle  so  that  it  will  hang  over  an 
alcoholic  blast  lamp.  When  all  is  ready  add  a 
mixture  of  equal  parts  of  sodium  carbonate  and  of 
potassium  carbonate,  amounting  in  all  to  about  four 
times  the  bulk  of  the  assay,  stir  gently  with  a  glass 
rod  or  a  stiff  platinum  wire,  and  then  light  the 
lamp.  Watch  the  assay,  and  when  it  begins  to 
swell  up  withdraw  the  lamp,  but  return  it  when  the 
swelling  subsides,  so  that  the  alkalies  do  not  throw 
your  assay  out  of  the  crucible,  which  should  be  only 
one-half  full  at  the  beginning.  With  care  the  con- 
tents will  soon  subside,  and  under  increased  heat 
become  a  quiet  liquid  mass.  Now,  extinguish  the 
flame,  cool  the  crucible,  remove  crucible  contents  to 
a  beaker  glass  or  place  the  crucible  with  its  con- 
tents within  the  beaker,  and  pour  a  little  water 
upon  it,  add  some  nitric  acid,  or  a  little  hydrochloric 
acid,  but  not  the  two  acids  together,  unless  you  have 
only  the  assay  and  not  the  platinum  crucible  in 
the  beaker — nitro-muriatic  acid  dissolves  platinum. 
Warm  and  stir  till  the  assay  is  entirely  dissolved, 
except  perhaps  some  white  grains  of  silex. 

4.  If  the  preceding  work  has  been  properly  per- 


84 

formed,  the  assay  is  now  dissolved  and  you  are 
ready  for  work.  Filter  the  contents  of  the  beaker 
to  separate  any  undissolved  remainder,  if  any  such 
is  seen  in  the  glass,  and  wash  the  filter-paper  by 
passing  an  ounce  or  two  of  water  through  it,  and 
now  make  preparations  for  the  next  step.  It  is  not 
necessary,  where  extreme  accuracy  is  not  required, 
to  wash  the  filter-paper  perfectly  free  from  the  acids. 
But  if  it  be  necessary,  then  furnish  yourself  with  a 
small  strip  of  platinum  ribbon ;  clean  its  surface  to 
a  polish.  If  a  drop  of  the  filtrate  evaporated  from 
this  surface  shows  not  the  least  trace  of  sediment  or 
outline  even  under  a  lens,  the  filter-paper  is  suffi- 
ciently washed.  When  the  filter-paper  is  to  be 
burned  and  weighed,  it  must  be  perfectly  freed  from 
the  acids  by  continuous  washing. 

5.  Pour  ten  or  fifteen  drops  of  the  filtrate  into  a 
test  tube.  Drop  in  three  or  four  drops  of  hydro- 
chloric acid.  If  a  precipitate  forms  it  may  be  of 
silver  ;  if  so,  it  will  grow  dark  violet  on  exposure 
to  daylight,  or  more  rapidly  and  darker  in  sunlight. 
Or  to  test  more  quickly,  add  strong  ammonia,  30  to 
40  drops  ;  it  dissolves  after  a  short  time  ;  or  if  it  does 
not  dissolve,  then  it  is  lead  ;  filter  and  test  on 
charcoal  with  the  blow-pipe ;  if  it  gives,  with  inner 
flame,  a  bead  and  yellow  incrustation  around,  it  is 
lead.  Or,  if  none  of  the  above  results  are  seen,  and 
yet  there  is  a  precipitate,  then  it  is  mercury.  To 
prove  this,  add  a  solution  of  carbonate  of  potash  and 
digest ;  it  turns  black ;  filter  and  place  it  in  a  glass 
tube,  heat  gently  with  a  blow-pipe ;  it  volatilizes 


ANALYSES    OF    ORES.  85 

and  condenses  on  the  sides;  examine  with  strong 
lens,  it  is  mercury. 

6.  But  suppose  hydrochloric  acid  produces  no 
precipitate  though  in  excess  and  heated?  Then 
there  is  neither  lead,  silver  nor  mercury  in  the 
assay,  and  it  is  not  necessary  to  treat  the  ore  for 
either,  but  proceed  to  the  next  step.  It  will  be  seen 
why  we  directed  nitric  acid  to  be  poured  on  the 
assay,  as  in  No.  2.  Hydrochloric  acid  would  have 
prevented  these  tests  as  given,  but  you  are  now 
prepared  for  the  next  metals,  with  three  less  to  look 
for,  or  with  a  certainty  as  to  the  presence  of  one  or 
more  of  the  three. 

7.  The  whole  assay,  or  its  solution,  may  now  be 
used.  If  any  precipitate  occurred  in  the  test-tube, 
treat  the  whole  assay  solution  with  hydrochloric 
acid,  heat  to  boiling,  and  separate  the  precipitated 
metal  or  metals  in  the  whole,  as  in  the  test-tube,  by 
nitration.  Wash,  set  the  paper  (filter)  aside  under 
cover  of  paper  to  dry,  and  pass  hydrogen  sulphide 
slowly  through  the  filtrate  until  the  filtrate  smells 
plainly  of  the  gas. 

8.  As  this  gas  is  frequently  used,  make  a  simple 
and  cheap  apparatus  so  that  you  may  have  a  supply 
at  any  time,  thus  :  Cut  off  the  bottom  of  a  long- 
bottle  *  of  small  diameter,  D,  say  about  two  inches, 
and  fit  it  into  a  fruit  jar,  E,  as  in  Fig.  34. 

*  Cut  a  nick,  with  a  large  file,  in  the  spot  where  you  wish  to  start 
a  crack  near  the  bottom,  then  heat  a  rod.  or  poker,  or  spike-nail, 
nearly  red-hot,  place  it  on  the  nick,  a  crack  starts;  draw  your  hot 
iron  and  the  crack  will  follow;  when  nearly  cracked  around  pull  the 
bottom  off.  A  glass  chimney  may  be  used,  but  it  is  rather  too  small 
to  contain  sufficient  iron  sulphide. 


86 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


The  top  A  should  be  fitted  loosely  so  that  it  may 
be  removed  and  let  air  pass  through.  The  cork  at 
B  must  be  air-tight.  Fit  a  small  tube  into  the  cork 
after  bending  it  in  a  spirit-lamp  flame — a  quarter- 
inch  tube  with  an  eighth-inch  aperture  is  suffi- 
ciently large  and  is  easily  bent.  Take  an  inch  rod 
of  iron,  let  the  blacksmith  heat  it  white-hot,  and 
press  it  into  a  small  roll  of  brimstone,  this  will  give 
you  iron  sulphide — you  need  it  in  pieces  as  large 

Fig.  34. 


as  bullets :  it  melts  readily  against  the  brimstone. 
Place  some  cotton  in  the  neck  of  the  bottle,  and 
having  fitted  a  plug  of  wood  with  holes  in  it  for  the 
bottom  of  the  bottle,  invert  the  bottle  and  fill  it 
half  full  of  iron  sulphide  lumps,  fasten  the  wooden 
plug  in  the  bottom,  not  very  tightly,  but  tightly  in 
three  or  four  places,  so  that  water  can  pass  easily, 
and  yet  the  plug  be  well  fixed  in.  Put  the  bottle 
in  its  place,  resting  in  the  jar  at  A,  and  somewhat 
loosely  fastened.  But  this  must  be  after  you  have 
half  filled  the  jar  with  a  mixture  of  equal  parts  of 


ANALYSES    OF    ORES.  87 

common  hydrochloric  acid  and  rain-water  (or,  next 
best,  well-water).  Hydrogen  sulphide  will  form 
immediately,  and  if  you  have  made  all  connections 
perfectly,  as  in  the  figure,  the  gas  will  pass  from 
this  apparatus  into  the  solution  of  ore  in  the  beaker 
and  precipitation  will  soon  take  place.  The  advan- 
tage of  this  apparatus  is  that  if  you  tie  two  little 
blocks  of  wood  against  the  sides  of  the  India-rubber 
tubes,  C  C,  so  as  to  press  the  sides  together  and  stop 
the  gas  from  flowing,  the  gas  forming  pushes  the 
water  out  of  the  interior  glass  D,  and  the  gas  stops 
forming,  but  is  ready  at  any  moment  to  begin  as 
soon  as  the  string  around  the  little  blocks  is  removed. 

9.  After  introducing  the  hydrogen  sulphide  until 
the  filtrate  smells  of  the  gas,  filter  and  wash  the  pre- 
cipitate, mark  the  paper  containing  it  with  the 
letter  A,  and  put  this  precipitate  aside  for  the 
present.  This  is  the  precipitate  from  the  hydrogen 
sulphide. 

10.  The  filtrate.  If  the  strip  of  platinum 
shows  that  it  contains  some  material  after  evapora- 
tion of  a  few  drops,  proceed  by  adding  a  solution  of 
ammonium  chloride  (sal  ammoniac),  and  then  aqua 
ammonia  to  the  filtrate,  using  about  one-fifteenth 
or  one-twentieth  of  the  bulk.  Then  add  ammo- 
nium sulphide  so  long  as  any  precipitate  is  appar- 
ent. Let  it  stand  awhile.  This  precipitate  may 
contain  alumina,  chromium  oxide,  zinc,  nickel, 
manganese,  cobalt  and  iron  as  sulphides.  It  may 
likewise  contain  phosphates,  borates,  oxalates,  and 
hydrofluorates  of  the  alkaline  earths  (barium,  stron- 
tium and  lime).     The  latter  we  may  not  care  for. 


05  PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 

11.  Filter  and  wash  this  precipitate.  Add  a  little 
water  to  the  hydrochloric  acid,  now  to  be  used  in 
treating  this  precipitate.  Add  this  diluted  hydro- 
chloric acid  in  sufficient  quantity  to  dissolve  the 
precipitate,  and  put  it  aside  to  digest.  If  any  part 
refuses  to  dissolve,  it  is  because  there  may  be 
present  cobalt,  or  nickel,  or  both  ;  add  nitric  acid 
and  boil,  for  these  metals  dissolve  in  hot  nitro- 
hydrochloric  acid.  Filter.  Next  add  to  the  whole 
solution  ammonium  chloride,  and  excess  of  aqua 
ammonia.  The  consequent  precipitate  may  contain 
alumina,  chromium  oxide,  sesquioxide  of  iron,  and 
the  alkaline  earths,  as  phosphates,  etc.  Dissolve 
the  precipitate  by  digesting  in  caustic  potash  solu- 
tion till  all  is  dissolved  that  will  dissolve.  Filter. 
The  solution  may  contain  alumina  and  chromium 
oxide ;  boil  for  some  time,  and  if  a  precipitate  is 
formed,  it  is  chromium  oxide  ;  confirm  by  the 
blow-pipe  ;  it  gives  a  green  bead  with  borax,  height- 
ened by  fusion  with  metallic  tin  or  charcoal,  which 
is  the  blow-pipe  test  for  chromium. 

12.  Now  super-saturate  the  solution  with  hydro- 
chloric acid  and  boil  with  excess  of  ammonia  ;*  if  a 
precipitate  is  formed  it  is  alumina.  Confirm  with 
blow-pipe,  as  has  been  shown.  What  was  dissolved 
by  digestion  with  potassium  hydroxide  (caustic 
potash  solution)  has  now  been  treated.  The  pre- 
cipitate  may    contain    iron    and    more    chromium 

*By  "excess"  is  meant  so  much  that  after  stirring  with  a  glass 
strip  or  rod,  the  liquid  smells  strongly  of  ammonia. 


ANALYSES    OF    ORES.  89 

oxide,   and   the   phosphates,   etc.,   of  the    alkaline 
earths. 

13.  We  will  now  proceed  with  a  portion  of  this 
precipitate  by  first  dissolving  it  in  as  small  a  quan- 
tity of  hydrochloric  acid  as  is  possible,  filter,  and 
add  to  the  solution  (made  as  nearly  neutral  as  pos- 
sible) two  or  three  drops  of  ferro-cyanide  of  potash 
(yellow  prussiate  of  potash  in  solution);  a  blue  pre- 
cipitate is  formed,  proving  the  presence  of  iron 
sesquioxide.  Wash  another  portion  and  fuse  it  in 
a  small  crucible  with  potassium  nitrate  (pure  salt- 
petre) and  sodium  carbonate  about  equal  parts. 
When  cold  digest  with  water ;  a  yellow  solution 
results,  which  produces  a  yellow  precipitate  with 
acetate  of  lead,  showing  the  presence  of  oxide  of 
chromium.  This  double  finding  of  chromium  oxide 
(for  it  was  found  before)  is  due  to  the  relative  quan- 
tity of  iron  present  as  related  to  chromium  oxide 
present,  which  will  not  be  entirely  precipitated 
at  one  time  in  the  presence  of  iron  under  these 
circumstances. 

14.  We  now  go  back  to  the  solution  filtered 
off  from  the  precipitate  treated  of  in  paragraph  11. 
This  solution  may  contain  zinc,  manganese,  nickel 
and  cobalt.  Digest  with  ammonium  sulphide,  wash 
the  consequent  precipitate  and  dissolve  it  in  nitro- 
hydrochloric  acid  (aqua  regia).  It  may  be  dis- 
solved upon  the  filter  by  dropping  the  mixed  acids 
and  filtering  through  into  a  clean  beaker,  just  as  it 
could  have  been  done  in  paragraph  11.  This  is 
convenient  when  the  precipitate  adheres  too  tightly 


90        prospector's  field-book  and  guide. 

to  the  filter  to  allow  of  scraping  it  off  entirely. 
Digest  this  clear  solution  with  potassium  hydroxide 
(or  caustic  potassa)  precisely  as  in  paragraph  11. 
This  potassa  may  be  put  into  the  beaker  in  small 
pieces  of  the  stick,  in  which  form  potassium  hy- 
droxide generally  is  sold. 

(a)  The  solution  may  contain  zinc  oxide. 

(6)  The  precipitate  may  contain  manganese,  cobalt 
and  nickel,  as  oxides.  Pass  hydrogen  sulphide 
through  the  solution  (a)  until  the  precipitate  (white 
zinc)  has  ceased  to  fall.  Wash  and  agitate  the  pre- 
cipitate (b)  with  a  solution  of  carbonate  of  ammonia. 
The  precipitate  which  now  falls  is  the  carbonate 
of  manganese — confirm  this  by  the  blow-pipe.  The 
solution  from  this  last  treatment  may  contain  cobalt 
and  nickel  oxides.  Evaporate  it  to  dryness,  redis- 
solve  in  a  few  drops  of  hydrochloric  acid,  and  again 
evaporate  to  a  moist  mass  and  divide  the  mass  into 
two  parts.  Heat  one  portion  with  borax  in  the 
blow-pipe  flame,  a  blue  bead  proves  cobalt.  Dis- 
solve the  other  portion  in  water  and  add  solution 
of  cyanide  of  potassium  slowly,  a  precipitate  is 
formed  which,  on  continued  adding  of  the  potas- 
sium cyanide,  begins  to  redissolve.  On  adding 
hydrochloric  acid  it  is  again  precipitated.  It  is 
nickel.     Confirm  with  the  blow-pipe. 

15.  In  paragraph  9,  paper  A  was  put  aside. 
This  paper  contained  the  precipitate  holding  the 
copper  of  the  ore  if  any  was  present.  Digest  this 
with  ammonium  sulphide  (or  potassium  sulphide). 
A  solution  and  a  precipitate  are  formed.     The  pre- 


ANALYSES    OF    ORES.  91 

cipitate  may  contain  lead,  mercury,  bismuth,  cad- 
mium, besides  copper,  as  sulphides.  The  solution 
may  contain  gold,  platinum,  antimony,  arsenic,  and 
tin  as  sulphides. 

16.  Treat  the  precipitate  first,  by  boiling  it  with 
nitric  acid.  A  black  or  brownish  residue  remains 
undissolved.  Take  a  hard  glass  tube,  and  having 
washed  and  dried  the  black  residue,  introduce  some 
of  it  into  the  tube  and  heat  it.  It  may  act  in  three 
ways :  (a)  it  sublimes  without  change;  mercury  oxide 
was  present — test  with  blow-pipe ;  (6)  it  sublimes 
leaving  a  white  powder  which,  when  moistened  with 
ammonium  sulphide,  turns  black,  proving  it  to  be 
lead  sulphate;  (c)  it  sublimes,  but  as  a  mixture  of 
mercury  sulphide  with  minute  globules  of  metallic 
mercury,  showing  that  through  some  haste  or  lack  of 
care,  mercury  as  sub-oxide  of  mercury  still  remains 
when  it  should  have  been  entirely  precipitated  as 
chloride  of  mercury  at  the  first  (paragraph  5). 

17.  We  now  proceed  with  the  nitrate  (obtained  as 
stated  in  paragraph  16),  from  the  black  or  brownish 
residue.  Treat  this  with  solution  of  carbonate  of 
potash  and  wash  the  consequent  precipitate,  and 
then  digest  this  precipitate  in  cyanide  of  potassium, 
in  excess,  while  it  is  moist.  This  may  be  done  on 
the  filter  after  changing  the  beaker,  since  this  fil- 
trate or  solution  must  be  kept.  The  insoluble  part 
may  contain  lead  and  bismuth  as  carbonates — the 
solution  may  contain  copper  and  cadmium  as  double 
salts  with  cyanide  of  potassium. 

18.  Proceed  with  the  insoluble  part  by  boiling  it 


92        prospector's  field-book  and  guide. 

with  dilute  hydrochloric  acid.  To  one  part  of  the 
resultant  solution  add  sulphuric  acid;  the  precipitate 
indicates  lead.  To  the  other  part,  after  concentra- 
tion by  evaporation,  add  a  large  quantity  of  water 
— a  milkiness  is  produced  indicating  bismuth. 

19.  Into  the  solution  (paragraph  17),  after  digest- 
ing with  potassium  cyanide,  pass  hydrogen  sulphide 
— the  precipitate,  if  formed,  indicates  cadmium — test 
it  with  the  blow-pipe.  To  the  solution  add  hydro- 
chloric acid — copper  sulphide  will  be  precipitated  ; 
add  a  few  drops  of  nitric  acid,  which  will  dissolve 
the  copper  sulphide,  and  then  by  adding  ammonia 
in  slight  excess  the  solution  has  a  blue  color  indicat- 
ing copper. 

20.  We  are  now  to  treat  the  solution  mentioned  in 
paragraph  15.  The  insoluble  part,  paragraph  16, 
having  been  separated  off  as  there  stated,  add  to  the 
solution  acetic  acid,  and  boil.  If  a  precipitate  be 
produced,  collect  a  small  portion,  wash  and  heat  it 
over  a  spirit-lamp  upon  a  strip  of  platinum  foil.  If 
it  burns  with  a  bluish  flame  and  leaves  no  residue 
whatever,  it  is  sulphur  and  nothing  more  may  be 
done — this  part  of  the  assay  is  exhausted.  But  if  it 
leaves  some  residue,  then  several  important  elements 
may  be  present.  Proceed,  and  to  one  part  add  a 
solution  of  chloride  of  tin  (protochloride  with  a 
drop  of  nitric  acid  added),  a  purple  color  is  pro- 
duced. To  another  part  add  a  solution  of  proto- 
sulphate  of  iron — a  brown  precipitate  is  produced 
indicating  gold  in  both  cases. 

To  another  part  add  ammonium  chloride  (solu- 


ANALYSES    OF    OKES.  93 

tion),  a  yellow  crystalline  precipitate  falls  which 
marks  platinum.  Arsenic  may  be  tested  by  the 
blow-pipe  in  the  ore,  but  if  the  presence  of  sulphur, 
in  larger  quantity,  prevents  detecting  a  small  quan- 
tity of  arsenic,  it  may  be  detected  thus :  Take  a  part 
of  the  black  or  brownish  precipitate  resulting  from 
the  addition  of  acetic  acid,  and  mix  it  with  three 
times  its  bulk  of  nitrate  of  potash  (saltpetre)  and 
carbonate  of  soda.  Project  this  mixture,  a  little  at 
a  time,  into  a  Berlin  crucible,  in  which  a  mixture 
of  the  same  substances  has  been  placed  and  is  in 
fusion  over  a  lamp.  At  conclusion,  digest  the  fused 
mass  with  pure  water ;  filter ;  add  excess  of  nitric 
acid  and  heat ;  now  add  nitrate  of  silver;  filter  when 
cold,  and  add  very  dilute  ammonia;  a  brown  pre- 
cipitation or  coloring  marks  arsenic. 

Dissolve  another  portion  of  the  dark  precipitate 
or  residue  from  acetic  acid  in  hydrochloric  acid. 
Place  in  the  solution  a  strip  of  metallic  zinc — a 
pulverulent  deposit  takes  place  on  the  zinc,  indi- 
cating antimony.  If  more  proof  be  wanted  remove 
the  powder  to  a  beaker  and  digest  in  nitric  acid, 
when  a  white  precipitate  is  formed.  Digest  it  with 
a  strong  solution  of  tartaric  acid,  only  a  part  may 
be  dissolved,  but  filter;  into  the  clear  solution  pass 
hydrogen  sulphide  and  an  orange-colored  precipi- 
tate is  formed,  proving  antimony. 

In  the  last  paragraph  it  was  found  that  a  part  of 
the  precipitate  was  not  dissolved  in  the  tartaric 
acid  ;  dry  it ;  place  it  on  charcoal  with  a  little 
cyanide  of  potassium  and  carbonate  of  soda,  and 


94 

turn  the  inner  flame  of  the  blow-pipe  upon  it ;  it  is 
reduced  to  metallic  tin. 

In  the  above  analysis  provision  has  been  made 
for  the  detection  of  sixteen  elements.  Of  course,  if 
no  precipitates  or  signs  appear  at  any  one  stage  of 
the  analysis,  proceed  immediately  to  the  next,  for  it 
is  not  probable  that  any  mineral  will  ever  contain 
even  one-half  the  elements  mentioned  in  the  assay, 
but  the  full  number  is  given  so  as  to  reach  any 
possible  case. 

II.      DRY    ASSAY    OF    ORES. 

We  have  given  the  wet  assay  method,  and  we 
now  give  as  much  of  the  dry  assay  as  may  generally 
be  called  for.  v 

What  will  be  first  needed  in  the  dry  assay  are 
crucibles,  scorifiers  and  cupels.  Crucibles  for 
general  purposes  are  made  of  coarse  material,  and 
are  called  Hessian.  They  are  sold  in  nests  of  five 
or  more.  The  only  sizes  of  much  value  are  those 
holding  about  6  to  8  ounces.  Scorifiers  are  flat, 
but  thick,  clay  saucers  intended  to  prepare  the 
rough  ore  for  the  finer  treatment  by  use  of  the 
cupel  and  in  the  assay  furnace.  The  cupel  is  a 
little  saucer  of  bone-ash,  intended  to  be  used  on  the 
floor  or  bottom  of  a  heated  muffle  in  the  assay 
furnace.  The  muffle  is  a  clay  oven  of  small 
dimensions,  intended  to  protect  the  scorifier  and 
cupel  from  the  coals  of  the  furnace.  They  can  be 
obtained  at  any  chemical  warehouse. 

An  assay  furnace  may  be  made  of  sheet-iron;  it 


ANALYSES    OF    ORES. 


95 


Fig.  35. 


should  be  some  15  inches  in  diameter,  with  a  grate 
near  the  bottom,  and  lined  with  either  ordinary  or 
fire  brick. 

In  the  accompanying  figure  35  is  given  the  gen- 
eral form  of  one  which  has  been  used  for  years  with 
perfect  success. 

A  plain  sheet-iron  cylinder  (Fig.  35)  18  inches 
high  and  15  inches  in  diameter,  with  draft  hole  at 
A,  muffle  hole  at  B,  and  pipe- 
hole  at  C,  and  lined,  as  has  been 
said,  with  brick,  will  answer  all 
purposes  of  the  best  assays.  The 
hole  at  C  must  have  a  collar 
and  pipe  either  for  a  chimney 
or  it  must  enter  a  chimney.  B 
must  be  provided  with  a  flanged 
door,  as  also  the  draft  hole  A. 
The  top  may  have,  loosely  laid 
on,  only  a  square  sheet  of  heavy 
sheet-iron,  and  the  whole  placed 
upon  a  flat  stone  or  few  bricks.  Several  heavy 
bars  of  iron  nicked  into  the  bricks  will  answer 
where  there  is  no  iron  foundry  at  hand  to  cast  a 
grating  D.  Charcoal  or  coke  may  be  used,  or, 
where  the  draft  is  strong,  a  hard  coal. 

The  crucible  should  be  lined  with  charcoal  finely 
pulverized  and  made  pasty  with  molasses  or  any 
syrup.  This  process  is  called  "brasquing."  Heat 
the  crucible  before  using,  to  dry  out  the  syrup. 

For  field  testing  a  small  portable  assay  furnace, 
using  preferably  some  form  of  gaseous  fuel,  is  of 


-  ©   - 

""            B 
D 

cs 

96        prospector's  field-rook  and  guide. 

great  advantage.  Such  a  furnace  is  made  by  E. 
H.  Sargent  &  Son,  of  Chicago,  Illinois.  It  has  the 
advantages  of  only  weighing  7  lbs.,  being  about  5 
by  8  inches,  when  set  up  is  about  20  inches  in 
height,  and  it  packs  in  a  space  of  1  cubic  foot  with 
all  the  necessary  material — the  box  then  weighs 
ready  packed,  some  25  lbs.  (without  mortar  and 
pestle);  and  lastly,  one  of  the  greatest  recommenda- 
tions is  that  refined  petroleum  is  used  as  the  fuel. 
This  form  of  fuel  is  much  more  easily  obtained,  and 
is  less  dangerous  than  gasolene,  which  is  the  liquid 
fuel  most  commonly  used  for  assaying. 

If  the  object  is  to  obtain  the  amount  of  iron  in 
an  ore,  pulverize  the  ore  to  about  forty  to  the  inch, 
weigh  it,  mix  it  with  charcoal  and  cast  the  mixture, 
from  a  piece  of  paper,  on  the  bottom  of  the  crucible, 
cover  it  with  charcoal  an  inch  or  two  deep,  drop  in 
two  or  three  pieces  of  brick,  and  place  the  crucible 
in  the  hottest  part  of  the  fire,  cover  all  with  coal 
and  gradually  increase  the  heat  and  keep  it  nearly 
at  white  heat  for  half  an  hour,  draw  it  out,  jar  the 
crucible  down  on  a  stone  to  settle  the  melted 
button.  When  cool  take  out  the  contents,  and  the 
metallic  iron  will  be  found  with  its  slag  attached. 
Clean  the  button,  weigh  it,  and  the  weight  of  the 
ore  used  is  to  the  weight  of  the  button  as  100  is  to 
the  per  cent,  of  iron  in  that  ore ;  that  is,  multiply 
the  weight  of  the  button  by  100  and  divide  by  the 
weight  of  the  ore  used. 

Scales,  Weighing,  etc.  Any  scales  that  weigh 
from  J  oz.  to  \  lb.  or  a  greater  amount  will  serve 


ANALYSES    OF    ORES.  97 

for  the  rough  work  in  the  field.  The  cheapest  and 
lightest  scale  is  one  used  for  weighing  letters,  which 
weighs  from  J  oz.  to  12  ozs.;  but  a  better  scale  is 
a  light  spring  balance,  weighing  up  to  2  lbs.,  and 
divided  into  J  and  J  ozs. 

The  sample  can  best  be  weighed  by  laying  it  on 
a  sheet  of  paper,  turning  up  the  edges,  and  tying 
them  with  a  piece  of  string  which  can  be  hooked 
on  to  the  scales. 

For  more  delicate  work,  a  small  pair  of  scales 
weighing  to  -rio^n  of  a  grain  is  quite  sufficient. 
Such  scales  may  be  bought  at  any  chemical  ware- 
house, made  to  pack  and  carry  with  ease  and  secur- 
ity. When  in  a  fixed  laboratory  at  home,  the 
scales  weighing  to  0.0077  grain  or  half  a  milligram 
will  save  chemicals,  time  and  work  ;  but  unless  the 
analyst  has  an  absolutely  true  average  of  the  ton  of 
ore  most  carefully  chosen,  the  smaller  the  amount 
of  ore  used  the  more  likely  is  the  assay  to  prove 
deceptive  when  proportioned  to  the  ton. 

Pulverization  for  the  dry  method  should  never 
be  more  than  50  or  60  to  the  inch.  Smaller  par- 
ticles are  apt  to  be  lost  or  separated  in  the  crucible. 
Obtain  a  piece  of  silk  bolting  cloth  from  a  flour 
miller  or  from  the  source  from  which  he  gets  his 
cloth,  and  select  two  or  three  grades,  one  for  "  wet 
analysis,"  which  may  be  as  fine  as  80  to  the  inch. 
Have  a  rim  made  by  the  tinner  to  tie  on  the  siev- 
ing cloth,  or  use  a  cracked  beaker  glass,  cutting  it 
off  by  the  method  we  have  already  given.  (See 
previous  note,  page  85.) 
7 


98 

Gold  and  Silver  Ores.  These  ores  require  pre- 
paration in  the  scorifier.  Powder  the  ore.  Take 
about  50  grains  of  the  powdered  ore,  500  to  1000 
grains  of  lead  shavings,  according  to  the  probable 
amount  of  silver,  and  about  50  grains  of  borax. 
Mix  the  ore  with  half  the  lead  and  place  the  mix- 
ture in  the  scorifier,  spread  the  other  half  of  lead 
over  the  contents,  and  finally  spread  the  borax  over 
all.  Put  the  scorifier  in  the  muffle,  close  the  door, 
and  heat  up  to  fusion — then  the  door  should  be 
partly  opened,  the  heat  increased,  until  the  oxidized 
lead  (litharge)  covers  the  scorifier.  Take  the  latter 
from  the  muffle  and  pour  the  contents  into  an  iron 
cavity  or  mould,  separate  the  button  and  hammer 
it  into  the  shape  of  a  cube.  It  is  now  ready  for 
cupellation  as  it  contains  all  the  gold  and  silver. 

Cupellation.  By  this  process  the  lead  is  simply 
separated  from  the  gold  and  silver,  the  separation 
being  effected  both  by  absorbing  and  oxidizing. 
Cupels  may  be  made  by  operator,  but  they  can  be 
bought  so  cheaply  that  it  is  seldom  worth  the 
trouble  to  make  them. 

Push  a  cupel  into  the  heated  muffle,  place  the 
cube  of  lead  in  the  cupel  with  little  tongs,  and  heat 
up  till  the  lead  melts,  watch  the  lead  gradually 
wasting  away  until  reduced  to  the  size  of  the  silver 
it  contains,  when  the  surface  will  become  instan- 
taneously bright  and  nothing  remains  but  the  silver 
containing  the  gold.  Withdraw  the  cupel  and  cool 
and  weigh  the  ball.  The  gold  and  silver  must  be 
separated  by  the  wet  process,  thus  :  Dissolve  the  ball 


ANALYSES    OF    ORES.  99 

in  strong  nitric  acid  with  heat  till  the  acid  boils ;  a 
dark  powder  precipitates  ;  filter  off  the  dark  powder, 
it  is  the  gold,  and  precipitate  the  silver  by  solution 
of  common  table  salt  or  by  hydrochloric  acid.  After 
all  is  precipitated  drop  into  the  white  precipitate 
some  pieces  of  zinc,  add  more  hydrochloric  acid — 
hydrogen  gas  is  generated,  which  reduces  the  white 
silver  chloride  to  powdered  metallic  silver.  The 
gold  and  the  silver  may  now  be  melted  in  separate 
crucibles,  weighed  and  compared  with  the  amount 
of  ore  used. 

In  these  trials  the  lead  should  first  be  cupelled 
for  its  silver,  and  that  substracted  from  the  silver 
found,  as  almost  all  leads  contain  some  silver. 

If  it  should  be  more  convenient  to  melt  the  ore 
in  a  crucible  rather  than  a  scorifier,  use  the  follow- 
ing flux  :  If  the  ore  is  composed  chiefly  of  rock,  pul- 
verize, take  100  to  500  grains  of  ore,  red  lead  500 
grains,  charcoal  powder  20  to  25  grains,  carbonate 
of  soda  and  borax  together  500  grains — the  more 
rock  the  more  carbonate  of  soda,  the  more  metallic 
bases  the  more  borax.  Place  a  little  borax  over  all 
and  melt  till  all  is  liquid,  requiring  about  20  min- 
utes ;  withdraw,  extract  the  button  when  cool,  ham- 
mer up  to  a  cube  and  cupel.  Separate  the  gold  and 
silver  as  before,  but  remember  that  the  amount  of 
silver  must  be  three  times  that  of  the  gold,  and  if 
there  is  reason  to  believe  that  there  is  not  this 
amount,  some  silver  must  be  melted  with  the 
button,  since  the  separation  will  not  otherwise  be 
complete. 


T.  S.  G.  Kirkpatick  recommends  the  following 
process  of  assaying  gold  quartz  :  Take  200  grains  of 
ore,  500  of  litharge,  6  of  lamp-black  and  500  of  car- 
bonate of  soda;  or,  200  grains  of  ore,  200  of  red 
lead,  150  of  carbonate  of  soda,  8  of  charcoal  and  6 
of  borax.  Mix  and  put  into  a  warmed  crucible, 
and  cover  with  half  an  inch  of  common  salt.  Fuse 
in  a  hot  fire  30  minutes  ;  cool  and  break  the  pot ; 
clean  the  button  with  a  small  hammer. 

If  the  quartz  is  very  pyritous,  take  100  grains 
and  calcine  "  dead  "  without  clotting,  add  500  grains 
of  red  lead,  35  of  charcoal,  400  of  borax,  and  400  of 
carbonate  of  soda,  cover  with  salt  and  proceed  as 
above.     In  each  case  cupel  the  button. 

As  the  bone  ash  of  which  the  cupel  is  made  can 
absorb  its  own  weight  of  metallic  oxides,  the  cupel 
chosen  should  always  exceed  the  weight  of  the 
button  to  be  operated  on,  so  as  to  have  a  margin. 
Boil  the  gold  prill  obtained  from  cupelling  in  nitric 
acid,  which  dissolves  the  silver  and  leaves  the  gold 
pure. 

The  above  formula  are  open  to  modifications  by 
the  operator  according  to  the  apparent  richness  or 
poverty  of  the  ore  to  be  treated,  and  the  presence 
and  character  of  the  basic  impurities.  In  case  there 
are  oxides,  a  reducing  agent  is  required ;  and  if 
sulphides,  an  oxidizing  agent.  As  a  rule,  employ  a 
weight  of  litharge  twice  that  of  the  ore,  and  of  car- 
bonate of  soda  the  same  as  the  ore.  These  reagents 
are  added  to  control  the  size  of  the  lead  button,  and 
to  obtain  one  of  suitable  size  for  cupelling. 


ANALYSES   OF    ORES.  101 

Lead  Ore,  Galena.  The  charge  for  the  cru- 
cible is  carbonate  of  soda,  two  or  three  times  the 
weight  of  the  ore,  three  or  four  tenpenny  nails  on 
top  to  absorb  the  sulphur,  and  a  covering  of  salt  or 
borax ;  heat  to  redness  about  20  minutes.  Pour 
the  contents  into  a  crucible  and  separate  the  button. 

Copper  Ore.  The  wet  assay  is  better  than  the 
dry,  especially  that  by  the  burette,  which  we  shall 
give  later  on  under  "  Copper." 

Tin  Ore.  If  it  is  mixed  with  iron  or  copper 
pyrites  it  should  be  powdered  and  roasted,  and  then 
mixed  with  one-quarter  of  its  weight  of  charcoal 
and  subjected  to  great  heat  in  a  crucible  for  about 
20  minutes.  Jar  it  as  in  an  iron  assay,  let  it  cool, 
and  pick  out  the  button  or  buttons,  or  pour  it  out 
while  melted. 

It  may  be  reduced  otherwise  by  melting  the  pow- 
dered ore  with  cyanide  of  potassium,  100  grains  of 
ore  to  600  grains  of  cyanide.     Cool,  extract  button. 

This  ore  is  very  hard  and  may  be  powdered  to 
60  to  the  inch. 

Mercury.  These  ores  are  easily  reduced  by 
simply  heating  and  condensing  the  vapors  in  a  cold 
bath  as  in  using  a  retort  and  cool  receiver. 

Antimony.  Place  about  2000  grains  of  ore  pow- 
dered in  a  crucible  having  a  hole  chipped  out  in 
the  bottom,  and  the  hole  stopped  loosely  with  a 
piece  of  charcoal.  Put  this  crucible  into  another 
half-way  down.  Then  lute  on  the  lid  and  put  clay 
around  the  juncture  of  the  two  and  put  live  coals 
around  the  upper  crucible  by  placing  some  broken 


102      prospector's  field-book  and  guide. 

bricks  around  the  lower  one  on  the  grate,  to  keep 
the  coals  away  from  it.  The  antimony  will  melt 
and  leave  its  gangue  rock  in  the  upper  crucible 
while  the  lower  one  will  receive  the  melted  metal. 

Bismuth,  zinc,  manganese,  nickel,  cobalt,  and 
other  metals  should  be  reduced  or  analyzed  by  the 
"  wet  process  "  which  we  have  already  given.  (In 
this  chapter,  V.) 

An  excellent  fire  lute  is  made  of  8  parts  of  sharp 
sand,  2  parts  of  good  clay,  1  part  horse-dung ;  mix 
and  temper  like  mortar. 


CHAPTER  VI. 


SPECIAL    MINERALOGY. 


GOLD. 


We  shall  now  proceed  to  a  more  definite  and 
practical  treatment  of  these  two  subjects,  technical 
mineralogy  and  economic  geology,  so  far,  only,  as 
they  may  be  of  service  in  the  work  before  us. 

The  first  suggestion  which  may  be  made  is  that 
the  best  preparation  for  the  general  study  of  miner- 
alogy is  to  gather  a  collection  of  the  chief  mineral 
substances  with  which  the  student  is  to  come  in 
contact.  In  many  cases  very  small  specimens  are 
sufficient.  As  we  proceed  in  our  treatment  of  each 
substance  it  will  occur  to  the  reader  what  and  how 
much  he  needs  to  obtain.  But  it  should  be  empha- 
sized that  no  amount  of  study  on  the  part  of  the 
student,  nor  of  description  on  the  part  of  the  in- 
structor, can  ever  take  the  place  of  the  actual  spe- 
cimen.* 

Gold. — Gold  is  one  of  the  most  widely  distributed 
metals,  but  generally  speaking,  accumulations  of 
larger  quantities  of  it  are  found  only  in  a  few  local- 
ities. Traces  of  it  pass  from  various  ores  into  arti- 
ficial products,  for  instance,  into  litharge,  minium, 

*  For  list  of  specimens,  see  end  of  book. 

(103) 


104 

white  lead,  silver  and  copper  and  coins  made  there- 
from, etc.  Minute  quantities  of  gold  (about  13 
grains  in  1  ton)  have  been  found  even  in  sea  water 
as  well  as  in  clay  deposits. 

The  chief  supplies  of  gold  are  at  the  present  time 
obtained  from  the  United  States  (California,  Nevada, 
Arizona,  Montana,  Utah,  Alaska,  Colorado)  from 
British  Columbia,  Nova  Scotia,  Mexico,  Peru  and 
Brazil,  from  Australia  (especially  Victoria,  New 
South  Wales,  and  Queensland),  Tasmania,  New 
Zealand,  and  in  Africa  (Natal,  the  Transvaal,  etc.). 
The  Ural  Mountains  and  Siberia  also  yield  consid- 
erable gold.  In  Europe  only  Transylvania  and 
Hungary  are  of  any  importance. 

Gold  occurs  almost  exclusively  in  the  metallic 
state,  either  in  situ,  in  quartz  rock,  especially  along 
with  quartz,  pyrites  and  hydroferrite  ;  also  as  gold 
sand,  in  dust  or  grains,  leaflets  and  rounded  pieces 
(nuggets),  in  the  sands  of  rivers  or  in  alluvial  soils, 
consisting  chiefly  of  clay  and  quartz  sand  along 
with  mica,  water-worn  fragments  of  syenite,  chlorite 
slate,  grains  of  chrome  iron  and  magnetic  iron, 
spinel,  garnet,  etc.  In  the  metallic  state  it  contains 
always  more  or  less  silver  as  electrum.  According 
to  recent  analyses  native  gold  contains : 


Transyl-  South 

vania.  America.  Siberia.  California.  Australia. 

Gold 64.77  38.14  86.50           90.00  99.2  and  95.7 

Silver •    .    35.23  11.96  13.20           10.06  0.43  "     3.8 

Iron  and  other  metals.    —  —  0.30            0.34  0.28"     0.2 

Siberian,  Californian  and  Australian  gold  con- 


GOLD.  105 

tain  not  unfrequently  osmiridium,  palladium  and 
platinum.  Mexican  rhodium-gold  contains  34  to 
43  per  cent,  rhodium.  Gold  amalgam  is  found  in 
California  and  Columbia.  The  so-called  black  gold 
which  occurs  in  nuggets  in  Arizona  and  at  Maldon, 
Victoria,  in  granite  and  quartz  lodes,  is  crystalline 
and  silver-like  when  freshly  fractured,  but  soon 
turns  black  in  the  air.  It  is  bismuth-gold,  with 
64.211  gold,  34.398  bismuth  and  1.591  gangue. 
Gold  is  also  often  met  with  in  native  tellurium  and 
silver  telluride,  sometimes  in  iron  pyrites,  copper 
pyrites,  in  blende,  in  arsenical  pyrites,  and  galena. 
To  detect  a  content  of  native  gold  in  pyrites  bring 
a  few  drops  of  mercury  into  a  porcelain  crucible, 
put  a  perforated  piece  of  cardboard  in  the  crucible 
so  that  it  rests  a  short  distance  above  the  mercury, 
place  a  small  package  of  pyrites  over  the  hole  in 
the  cardboard,  heat  the  crucible  for  some  time  and 
watch  with  the  pocket  lens  for  the  appearance  of 
white  stains  of  gold  amalgam,  which  on  rubbing 
with  a  brush  or  feather  becomes  lustrous. 

Gold  crystallizes  in  the  isomeric  system,  but 
crystals  are  seldom  found.  Figs.  36  and  37  repre- 
sent gold  crystals.  Twin  crystals  are  also  occasion- 
ally found.  In  Sonora,  California,  Blake  found 
gold  in  hexagonal  prisms.  Fig.  38  shows  the 
finest  gold  dust  700  times  magnified,  and  Fig.  39  a 
reduced  illustration  of  a  lump  of  gold  which  was 
found  at  Forest  Creek,  Victoria,  Australia.  It 
weighed  more  than  30  pounds,  and  was  11.33 
inches  long  and   5.15    inches  wide.     The   largest 


106 


PROSPECTOR  S   FIELD-BOOK   AND   GUIDE. 


nugget  of  gold  ever  found  was  at  Ballarat,  Australia. 
It  weighed  over  191  pounds,  and  was  20  inches  long 
and  9  inches  wide. 

The  specific  gravity  of  gold  is  16  to  19.5,  accord- 


Fig.  36. 


Fig.  37. 


Fig.  38. 


ing  to  the  amount  of  alloy  ;  hardness  2.5  to  3.0.  It 
is  the  only  yellow,  malleable  mineral  found  in  the 
natural  state.  Its  color  varies  from  pale  to  deep 
yellow.     In  some  localities,  such  as  in  New  South 


Fig.  39. 


Wales,  Australia,  and  Costa  Eica,  it  is  often  found 
of  a  very  light  color,  but  it  presents  the  same  color 
from  whatever  direction  it  is  looked  at,  and  to  the 
prospector  this  is  a  guiding  test.     Indeed  one  of  the 


GOLD.  107 

most  important  and  useful  accomplishments  for 
gold  exploitation  is  "  an  eye  for  color."  Native 
gold  possesses  a  peculiar  color  which  is  readily  re- 
cognized, although  the  gold  may  be  alloyed  with 
silver  or  copper,  and  its  color  will  in  an  instant  dis- 
tinguish it  in  the  eye  of  the  expert  from  any  condi- 
tion of  pyrites,  whether  iron  or  copper  pyrites. 

Gold  grains  will  always  flatten  when  struck  with 
a  hammer  or  between  two  stones,  whereas  other 
minerals  similar  in  color  will  break  into  fragments. 
Or  if  the  doubtful  particle  is  coarse  enough,  take  a 
needle  and  stick  the  point  into  the  questionable 
specimen.  If  gold,  the  steel  point  will  readily  prick 
it ;  if  pyrites  or  yellow  mica,  the  point  will  glance 
off  or  only  scratch  it. 

Under  the  blow-pipe,  on  a  piece  of  charcoal,  gold 
may  melt,  but  on  cooling  it  always  retains  its  color ; 
any  other  mineral  will  lose  color,  become  black- 
ened, or  will  be  attracted  to  the  end  of  your  pen- 
knife blade,  if  that  blade  has  been  previously 
magnetized,  and  the  unknown  substance  contains 
iron. 

Gold  imparts  no  color  to  boiling  nitric  acid.  It 
will  not  dissolve  in  nitric  or  hydrochloric  acid 
separately,  but  it  does  dissolve  in  the  two  when 
combined,  and  then  the  acid  is  known  as  nitro- 
muriatic  acid  or  aqua  regia.  Proportions :  one 
nitric  to  four  muriatic. 

But  it  is  not  always  a  trustworthy  sign  that  par- 
ticles are  gold  because  they  will  not  dissolve  in 
nitric  acid.     Some  seemingly  gold-colored  particles 


will  not  dissolve  in  nitric  acid,  and  yet  contain  not 
a  trace  of  gold. 

The  simplest  instrument  for  the  discovery  of  gold 
and  the  estimation  of  the  value  of  an  auriferous 
material  in  which  the  gold  is  contained  in  a  free 
state,  is  the  ordinary  miner's  pan,  a  circular  dish  of 
Russian  sheet-iron,  about  12  inches  wide  and  3 
inches  deep,  with  sloping  sides.  There  should  be  a 
slight  indentation  all  round  where  the  sides  join 
the  bottom,  so  as  to  afford  lodging  for  the  gold 
grains,  and  the  more  rusty  it  is  the  better.  A  fry- 
ing pan  free  from  grease  will  answer  very  well  on  a 
pinch.     The  South  American  batea,  Fig.  40,  made 

Fig.  40. 


of  hard  wood  in  a  solid  piece,  and  hollowed  out  like 
a  shallow  funnel,  is  a  superior  implement  when  in 
capable  hands.  Another  good  substitute  for  this 
pan  is  a  kind  of  magnified  shovel  without  handle 
made  of  linden  wood  and  provided  with  a  vertical 
wall  on  three  sides.  The  wooden  implements 
should  be  slightly  charred  on  the  surface  to  show 
up  the  gold  grains,  and  should  not  have  been  used 
to  hold  mercury  or  amalgam. 

The  object  of  panning  out,  as  the  operation  with 
the  pan  or  batea  is  called,  is  to  settle  and  collect  at 
the  bottom  of  the  pan  the  heaviest  portions  of  the 


GOLD.  109 

material  subjected  to  the  test.  Simple  as  the  pro- 
cess of  panning  appears  to  be,  dexterity  is  only  ac- 
quired by  considerable  practice.  In  outline  the 
operation  is  as  follows  : 

A  quantity  of  the  dirt  to  be  washed  is  placed  in 
the  pan,  sufficient  to  occupy  about  two-thirds  of  its 
capacity.  The  pan  with  its  contents  is  then  im- 
mersed in  water,  either  in  a  hole  or  in  a  rivulet,  of 
such  a  depth  that  the  operator  can  conveniently 
reach  the  pan  with  his  hands  while  it  rests  on  the 
bottom.  The  object  of  this  is  to  give  him  free  use 
of  both  his  hands  for  stirring  up  the  mass,  so  that 
every  particle  may  become  thoroughly  sodden  and 
disintegrated.  Of  course  the  pan  may  be  held  in 
one  hand,  and  its  contents  stirred  with  the  other, 
but  the  disadvantages  of  such  a  method  are  obvious. 

When  the  dirt  has  become  thoroughly  soaked  and 
permeated  by  the  water,  the  pan  is  taken  in  both 
hands,  one  on  either  side,  and  a  little  inside  of  its 
greatest  diameter,  and  without  allowing  it  to  emerge 
from  the  water,  it  is  suspended  in  the  hands,  not 
quite  level,  but  tipping  somewhat  away  from  the 
person.  In  this  position  it  is  shaken  so  as  to  allow 
the  water  to  disengage  all  the  light  earthy  particles 
and  carry  them  away.  When  this  has  been  con- 
cluded there  will  remain  in  the  pan  varying  pro- 
portions of  gold  dust,  heavy  sand,  lumps  of  clay, 
and  gravel  stones.  These  last  accumulate  on  the 
surface,  and  are  picked  off  by  hand  and  thrown 
aside.  The  lumps  of  clay  must  be  crumbled  and 
reduced  by  rubbing,  so  as  to  be  carried  off  by  the 


110 

water  during  the  next  immersion  of  the  pan.  A 
neat  turn  of  the  wrist  is  required  to  allow  the 
muddy  waters  to  escape  in  driblets  over  the  de- 
pressed edge  of  the  pan,  without  exercising  so  much 
force  as  to  send  the  lighter  portion  of  the  gold  after 
them.  At  last  nothing  remains  in  the  pan  but  the 
gold  dust,  with  usually  some  heavy  black  sand  and 
a  little  earthy  matter.  By  the  final  careful  wash- 
ing with  plenty  of  clean  water,  the  earthy  matters 
can  be  completely  removed,  but  the  heavy  iron  sand 
cannot  be  got  rid  of  by  any  method  based  upon  its 
specific  gravity  relatively  to  that  of  gold. 

To  remove  the  iron  sand,  one  of  two  simple  plans 
has  to  be  adopted.  If  the  sand  be  magnetic,  as  is 
usually  the  case,  it  may  be  eliminated  to  the  last 
grain  by  stirring  the  mass  carefully  with  a  powerful 
magnet,  care  being  taken  that  no  particles  of  gold 
become  mechanically  suspended  among  the  black 
sand. 

Where  this  is  ineffectual,  recourse  must  be  had  to 
blowing.  For  this  purpose  the  mass  of  gold  dust 
and  iron  sand  is  allowed  to  become  perfectly  dry, 
and  small  quantities  of  it  at  a  time  are  placed  in  an 
instrument  called  a  blower — a  sort  of  a  shallow 
scoop,  made  of  tin  and  open  at  one  end.  Holding 
the  blower  with  its  mouth  pointed  away  from  him, 
and  gently  shaking  it  so  as  constantly  to  change  the 
position  of  the  particles,  the  operator  blows  gently 
along  the  surface  of  the  contents,  regulating  the 
force  and  direction  of  his  breath  so  as  to  remove  the 
sand  without  disturbing  the  gold.     Where  water 


GOLD. 


Ill 


can  be  had,  a  pan  is  the  most  efficient  instrument  a 
man  can  travel  with  in  his  gold-seeking  journeys. 

A  crude  apparatus  formerly  much  used  in  Cali- 
fornia and  Australia  is  called  the  cradle  or  rocker. 
This,  as  shown  on  Fig.  41,  is  a  trough  of  some  7 
feet  in  length  and  2  broad.  Across  the  bottom 
of  this  several  bars  are  nailed  at  equal  distances, 
and  at  the  upper  end  a  kind  of  sieve  is  fixed  at  about 
a  foot  above  the  bottom.     This  whole  arrangement 

Fig.  41. 


is  mounted  upon  rollers.  To  operate  the  apparatus 
four  men  are  required.  One  man  digs  out  the 
earth  from  the  hole,  a  second  supplies  the  cradle 
sieve  with  this  auriferous  earth,  a  third  keeps  up  a 
supply  of  water  which  he  pours  upon  the  earth  in 
the  sieve,  while  a  fourth  keeps  the  machine  contin- 
ually moving  upon  the  rollers.  The  large  stones 
washed  out  are  removed  by  hand  from  the  sieve, 


112 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


and  the  water  at  the  same  time  washes  the  smaller 
substance  through,  which  is  slowly  carried  towards 
the  lower  end  of  the  trough  by  a  slight  inclination 
given  to  the  whole.  Thus  the  flow  of  water  tends 
to  keep  the  earthy  particles  in  suspension  so  as  to 
allow  of  their  washing  off,  while  the  heavier  por- 
tions of  gold  are  obstructed  in  their  flow,  and  re- 
tained against  the  cross  bars  fixed  to  the  cradle 
bottom.  These  are  removed  from  time  to  time  and 
dried  in  the  sun,  when,  after  blowing  away  lighter 
particles,  the  metal  only  further  requires  to  be 
melted. 

A  more  efficient  apparatus  is  the  long  torn,  Fig. 

Fig.  42. 


£5 


42.  A  torn  that  will  serve  the  purpose  of  the  pros- 
pector can  be  easily  manufactured  on  the  spot  where 
it  is  decided  to  test  the  ore  of  a  newly  discovered 
reef.  A  serviceable  supply  of  tools  must  of  course 
be  comprised  in  his  outfit,  including  one  or  two 
good  adzes  for  giving  a  smooth  plank  surface  to  the 
side  of  the  timber  which  forms  the  floor  or  sides  of 
the  torn.  A  rough  but  quite  efficient  apparatus  can 
by  this  method  be  constructed  in  a  short  time, 


GOLD.  113 

The  torn  consists  essentially  of  two  separate 
troughs  as  shown  in  the  figure.  These  are  placed 
on  an  incline,  or  given  an  inclination  by  log  or 
rock  supports.  The  California  torn  is  about  12  feet 
long,  20  inches  wide  at  the  upper  end,  and  widen- 
ing gradually  to  30  inches  at  the  mouth.  A  stream 
of  water  flows  in  by  the  spout  just  over  the  place 
where  the  dirt  is  introduced  into  the  upper  box  or 
torn  proper.  The  dirt  is  constantly  thrown  in  by 
one  man,  while  a  second  is  occupied  in  stirring  it 
about  with  a  square-mouthed  shovel,  or  a  fork  with 
several  blunt  prongs,  which  is  useful  for  pitching 
out  the  heavy  boulders  that  sometimes  occur,  and 
for  tossing  back  undissolved  lumps  of  clay  against 
the  current.  The  lower  end  of  the  torn  is  cut  off 
obliquely,  so  that  the  mouth  may  be  stopped  by  a 
sheet  of  perforated  iron.  The  sheet  of  iron  should 
be  closely  perforated  with  one-half  inch  holes — or 
smaller  if  the  pay  dirt  is  very  fine — about  20  inches 
square. 

The  apparatus  being  placed  on  an  incline  amount- 
ing generally  to  12  inches,  the  materials  all  gravi- 
tate with  the  water  towards  this  sloping  grating  at 
the  mouth,  everything  passing  through  it  except 
the  large  stones  which  gather  on  the  grating,  and 
are  removed  as  often  as  necessary.  Beneath  this 
grating  stands  what  is  called  -the  riffle  box  into 
which  all  the  fine  matters,  including  the  gold  de- 
scend. The  riffle  box,  like  the  torn  proper  is  made 
of  rough  plank,  and  is  also  placed  on  an  incline, 
but  only  just  so  that  tb§  wa.ter  passing  oyer  it  will 
8 


114 

allow  of  the  bottom  becoming  and  remaining  cov- 
ered with  a  thin  coating  of  fine  mud.  In  this  way 
the  gold  and  a  few  of  the  heaviest  minerals  will  find 
their  way  to  the  bottom  and  rest  there,  especially 
by  the  help  of  the  riffle  bars,  which  give  their  name 
to  the  apparatus.  Sometimes  a  little  mercury  is 
put  behind  the  riffles,  so  as  to  assist  in  retaining 
the  gold,  and  occasionally  the  riffle  box  is  supple- 
mented by  a  series  of  blankets,  which  are  useful  for 
catching  the  very  fine  gold. 

The  torn  is  cleaned  out  periodically,  and  the  gold 
and  amalgam  are  panned  out.  The  torn  employs 
two  to  four  men  according  to  the  character  of  the 
dirt  and  the  supply  of  water.  It  is  applicable  to 
diggings  where  the  gold  is  coarse,  it  being  quite  in- 
capable of  saving  all  fine  gold,  of  which  at  least  10 
per  cent,  may  be  estimated  as  lost. 

The  amalgam  and  mercury  taken  out  must  be 
pressed  through  buckskin  or  canvas  to  remove  the 
excess  of  mercury,  which  will  run  into  a  vessel 
placed  to  catch  it.  The  remaining  sponge-like  mass 
of  amalgam  must  be  retorted  to  extract  the  gold. 

Washing  the  dirt  is  also  affected  by  sluices  having 
an  inclination  of  about  8  feet  in  12  feet.  These 
sluices  consist  of  a  series  of  troughs  formed  by 
planks  nailed  together,  the  length  of  each  being 
about  10  or  12  feet,  the  height  8  inches  to  2  feet, 
the  width  1  to  4  feet.  By  making  one  end.  of  the 
bottom  plank  of  each  trough  4  inches  narrower 
than  at  the  other,  the  troughs  can  be  telescoped  into 
one  another  and  so  a  sluice  of  very  great  length  can 


GOLD. 


115 


be  formed.  Across  the  inside  of  the  bottom-planks, 
small,  narrow  strips  of  wood  2  inches  or  so  thick, 
and  3  or  more  inches  wide,  are  fixed  across,  or  some- 
times at  angles  of  45°  to  the  side  of  the  trough, 
at  short  intervals  apart.  Running  water  washes 
downward  the  earth  thrown  into  the  sluice,  which 
is  open  on  the  top  side,  and  the  gold  dust  accumu- 
lates, sometimes  assisted  by  the  aid  of  mercury 
allowed  to  trickle  out  of  a  vessel  from  riffle  to  riffle, 


Fig.  43. 


in  front  of  the  bars,  while  the  lighter  matter  is 
washed  downwards. 

A  still  more  effective  method  is  what  is  called 
hydraulic  mining,  and  under  favorable  circum- 
stances, such  as  a  plentiful  supply  of  water  with 
good  fall  and  extensive  loose  auriferous  deposits,  a 
very  small  amount  of  gold  to  the  ton  can  be  made 
to  give  paying  returns.  The  water  is  conducted  in 
flumes  or  pipes  to  a  point  near  where  it  is  required, 
thence  in  wrought-iron  pipes  gradually  reduced  in 


116      prospector's  field-book  and  guide. 

size  and  ending  in  a  great  nozzle  somewhat  like 
that  of  a  fireman's  hose.  Figs.  43  and  44  show  the 
arrangement.  Fig.  43  exhibits  the  mouth-piece 
movable  at  A  B  in  an  ascending,  and  at  C  D  in  an 
inclined,    direction.     E    is    a    lever    loaded    with 


■ScO/fa*^  ,.-. 


weights,  which  facilitates  the  adjustment  of  the 
mouth-piece  by  the  operator  in  any  direction.  The 
method  of  operating  the  arrangement  will  be  seen 
from  Fig.  44.  A  is  the  water-distributor,  B  the 
nozzle,  C  channels  for  carrying  off  the  debris  de- 
tached from  the  ledge ;  D,  piles  of  larger  pieces  of 


GOLD.  117 

rock  which  are  finally  comminuted.  Tis  a  tunnel 
through  which  the  water  reaches  the  gutter,  pro- 
vided with  the  grating  F  through  which  the  finer 
stuff  falls  into  the  shallow  settling  basin  E,  and  is 
distributed  by  blocks  G,  while  the  principal  mass  of 
water  with  the  coarser  material  passes  over  the 
grating  F  into  the  principal  sluice  in  which  the 
grating  H  retains  the  larger  pieces  which  are  then 
thrown  out  at  /.  The  basins  E  and  the  principal 
sluice  are  paved  with  wooden  blocks  or  stones  be- 
tween which  mercury  is  placed.  The  amalgam 
formed  is  freed  from  admixtures  in  a  mercury  bath, 
pressed  through  sail-cloth,  boiled  in  sulphuric  acid 
and  distilled. 

On  nearly  all  alluvial  gold  fields,  whether  shal- 
low placers  or  deep  leads,  is  found  a  stratum  of 
ferruginous  conglomerate,  composed  principally  of 
rounded  and  angular  fragments  of  quartz  of  all 
sizes,  cemented  together  by  the  oxide  of  iron  with 
which  the  mass  is  impregnated,  and  often  so  hard 
as  to  resist  everything  but  blasting.  This  cement, 
as  it  is  called,  overlies  the  bed-rock,  in  some  places 
resting  on  it,  in  others  several  inches  or  even  feet 
above  it.  In  thickness  it  fluctuates,  from  6  inches 
to  8  feet  or  more.  Its  character  varies  but  little. 
It  is  often  highly  auriferous,  and  is  worthy  of  special 
attention.  It  should  be  pounded  to  a  fine  powder 
and  tested. 

Many  particles  of  fine  gold,  notwithstanding 
their  greater  specific  gravity  exhibit  the  tendency 
to  float  in  water  when  undergoing  a  washing  pro- 


118      prospector's  field-book  and  guide. 

cess.  To  save  this  fine  flour  or  float-gold,  as  it  is 
called,  experiments  have  shown  that  by  heating  the 
water  to  the  boiling-point  or  nearly  so,  these  float- 
ing particles  of  gold  will  subside  to  the  bottom  of 
the  pan  or  vessel. 

Burning  and  Drifting.  The  labor  of  removing  the 
barren  gravel  which  overlies  the  pay  dirt  is  very 
great,  but  ordinarily  this  is  undertaken  when  the 
thickness  is  not  considerable.  With  increasing 
thickness  a  point  is  soon  reached  where  the  task  of 
removing  it  becomes  so  formidable  that  the  miner 
will  not  make  the  attempt  unless  he  believes  that 
there  is  rich  pay  dirt  beneath.  In  this  event  the 
practice  is  adopted  of  sinking  shafts  through  the 
barren  material  to  the  pay  dirt,  and  extracting  the 
pay  dirt  by  means  of  tunnels  or  drifts  along  the  sur- 
face of  the  bed-rock.  This  method  of  working  has 
been  adopted  only  lately,  but  promises  to  be  very 
important.  The  ordinary  methods  of  sinking/drift- 
ing, timbering,  stoping,  etc.,  have  been  peculiarly 
modified  in  the  Forty-mile  District,  Alaska,  on  ac- 
count of  the  exceptional  character  of  the  climate, 
and  these  modifications  have  spread  from  this  dis- 
trict over  the  rest  of  the  gold  diggings.  Owing  to 
the  severity  and  length  of  the  winters  the  gravels 
are  frozen  during  seven  or  eight  months  of  the  year. 
The  miner  who  desires  to  sink  a  shaft  waits  until 
the  cold  season  arrives,  and  then  sinks  through  the 
frozen  ground,  which  is  so  firm  that  the  shafts  or 
drifts  do  not  need  timbering  for  the  sake  of  support. 
In  sinking  or  drifting,  instead  of  employing  powder 


GOLD.  119 

and  pick,  as  elsewhere,  a  small  fire  is  built  at  the 
bottom  of  the  shaft  which  is  being  sunk,  or  at  the 
face  of  the  drift  which  is  being  run,  and  thus  the 
gravels  are  thawed  out  for  some  distance  and  can  be 
easily  taken  up  and  brought  to  the  surface.  It  takes 
a  surprisingly  small  amount  of  wood  to  run  a  drift 
through  the  frozen  gravel  for  a  long  distance.  In 
this  way  the  pay  dirt  is  extracted  and  accumulates 
on  the  surface  until  spring,  when  it  is  shoveled  into 
sluices  and  the  gold  is  separated  by  washing,  pan- 
ning, blowing  and  amalgamation  in  the  manner  pre- 
viously described.  One  large  chamber  or  "stope" 
thus  excavated  in  the  gravels  of  Miller  Creek  in  the 
Forty-mile  District,  is  said  to  have  measured  64  by 
32  feet,  and  19  feet  in  height,  with  only  8  feet  of 
barren  gravel  between  it  and  the  surface ;  and  yet 
this  stood  firmly  until  spring,  when  the  gravels 
thawed  and  the  stope  caved  in. 

For  lode  prospecting  a  pestle  and  mortar  should  be 
carried.  The  handiest  for  traveling  is  a  mortar 
made  from  a  mercury  bottle  cut  in  half,  and  a  not 
too  heavy  wrought-iron  pestle  with  a  hardened  face. 
To  get  the  stuff  to  regulated  fineness  a  fine  screen  is 
required,  and  the  best  for  the  prospector  who  is 
often  on  the  move,  is  made  from  a  piece  of  cheese 
cloth  stretched  over  a  small  hoop.  It  is  often 
desirable  to  heat  the  rock  before  crushing,  as  it  is 
thus  more  easily  triturated  and  will  reveal  all  its 
gold.  Having  crushed  the  gangue  to  a  fine  powder, 
proceed  to  pan  it  off  in  the  same  manner  as  washing- 
out  alluvial  earth,  except  that  in  prospecting  quartz 


one  has  to  be  much  more  particular,  as  the  gold  is 
usually  finer.  Take  the  pan  in  both  hands  and 
admit  enough  water  to  cover  the  pulverized  sub- 
stance by  a  few  inches.  The  whole  is  then  swirled 
around  and  the  dirty  water  poured  off  from  time  to 
time  till  the  residue  is  clean  quartz  sand  and  heavy 
metal.  Then  the  pan  is  gently  tipped  and  a  side  to 
side  motion  given  to  it,  thus  causing  the  heavier 
contents  to  settle  down  in  the  corner.  Next  the 
water  is  carefully  lapped  in  over  the  side,  the  pan 
being  now  tilted  at  a  greater  angle  until  the  lighter 
particles  are  all  washed  away.  The  pan  is  then 
once  more  righted  and  very  little  water  is  a  few 
times  passed  over  the  pinch  of  heavy  mineral,  when 
the  gold  will  be  revealed  in  a  streak  along  the 
bottom.  In  this  operation,  as  in  all  others,  only 
practice  will  make  perfect,  and  a  few  practical  les- 
sons are  worth  whole  pages  of  written  instruction. 

J.  C.  F.  Johnson  *  gives  the  following  directions 
for  making  an  amalgamating  assay  that  will  prove 
the  amount  of  gold  which  can  be  got  from  a  ton  of 
a  lode.  Take  a  number  of  samples  from  different 
parts,  both  length  and  breadth.  The  drillings  from 
the  blasting  bore-holes  collected  make  the  best  test. 
When  finely  triturated  weigh  off  one  or  two  pounds, 
place  in  a  black  iron  pan  (it  must  not  be  tinned) 
with  4  ounces  of  mercury,  4  ounces  common  salt,  4 
ounces  soda,  and  about  half  a  gallon  of  boiling  water. 
Then  with  a  stick,  stir  the  pulp  constantly,  occasion- 

*  "  Getting  Gold."  London,  1897. 


GOLD.  121 

ally  swirling  the  dish  as  in  panning  off,  till  you  feel 
certain  that  every  particle  of  the  gangue  has  come 
in  contact  with  the  mercury.  Then  carefully  pan 
off  into  another  dish  so  as  to  lose  no  mercury. 
Having  got  your  amalgam  clean,  squeeze  it  through 
a  piece  of  chamois  leather,  though  a  good  quality 
of  new  calico  previously  wetted  will  do  as  well. 
The  resulting  pill  of  hard  amalgam  can  then  be 
wrapped  in  a  piece  of  brown  paper,  placed  on  an 
old  shovel,  and  the  mercury  driven  off  over  a  hot 
fire.     Or   a   clay  tobacco   pipe,   the   mouth  being 

Fig.  45. 


stopped  with  clay,  makes  a  good  retort.  To  make 
such  a  retort,  Fig.  45,  take  two  new  tobacco  pipes 
similar  in  shape,  with  the  biggest  bowls  and  longest 
stems  procurable.  Break  off  the  stem  of  one  close 
to  the  bowl  and  fill  the  hole  with  well-worked  clay. 
Set  the  stemless  pipe  on  end  in  a  clay  bed,  and  fill 
with  amalgam,  pass  a  bit  of  thin  iron  or  copper 
wire  beneath  it,  and  bend  the  end  of  the  wire 
upwards.  Now  -fit  the  whole  pipe,  bowl  inverted, 
on  to  the  under  one,  luting  the  edges  well  with  clay. 
Twist  the  wire  over  the  top  with  a  pair  of  nippers 


122 

till  the  two  bowls  are  fitted  closely  together,  and 
you  have  a  retort  that  will  stand  any  heat  neces- 
sary to  thoroughly  distill  mercury.  The  residue, 
after  the  mercury  has  been  driven  off,  will  be  re- 
torted gold,  which,  on  being  weighed  and  the  result 
multiplied  by  2240  for  1  pound  assay,  or  by  1120 
for  two  pounds,  will  give  the  amount  of  gold  per 
ton  which  an  ordinary  battery  might  be  expected 
to  save.  Thus  1  grain  to  the  pound,  2240  pounds 
to  the  ton,  would  show  that  the  stuff  contained  4 
ounces,  13  pennyweights,  8  grains  per  ton. 

Darton's  gold  test.  Darton  remarks  that  a  num- 
ber of  methods  have  been  proposed  to  detect  the 
minute  quantities  of  gold  occurring  in  rocks,  etc., 
and  having  examined  and  tested  every  method,  re- 
commends the  following  as  requiring  but  little  time 
and  being  very  trustworthy. 

Small  parts  are  chipped  from  all  the  sides  of  a 
mass  of  rock  amounting  in  all  to  about  J  oz.  This 
is  finely  powdered  in  a  steel  mortar,  and  well  mixed. 
About  half  of  it  is  placed  in  a  capacious  test  tube, 
and  then  partly  filled  with  a  solution  made  by  dis- 
solving 20  grains  of  iodine  and  30  grains  of  iodide 
of  potassium  in  about  1 J  ozs.  of  water. 

The  mixture  thus  formed  is  thoroughly  agitated 
by  shaking  and  warming.  Then  after  all  particles 
have  subsided,  dip  a  piece  of  pure  white  filter  paper 
in  it,  allow  it  to  remain  for  a  moment,  then  let  it 
drain,  and  dry  it  over  the  spirit  lamp.  It  is  then 
placed  upon  a  piece  of  platinum  foil  held  by  pincers, 
and  heated  to  redness  over  the  flame.     The  paper 


GOLD.  123 

is  speedily  consumed,  and  after  heating  further  to 
burn  off  all  carbon,  it  is  allowed  to  cool,  and  then 
examined.  If  at  all  purple,  gold  is  present  in  the 
ore,  and  the  relative  amount  may  be  approximately 
deduced  as  much,  fair,  little  or  none.  There  is  no 
compound  which  would  be  formed  from  natural 
products  by  this  method  which  would  mislead  by 
staining  the  ash  to  a  color  at  all  similar  to  the  dis- 
tinctive purple  of  finely-divided  gold. 

A  variation  of  this  test  is  given  by  Thorpe  and 
Muir  in  "  Qualitative  Chemical  Analysis  "  as  follows: 

Five  or  ten  grains  of  the  finely  powdered  mineral 
are  shaken  with  alcoholic  tincture  of  iodine,  pre- 
pared by  dissolving  J  oz.  of  iodine  and  J  oz.  of 
iodide  of  potassium  in  1  pint  of  rectified  spirit. 

The  insoluble  matter  is  allowed  to  settle,  a  piece 
of  Swedish  filter  paper  is  dipped  into  the  solution 
and  incinerated  after  drying.  If  the  ash  be  purple 
in  color,  gold  is  present.  To  confirm  the  presence 
of  gold,  treat  the  ash  with  a  few  drops  of  aqua 
regia,  evaporate  to  dryness  at  a  gentle  heat,  and 
dissolve  the  residue  in  water.  Pour  this  solution 
into  a  beaker  which  is  set  upon  a  sheet  of  white 
paper.  A  solution  is  now  prepared  by  adding  ferric 
chloride  to  stannous  chloride  until  a  permanent 
yellow  color  is  produced.  This  solution  is  diluted, 
a  glass  rod  is  dipped  into  it,  then  into  the  gold 
solution.  A  bluish  purple  streak  in  the  track  of 
the  rod  confirms  the  presence  of  gold. 

Occurrence  of  Gold  in  other  Forms.  Beside  in  the 
condition  of  simple  native  gold,  this  metal  is  found, 


124      prospector's  field-book:  and  guide. 

as  previously  mentioned,  in  intimate  mixture  with 
pyrite  (iron  sulphide).  It  does  not  seem  to  be  a 
compound,  but,  as  we  have  said,  a  mixture  or 
minute  association.  This  seems  evident  from  the 
fact  that  when  the  sulphur  is  removed  from  the 
pyrite  and  the  iron  rusts  down,  the  gold  particles 
appear  with  their  own  color  and  characteristics  in 
cavities  of  various  rocks,  which,  when  crushed  or 
water-worn,  release  the  particles  or  pieces  to  be 
washed  down  and  mingled  with  sands  and  gravels 
of  lower  levels,  or  perhaps  the  beds  and  channels 
of  rivers.  This  is  "  placer  gold."  Where  gold  has 
not  yet  been  thus  released,  it  is  found  in  association 
with  iron,  and  especially  with  quartz  in  veins.  In 
some  instances  the  gold  in  quartz  is  disseminated 
in  particles  so  exceedingly  fine  as  to  require  the 
lens  to  reveal  it. 

Nevertheless  quartz  is  not  the  only  mineral  which 
contains  gold,  although  it  is  the  world's  great  pay- 
ing source  of  gold.  Some  of  the  other  minerals 
contain  it.  It  is  found  in  yellowish-white,  four-sided 
prisms,  and  in  small  white  grains  as  large  as  a  pea, 
and  easily  crumbles.  In  this  condition  the  gold  is 
amalgamated  with  quicksilver  in  the  proportion  of 
38  gold  to  57  quicksilver,  and  is  known  as  "gold 
amalgam."  It  is  very  easily  tested  by  heating  upon 
a  piece  of  charcoal  by  a  blow-pipe,  when  the  quick- 
silver volatilizes  and  the  gold  remains. 

Gold  in  paying  quantities  is  found  in  numerous 
combinations,  and  must  be  discovered  and  extracted 
either  chemically,  by  the  "  wet  method,"  or  by  assay- 


GOLD.  125 

ing  in  the  crucible  by  means  of  the  cupel  and  fur- 
nace, when  it  cannot  be  separated  on  the  spot  by  the 
blow-pipe.  These  methods  are  taught  in  any  book 
upon  the  assay  of  gold. 

Geology  of  Gold.  Native  gold  is  found,  when 
in  situ,  with  comparatively  small  exceptions,  in  the 
quartz  veins  that  intersect  metamorphic  rocks,  and 
to  some  extent  in  the  wall-rock  of  these  veins.  The 
metamorphic  rocks  thus  intersected  are  mostly 
chloritic,  talcose  and  argillaceous  schists  of  dull 
green,  dark  grey,  and  other  colors ;  also  much  less 
commonly  mica  and  hornblende  schist,  gneiss, 
diorite,  porphyry,  and  still  more  rarely  granite.  A 
laminated  quartzite  called  itacolumite  is  common  in 
many  gold  regions,  and  sometimes  specular  schists 
or  slaty  rocks,  containing  much  foliated  specular 
iron  (hematite)  or  magnatite  in  grains. 

The  gold  occurs  in  the  quartz  in  strings,  scales, 
plates,  and  in  masses  which  are  sometimes  an 
agglomeration  of  crystals.  The  scales  are  often 
invisible  to  the  naked  eye,  massive  quartz  that 
apparently  contains  no  gold  frequently  yielding  a 
considerable  percentage  to  the  assay er.  It  is  always 
very  irregularly  distributed,  and  never  in  con- 
tinuous pure  bands  of  metal  like  many  metallic 
ores.  It  occurs  both  disseminated  through  the 
mass  of  the  quartz  and  in  its  cavities. 

In  studying  the  geological  aspects  of  this  subject 
and  making  the  practical  application  of  our  knowl- 
edge to  the  search,  it  may  be  stated  that  the 
original  position  of  gold  must  have  been  in  great 


126      prospector's  field-book  and  guide. 

depths.  From  these  depths  it  has  been  brought  up 
by  the  upheaval  of  the  granitic  rocks  and  perhaps, 
along  with  basaltic  and  other  intrusions  shot  up 
from  immense  depths.  In  the  course  of  ages  the 
attrition  and  breaking  down  of  these  higher  or  up- 
lifted levels,  and  the  long-continued  floods,  rains 
and  the  waves  of  ancient  oceans  and  other  disinte- 
grating forces  which  produced  the  sedimentary 
rocks,  at  the  same  time  liberated  the  gold  which 
was  incapable  of  decomposition.  The  gold  thus 
found  new  and  varied  resting  places  in  the  sedi- 
mentary rocks  of  various  ages,  and  in  all  the  condi- 
tions which  the  surface  might  assume. 

The  quartz  rocks  are  neither  igneous  nor  sedimen- 
tary, but  are  supposed  to  have  been  in  liquid  form 
as  solutions  of  silex,  which,  during  long  periods  of 
time,  graduaily  deposited  the  silex  and  whatever 
they  contained,  the  water  disappearing  by  evapora- 
tion or  absorption. 

Frequently,  cellular  quartz  has  been  found  with 
gold  within  the  cells,  the  material  which  surrounded 
the  gold  having  become  decomposed,  and,  thus 
releasing  the  undecomposed  gold,  the  latter  is  found 
in  the  cells  of  the  quartz. 

Gold,  therefore,  is  to  be  expected  and  looked  for 
in  granitic  regions  (Fig.  46),  and  in  those  rocks  and 
from  those  gravels  and  sands  which  owe  their  origin 
to  such  regions.  It  requires  much  judgment,  gen- 
eral exploration,  and  knowledge  of  the  region  before 
the  prospector  can,  with  probability,  expect  to  meet 
with  gold,  or  before  he    should  begin  the  search. 


GOLD.  127 

But  with  a  full  knowledge  of  the  geologic  condition 
of  the  country,  and  acting  in  accordance  with  the 
above  facts,  the  prospector  will  soon  come  upon 
traces  of  gold,  if  any  exist. 

In  looking  for  indications,  the  prospector  should 
never  pass  an  ironstone  "  blow-out"  without  ex- 
amination, as,  according  to  the  German  aphorism, 
"  the  iron  hat  covers  the  golden  head,"  or  as  the 

Fig.  46. 


Section  showing  the  two  conditions  under  which  gold  is  usually  found  in  rock  and 

drift. 
The  Structure  of  the  Ural  Mountains.— a.  Granitic  and  gneiss  rocks 
penetrated  with  greenstones  and  porphyrytic  rocks  containing  gold  finely 
disseminated,  b.  Micaceous,  talcose,  and  argillaceous  slaty  rocks,  snpposed 
to  be  Laurentian  and  Cambrian,  c.  Silurian  and  Devonian  strata,  d.  Car- 
boniferous, limestone  and  grits,  e.  Coal  measures.  /.  Permian  and  newer 
rocks.  O,  G,  O  G.  Drift,  filling  hollows  in  rocks  with  gold,  especially  at  the 
base  of  the  drift. 

Cornishman  puts  it,  "  iron  rides  a  good  horse." 
The  ironstone  outcrop  may  cover  a  gold,  silver, 
copper  or  tin  lode. 

Besides  the  general  instructions  given  above,  con- 
siderable study  should  be  devoted  to  the  peculiar 
and  seemingly  irregular  deposits  of  gold  where  it 
does  not  appear  to  have  been  washed  down  from  any 
higher  levels.     For  instance,  in  California  and  some 


128      prospector's  field-book  and  guide. 

other  districts  free  gold  has  been  found  in  drifts  and 
sand  and  in  the  beds  of  streams  which  have  not 
only  been  filled  up,  but  have  been  buried  under 
regions  of  sandstone  or  other  rocks,  but  the  whole 
country  has  apparently  been  raised,  or  the  sur- 
rounding region  has  sunk  so  as  not  to  show  any 
very  considerable  elevation  beyond  where  the  gold 
deposits  have  been  formed.  But,  even  in  this  case, 
the  general  rule  has  been  shown  to  be  correct,  for 
these  deposits  have  been  proved  to  be  in  the  beds 
or  channels  of  ancient  rivers,  which  had  either  been 
dried  up  and  overflowed  by  vast  eruptions  of  lava 
or  basalt,  and  again  by  floods  bringing  new  soil  and 
creating  sedimentary  rock,  or  the  country  has  been 
raised,  or  subsidence  of  a  great  extent  of  land  has 
taken  place.  In  many  cases,  however,  no  sub- 
sidence has  occurred,  but  only  overflow  and  filling 
up  through  ages,  and  the  actual  sources  still  remain 
elevated. 

Such  events  as  we  have  just  described  do  not 
transpire  without  leaving  in  some  parts,  traces  or 
features  or  material,  which,  to  the  practiced  eye 
of  a  skillful  prospector,  are  evidences  of  some  such 
movements  and  changes,  and  he  may  proceed  to 
make  a  successful  opening  only  after  he  has  care- 
fully examined  a  large  tract  of  country,  for  it  is 
from  extended  survey  that  he  may  the  more  wisely 
judge  of  the  relation  of  superficial  parts  to  the 
greater  depths  of  even  small  areas. 

Those  rocks  which  lie  more  immediately  over  the 
granite,  and  which,  although  they  owe  their  origin 


GOLD.  129 

to  a  sedimentary  condition,  have  been  subjected  to 
heat  and  heated  waters,  as  is  supposed,  we  have 
called  "  metamorphic  rocks."  But  they  have  been, 
probably,  first  formed  from  the  disintegration  of  the 
most  ancient  rocks,  and  have  brought  with  them 
fragments  of  gold.  These  metamorphic  rocks  have 
been  changed  from  ordinary  sedimentary  rock  by 
the  action  of  heat  and  by  pressure,  and  the  influence 
of  such  treatment  may  be  suspected  by  their  appear- 
ance being  crystalline  in  their  composition  ;  that 
is,  the  fine  grains  which  compose  them,  as  well  as 
the  larger  grains,  are  angular,  whereas  the  materials 
of  purely  sedimentary  rocks  are  fine  without  angular 
shape.  The  larger  part  of  granite  is  supposed  to 
have  been  metamorphic  or  changed,  as  the  word 
means,  or  "  altered  "  merely  by  the  action  of  heat 
into  a  crystalline  form  or  mass. 

The  igneous  rocks  are  those  whose  forms  are  due 
to  having  been  melted  and  driven  to  the  surface 
through  fissures  in  the  overlying  rocks.  They  are 
variously  composed  of  feldspar,  hornblende,  a  little 
quartz,  with  comparatively  small  proportions  of 
other  substances,  and  are  called  by  various  names 
according  to  the  composition.  The  metamorphic 
granite  contains  quartz,  feldspar,  and  mica;  the 
igneous  granite  contains  little  or  no  quartz.  Syenite- 
granite  contains  hornblende  in  place  of  mica.  Some- 
times the  mica  is  very  black,  as  hornblende  is,  and 
in  that  case  may  be  distinguished  from  the  latter 
by  its  more  easy  cleavage,  as  we  have  shown,  under 
a  sharp  pen-knife ;  this  black  mica  is  the  kind  we 
9 


130      prospector's  field-book  and  guide. 

have  described  as  biotite  (p.  31).  There  is  a  syenite 
which  contains  no  quartz,  called  hyposyenite.  These 
rocks  are  not  the  original  home  of  gold,  but  at  pres- 
ent it  is  very  largely  in  these  metamorphic  rocks 
that  the  most  paying  gold  is  to  be  found,  more 
especially  in  the  quartz  veins  which  have  intersected 
these  rocks.  One,  therefore,  of  the  most  important 
studies  of  the  prospector  is  to  acquaint  himself 
familiarly  with  the  appearance,  the  locations,  and 
the  departures  of  these  metamorphic  rocks.  In 
many  places  where  the  alluvial  gold,  derived  from 
the  gold-bearing  gravels,  has  almost  ceased  to  be 
worth  working,  there  still  remain  sources  undis- 
covered, and  these  sources  may  probably  be  traced 
back  even  yet  to  some  out-crop  or  to  some  ancient 
elevation  now  having  subsided. 

The  above  remarks  are  applicable  to  explorations 
for  other  metallic  ores  than  gold.  They  apply  to 
silver,  and  especially  to  tin  ores,  and  with  some 
modifications,  to  copper  ores  and  to  quicksilver,  as 
we  shall  show. 

Gold  in  combination.  We  have  been  speaking 
of  gold  as  native  and  alone.  But  it  must  not  be 
thought  that  this  condition  is  the  only  one  in  which 
paying  gold  is  found.  The  combinations  of  gold 
with  various  oxides  and  sulphides  of  other  metals 
are  very  valuable,  and  should  be  studied. 

In  almost  all  gold-bearing  regions  the  iron  sul- 
phides carry  much  gold,  and  in  some  regions  the 
paying  gold  is  found  only  in  this  substance.  Hence, 
it  is  well  for  the  prospector  to  determine  the  pres- 


GOLD.  131 

ence  of  gold  in  the  pyrite  or  whatever  sulphide  may 
present  itself.  We,  therefore,  state  a  method  or 
two  of  determining  the  fact  that  gold' exists  in  this 
substance. 

1.  To  separate  gold  in  metallic  sulphides,  for  in- 
stance, iron  pyrites.  Powder  the  sulphide  as  finely 
as  possible.  Put  about  an  ounce  into  a  Hessian 
crucible  and  heat  to  a  very  low  red  heat  for  an 
hour,  or  until  there  is  very  little  escape  of  sulphur 
fumes.  Remove  the  crucible  and  put  its  contents 
into  a  porcelain  dish.  Pour  over  the  roasted  pow- 
der three  fluidounces  of  strong  nitric  acid,  by  drops, 
until  all  violent  action  ceases.  Add  water,  8  or  10 
fluidounces ;  the  gold,  if  any,  will  appear  as  a  very 
fine  black  powder ;  filter  and  dry,  pick  out  a  small 
particle  of  the  powder  and  mash  it  upon  a  hard 
surface,  iron  or  agate,  in  an  agate  mortar ;  if  it  is 
gold,  it  will  show  the  gold  color.  A  sufficient 
quantity  of  the  dried  powder  may  be  placed  upon 
a  piece  of  charcoal,  and  by  means  of  either  0  or  I 
flame  of  the  blow-pipe  it  may  be  melted,  and  both 
by  its  color  and  softness  be  proved  to  be  gold. 

There  is  a  difficulty  in  this  process  which  the 
prospector  may  not  be  able  easily  to  overcome,  and 
that  is  the  necessity  of  using  the  strongest  nitric  acid. 
If  he  has  a  little  laboratory  he  may  readily  make 
his  own  nitric  acid  of  sufficient  power,  and  then  he 
possesses  the  simplest  and  quickest  method  of  treat- 
ing sulphides  or  any  gold-bearing  pyrites.  The 
process  is  as  follows  :  This  acid  may  be  made  from 
common  saltpetre  and  sulphuric  acid  of  commerce, 


132      prospector's  field-book  and  guide. 

Dry  the  saltpetre  after  breaking  it  into  small  lumps 
of  a  half  inch  in  diameter,  carefully  drop  the  lumps 
into  a  glass  retort,  hang  the  retort  on  a  wire  or 
stand,  and  introduce  the  beak  into  a  glass  bottle. 
Place  the  bottle  in  a  basin  of  cold  water  and  you 
may  now  apply  the  heat  of  a  lamp,  keeping  the 
flame  low  and  five  or  six  inches  off  from  the  bottom 
of  the  retort.  A  coal-oil  lamp  with  a  short  chimney 
may  be  used,  and  the  heat  regulated  to  a  point  at 
which  brownish  vapors  appear  in  the  retort.  Keep 
enough  acid  in  the  retort  to  barely  cover  the  salt- 
petre, and  keep  cool  water  in  the  basin,  and  the 
vapors  come  over  and  condense  without  much 
trouble. 

Stop  the  operation  when  the  vapors  cease  to  come 
over,  and  the  mass  in  the  retort  seems  to  settle  down 
to  an  even  surface.  Then  draw  out  the  beak  of  the 
retort  and  put  the  glass  stopper  into  the  bottle,  and 
keep  the  bottle  away  from  light  and  heat.  Wash 
out  the  retort,  and  if  you  require  more  nitric  acid, 
renew  the  operation.  The  retort  should  be  tubu- 
lated to  allow  of  adding  sulphuric  acid  during  the 
operation  if  needed. 

This  acid  is  a  yellowish-brown  liquid  and  is 
known  as  "  fuming  nitric  acid,"  and  is  one  of  those 
very  active  and  convenient  aids  in  the  laboratory 
which  cannot  readily  be  purchased,  and,  therefore, 
must  generally  be  made  ;  but  so  little  of  it  may  be 
used  that  a  small  quantity  goes  a  great  way,  and  it 
will  effect  a  result  which  the  strongest  and  purest 
chemically-pure    nitric    acid  fails  to  produce.     Its 


GOLD.  133 

effect  is  to  release  the  gold  from  the  combination  of 
iron  and  sulphur  by  oxidizing  the  latter  as  well  as 
the  former,  and  rendering  them  soluble  in  water, 
while  the  gold  remains  in  metallic  form  of  an  ex- 
ceedingly fine  black  powder,  as  has  been  said. 

2.  Another  method  of  detecting  and  separating 
the  gold,  where  the  above  one  cannot  be  used,  is 
by  pulverizing  the  sulphide  ore  very  finely  and  mix- 
ing it  with  three  or  four  times  its  weight  of  caustic 
potash  or  caustic  soda,  and  then  subjecting  the 
crucible,  which  contains  the  mixture,  to  a  low  red 
heat  till  all  the  contents  cease  agitation  and  become 
perfectly  tranquil.  Then  remove  the  crucible,  wait 
till  all  is  cool,  and  then  add  hydrochloric  (muriatic) 
acid  in  an  amount  equal  to  three  or  four  times  the 
bulk  of  the  mass.  To  this,  after  standing  three  or 
four  hours  in  a  warm  place,  add  the  usual  nitric 
acid  (about  an  ounce),  after  transferring  all  the 
liquid  to  a  porcelain  dish,  or,  next  best,  to  a  beaker- 
glass.  Let  it  stand  in  a  warm  place  for  about  an 
hour,  then  add  a  little  more  nitric  acid  (about  half  an 
ounce),  stir  it  well  with  a  glass  rod  or  strip  of  glass, 
and  let  it  stand  again  for  an  hour  or  two.  Examine 
carefully,  and  if  it  seems  to  have  been  dissolved 
more  thoroughly  than  before,  add  a  little  more 
nitric  acid  and  warm  again,  stirring  well  as  before. 
If  no  more  seems  to  be  dissolved,  then  filter  and 
wash  the  sediment  in  the  filter  and  let  it  dry,  and 
remove  the  filter  and  contents  for  further  examina- 
tion. Now  precipitate  the  gold  from  the  filtrate  by 
pouring  into  it  a  solution  of  ferrous  sulphate.     [Any 


134        PROSPECTOR?S    FIELD-BOOK    AND    GUIDE. 

clear  green  crystals  of  "  copperas  "  (sulphate  of  iron) 
of  the  drug  store,  filtered,  after  saturated  solution 
in  clean  rain-water  and  kept  in  corked  bottles,  will 
answer  this  purpose.]  Let  the  solution  stand  in  a 
warm  place  for  an  hour,  drop  in  a  few  more  drops, 
and  if  any  further  precipitation  takes  place,  add 
half  an  ounce  of  the  sulphate,  stir  it  again,  let  it 
remain  an  hour  longer  in  a  warm  place  till  all  pre- 
cipitation ceases.  Decant  the  supernatant  clear 
water  and  transfer  the  remainder  to  a  filter-paper 
carefully,  and  a  little  at  a  time,  to  avoid  breaking 
the  filter-paper,  then  rinse  the  porcelain  dish  to  get 
all  particles  upon  the  filter-paper,  and  when  all  the 
liquid  has  passed  through,  let  it  dry,  and  remove 
all  the  contents  of  the  paper  to  a  small  porcelain 
capsule  or  crucible,  and  apply  the  heat  of  the  blow- 
pipe to  burn  off  the  paper  or  any  organic  substance 
which  may  have  got  into  the  powder ;  the  gold 
remains,  which  may  be  gathered  upon  charcoal  and 
melted  into  a  globule  by  the  concentrated  flame  of 
the  blow-pipe,  if  in  small  quantity.  Lastly,  ex- 
amine the  contents  of  the  filter  which  was  laid 
aside ;  and,  if  any  appearance  of  gold  is  noted, 
separate  it  under  examination  by  a  pocket  lens. 

The  high  value  of  gold  renders  even  a  grain  of 
gold  to  the  pound  of  ore,  if  that  pound  is  an  aver- 
age pound  in  the  ton,  worth  $80  to  the  ton  of  2000 
pounds.  Hence,  a  pyrites  which  contains  a  half 
grain  to  the  half  pound  may  prove  too  valuable  to 
neglect.  In  the  Brazils,  in  deep  mines,  the  ore 
yields  only  half  an  ounce  to  the  ton  of  ore,  and  yet 


GOLD.  135 

it  is  mined  at  a  profit.*  In  California,  a  continuous 
yield  of  three-eighths  to  half  an  ounce  of  gold  to  the 
ton  of  quartz  is  considered  profitable  working.! 

It  must  be  remembered,  however,  that  the  above 
process  of  extracting  the  gold  from  a  pyritous  ore 
does  not  extract  with  perfect  accuracy  all  the  gold 
unless  conducted  with  more  care  and  time  than  we 
have  suggested,  but  it  is  sufficient  to  reveal  the  fact 
that  the  ore  is  valuable. 

3.  The  following  method  requires  more  time  and 
care  and  the  use  of  a  little  furnace,  but  will  give 
very  accurate  results.  Pulverize  the  ore  supposed 
to  contain  any  gold,  whether  pyrites  or  not.  Heat 
it  in  a  crucible  very  gradually  at  first,  increasing 
the  heat  to  drive  off  as  much  sulphur  as  possible, 
frequently  stirring  it  and  increasing  the  heat  till 
all  fumes  seem  to  have  escaped.  Withdraw  it  and 
prepare  a  crucible  (clay  or  Hessian  crucible),  by 
dipping  it  in  a  strong  solution  of  borax  in  water, 
and  heating  the  crucible  and  repeating  the  dipping 
and  heating  till  the  crucible  shows  a  glazed  inside. 
Then  transfer  all  the  roasted  powdered  ore,  after 
weighing  it  (if  you  desire  relative  quantity),  into 
the  crucible,  and  cover  it  with  the  following  mixture 
(called  a  flux) :  Six  times  the  weight  of  ore  of  lith- 
arge, one  of  dry  borax,  and  about  twenty  grains  of 
charcoal  pulverized.  Heat  slowly  at  first,  not  al- 
lowing much  foaming,  until  all  is  quiet  and  the 

*Makins'  Metallurgy,  p.  227. 

t  Da  vies'  Metalliferous  Minerals  and  Mining,  p.  64. 


136      prospector's  field-book  and  guide. 

metal  button  settles  down  at  the  bottom  of  the  cru- 
cible. Cool  and  break  the  crucible  to  extract  the 
button  of  metal,  which  is  now  ready  for  cupelling. 
{For  this  process  see  p.  98.) 

Any  one  of  these  three  methods  of  separating  all 
the  usual  ores  may  readily  be  employed,  and  a  little 
practice  will  enable  the  operator  to  be  expert  in 
their  use.  A  great  deal  more  depends  upon  the 
skill  of  the  operator  than  upon  the  cost  of  his 
appliances. 

It  has  not  been  thought  necessary  to  give  a  list  of 
places  in  the  world  where  gold  has  been  found,  but 
in  view  of  the  excitement  created  by  the  rich  finds  of 
gold,  in  July,  1897,  in  the  Klondike  district,  Alaska, 
it  may  be  of  interest  here  to  give  a  brief  description 
of  the  Yukon  gold  district,  which  besides  the  Klon- 
dike, comprises  the  Hootalinqua,  Stewart,  MacMil- 
lan,  Forty-Mile,  Sixty-Mile,  Birch  Creek,  Munook 
Creek,  Tanana  and  Koyukuk  districts. 

Throughout  nearly  the  whole  of  Alaska  gold  is 
found  disseminated  in  the  detritus  which  has  been 
derived  from  the  abrasion  of  the  solid  rocks.  Often 
it  is  in  such  small  amounts  that  it  cannot  be  pro- 
fitably extracted,  but  sometimes  it  is  concentrated 
by  water  action  in  such  a  degree  as  to  invite  min- 
ing. Thus  far  the  profitable  deposits  have  all  been 
found  in  or  near  the  beds  of  the  present  streams. 
These  recent  gravels  may  be  divided  into  two  chief 
classes.  In  the  larger  streams  accumulations  of 
gravel  are  made  in  places  of  slackening  current? 
such  as  the  inner  or  concave  sides  of  curves.     These 


GOLD.  137 

accumulations  are  called  bars,  and  often  contain 
much  gold.  The  other  occurrence  is  in  the  small 
gulches  which  feed  the  larger  streams.  In  the  bot- 
tom of  the  gulches  the  gravels  are  frequently  very 
rich  in  gold,  and  as  these  are  easily  worked,  they 
constitute  at  the  present  time  the  most  important 
class  of  placer  deposits. 

The  gold  of  the  Yukon  district  is  chiefly  derived 
from  quartz  veins,  which  are  found  most  abund- 
antly in  the  schists  of  the  Forty-Mile  and  the  Birch 
Creek  series,  although  not  infrequently  in  the  igne- 
ous and  pyroclastic  rocks  of  the  Rampart  series.  It 
is  also  derived,  although  to  a  far  less  extent,  from 
impregnated  shear  zones,  which  occur  especially  in 
the  Rampart  series.  Of  the  quartz  veins  one  set  is 
sheared  and  one  unsheared.  The  first  is  difficult  to 
follow,  for  the  veins  are  broken  and  non-persistent. 
The  veins  of  the  second  set  are  often  persistent  and 
wide,  and  in  some  cases  may  be  mined  profitably. 
Impregnations  along  shear  zones  may  also  in  some 
cases  be  sufficiently  rich  in  metallic  minerals  to 
form  ores  under  favorable  conditions  ;  and  the  rock 
in  the  region  of  these  shear  zones  is  often  unfaulted, 
so  that  these  ore  bodies  may  be  expected  to  be  com- 
paratively persistent. 

The  quartz  veins  are  connected  with  dikes,  chiefly 
light-colored  crystalline  rocks  such  as  granite  and 
aplite.  This  should  be  kept  in  mind  in  prospecting, 
and  auriferous  veins  may  be  looked  for  in  the  schists 
near  the  dikes.  In  some  cases,  although  not  so 
commonly,  they  may  also  occur  at  some  distance 
from  a  dike. 


138      prospector's  field-book  and  guide. 

These  gold-bearing  rocks  form  a  definite  belt, 
extending  in  a  general  way  from  the  lower  Ram- 
parts of  the  Yukon  and  below  to  Dease  Lake  and 
other  mining  districts  in  British  Columbia,  a  dis- 
tance in  a  straight  line  of  about  a  thousand  miles. 
Of  this  distance,  400  or  500  miles  is  in  American 
territory.  The  width  of  the  belt  varies  chiefly  with 
the  minor  folding,  v/hich  has  accompanied  the 
greater  plications.  In  this  belt  not  only  the  gold- 
bearing  veins,  but  the  richest  placers  are  found. 
This  is  naturally  the  case,  since  the  gold  in  these 
placers  is  worn  out  of  the  solid  rocks.  It  is  espec- 
ially true  that  the  rich  gulch  gravels  are  in  this 
belt,  and  also  the  most  paying  bar  gravels,  although 
fine  gold  in  some  cases  may  be  carried  somewhat 
outside  the  belt,  and  may  be  sufficiently  concen- 
trated in  favorable  situations  to  pay  for  washing. 

The  Birch  Creek,  the  Forty  Mile  and  the  Klon- 
dike districts  are  all  in  this  belt,  and  are  all  in  the 
schistose  rocks,  and  in  these  rocks  new  deposits 
of  value  may  be  looked  for.  Some  placer  diggings 
of  value  may  also  be  found  in  the  rocks  of  the 
Rampart  series,  but  as  a  rule  higher  horizons  are 
.probably  barren,  save  in  exceptional  cases.  Con- 
glomerate made  up  of  the  detritus  from  the  schis- 
tose Birch  Creek  and  Forty  Mile  rocks  should  be 
prospected,  however,  since  they  may  prove  to  be 
fossil  placers.  Ancient  gravels  lying  above  the 
present  stream  channels  should  also  be  kept  in 
mind,  for  they  may  in  places  contain  sufficient  gold 
to  be  profitably  mined. 


GOLD.  139 

Rule  for  ascertaining  the  amount  of  gold  in  a  lump 
of  auriferous  quartz,  according  to  Phillips  : 

The  specific  gravity  of  gold  is  19.000. 

The  specific  gravity  of  quartz  is  2.600. 

These  numbers  are  given  here  merely  for  conven- 
ience in  explaining  the  rule  ;  they  do  not  accurately 
represent  the  specific  gravities  of  all  quartz  and 
quartz  gold.  (The  quartz  gold  of  California  has 
not,  on  an  average,  a  specific  gravity  of  more  than 
18.600.) 

1.  Ascertain  the  specific  gravity  of  the  lump. 
Suppose  it  to  be  8.067. 

2.  Deduct  the  specific  gravity  of  the  lump  from 
the  specific  gravity  of  the  gold  ;  the  difference  is 
the  ratio  of  the  quartz  by  volume :  19.000 — 8.067 
=  10.933. 

3.  Deduct  the  specific  gravity  of  the  quartz  from 
the  specific  gravity  of  the  lump  ;  the  difference  is 
the  ratio  of  the  gold  by  volume :  8.067—2.600  = 
5.467. 

4.  Add  these  ratios  together  and  proceed  by  the 
rule  of  proportion.  The  product  is  the  percentage 
of  gold  by  bulk  :  10.933  +  5.467  =  16.400.  Then, 
as  16.400  is  to  5.467,  so  is  100  to  33.35. 

5.  Multiply  the  percentage  of  gold  in  bulk  by  its 
specific  gravity.  The  product  is  the  ratio  of  the 
gold  in  the  lump  by  weight :  33.35  x  19.00  = 
643.65. 

6.  Multiply  the  percentage  of  quartz  by  bulk 
(which  must  be  66.65,  since  that  of  gold  is  33.35) 
by  its  specific  gravity.     The  product  is  the  ratio 


140      prospector's  field-book  and  guide. 

of  the  quartz  in  the  lump  by  weight :  66.65  x  2.60 
=  173.29. 

7.  To  find  the  percentage,  add  these  two  ratios 
together  and  proceed  by  the  rule  of  proportion  : 
633.65  +  173.29  =  806.94.  Then  as  806.94  is  to 
633.65,  so  is  100  to  78.53.  Hence,  a  lump  of  aurif- 
erous quartz  having  a  specific  gravity  of  8.067,  con- 
tains 78.53  per  cent,  of  gold  by  weight.  (The 
Mines,  Miners,  and  Mining  Interests  of  the  United 
States  in  1882,  by  Win.  Ralston  Balch,  Phila.,  p. 
761.) 


CHAPTER  VII. 

TELLURIUM,  PLATINUM,  SILVER. 

Tellurium  Minerals.  Tellurium  is  the  only 
metal  which  has  hitherto  been  found  in  nature  in 
actual  chemical  combination  with  gold.  It  also 
occurs  in  a  native  state,  and,  combined  with  other 
metals,  forming  tellurides.  The  tellurides  com- 
prise a  small  but  interesting  group,  and  occur  under 
similar  conditions  of  association  in  a  few  widely 
separated  localities,  the  more  abundant  ores  being 
of  great  economic  value,  as  containing  a  large  pro- 
portion of  gold  and  silver.  The  most  important  of 
these  are  given  below,  but  tellurides  of  mercury, 
bismuth,  lead,  and  nickel  also  exist. 

lellurium  has  a  bright  tin-white  color  and  a 
metallic  lustre.  It  is  brittle  and  very  fusible,  vola- 
tilizing almost  entirely  and  tinging  the  blow-pipe 
flame  green.  White  coating  on  charcoal.  Soluble 
in  nitric  acid.     Rare. 

Nagyagite,  foliated  or  black  tellurium.  Streak, 
blackish  lead-gray.  Color,  blackish  lead-gray. 
Lustre,  metallic.  Sectile,  flexible  in  thin  lamina?. 
Occurs  in  granular  or  foliated  masses.  If  the 
mineral  is  treated  for  sometime  in  the  0.  F.  a 
malleable  globule  of  gold  remains.  This  cupelled 
with  a  little  assay  lead  assumes  a  pure  yellow  color. 
(141) 


142      prospector's  field-book  and  guide. 

Nagyagite  forms  a  valuable  gold  ore  in  Nagyag, 
Transylvania. 

Hessite.  Streak,  iron  black.  Color,  lead  to  steel 
gray.  Lustre,  metallic.  Sectile,  brittle.  Forms 
cubic  masses  of  fine-grained  texture.  Before  the 
blow-pipe  fuses  on  charcoal  to  a  black  globule  ;  this 
heated  in  R.  F.  presents  on  cooling  white  dendritic 
prints  of  silver  on  its  surface  ;  with  soda  is  reduced 
to  a  globule  of  silver. 

Petzite.  Color,  steel  gray,  iron  black,  sometimes 
peacock  tarnish.  Lustre,  metallic.  Sectile,  brittle. 
Forms  cubic  masses  of  fiue-grained  texture,  like 
hessite,  which  it  resembles  in  most  physical  char- 
acters, but  is  much  denser.  In  one  locality  in 
Colorado  it  forms  one  of  the  principal  minerals  in  a 
group  of  quartz  veins  in  porphyries  traversing  very 
coarse  granites,  and  occurs  in  rounded  masses, 
sometimes  implanted  on  iron  pyrites  and  irregular 
crystalline  aggregates,  which  are  occasionally  coated 
with  encrusting  pseudomorphs  of  gold.  Some 
varieties  giving  18  per  cent,  of  gold  have  a  specific 
gravity  of  8  to  8.3  ;  others  giving  24  to  26  per  cent, 
of  gold  have  a  specific  gravity  of  9  to  9.4. 

Sylvanite  or  graphic  tellurium.  Streak,  steel  gray 
to  silver  white.  Color,  steel  gray  to  silver  white, 
and  sometimes  nearly  brass  yellow.  Lustre,  metal- 
lic. Sectile,  brittle  in  thin  laminse.  Colors  the 
flame  blue  or  bluish  green,  giving  a  white  incrusta- 
tion and  a  dark  gray  bead  which  can  be  reduced 
alone  after  long  blowing,  or  more  quickly  with 
soda,  to  a  yellow  malleable,  metallic  bead  of  silvery 


TELLURIUM,  PLATINUM,  SILVER.  143 

gold.  The  proportion  of  gold  to  silver  varies.  In 
California  sylvanite  occurs  in  narrow  veins  travers- 
ing porphyry.  It  is  called  graphic  because  of  the 
resemblance  in  the  arrangement  of  the  crystals  to 
writing  characters. 

Tellurides  constitute  exceedingly  valuable  ores 
when  they  are  sufficiently  rich  to  allow  of  hand 
picking  and  sale  to  smelters,  and  even  the  poorer 
ores  can  be  treated  by  roasting  and  either  chlorina- 
tion  or  cyanidation.  In  many  cases  attempts  to 
concentrate  have  been  unsatisfactory,  as  the  mineral 
frequently  slimes  a  great  deal ;  but  concentration  is 
said  to  have  been  successfully  applied  in  Boulder 
County,  Colorado,  and  the  possibility  depends  to  a 
great  extent  upon  the  nature  of  the  ore.  Specimens 
are  found  .in  many  localities,  but  it  is  in  compara- 
tively few  places  that  workable  deposits  exist. 

Platinum  occurs  native  and  in  flattened  or 
angular  grains  or  nuggets  which  are  malleable. 
Its  color  and  streak  are  steel-gray,  Lustre  metallic 
bright.  Isometric,  but  is  seldom  found  in  crystals. 
Hardness  4  to  4.5.  Specific  gravity  16  to  19.  As 
heavy  as  gold,  and,  therefore,  easily  distinguished 
and  separated  from  lighter  materials.  Before  the 
blow-pipe  it  is  infusible ;  not  affected  by  borax,  ex- 
cept when  containing  some  metal,  as  iron  or  copper, 
which  gives  the  reaction.  Soluble  only  in  heated 
nitro-muriatic  acid. 

Platinum  is  occasionally  found  in  the  gold-bear- 
ing gravels  of  California  and  Oregon,  but  the  an- 
nual production  is  small.     There  are  no  means  of 


144 

knowing  whether  it  is  present  in  sufficient  abund- 
ance for  separate  mining.  The  prospectors,  as  a 
rule,  do  not  know  the  value  of  the  black  sand,  nor 
are  they  always  able  to  distinguish  it  from  less  val- 
uable ores  ;  and  it  is,  therefore,  not  unlikely  that 
deposits  may  yet  be  found. 

The  supply  of  platinum  comes  chiefly  from 
Russia,  where  it  occurs  in  gravels,  probably  origin- 
ally auriferous,  on  the  Siberian  side  of  the  Ural. 
Since  serpentine  is  usually  near  at  hand,  and  the 
placers  increase  in  richness  as  the  rock  is  ap- 
proached, and  since  the  metal  has  been  found  in 
this  rock,  it  seems  probable  that  this  is  the  source. 
This  mode  of  occurrence  of  platinum  and  the  asso- 
ciation with  serpentiferous  rocks  prevails  also  in 
other  platinum-producing  regions.  Platinum  is 
always  alloyed  with  the  other  metals  of  the  plat- 
inum group,  iridium,  osmium,  palladium,  etc.,  and 
with  iron,  the  amount  of  platinum  varying  from 
50  to  80  per  cent.  In  Russia,  as  well  as  in  other 
platinum-producing  regions,  chrome  iron  and  irid- 
osmium  are  associated  with  the  metal.  The  United 
States  now  consumes  more  platinum  than  any  other 
country,  incandescent  electric  lamps  and  other  elec- 
tric apparatus  calling  for  a  great  supply.  Although 
only  a  very  minute  quantity  is  required  in  each 
case,  so  many  lamps  are  called  for  that  the  demand 
is  very  great,  and  the  price  has  risen  much  higher 
than  formerly.  It  may  be  interesting  to  note  that 
the  name  platinum  is  derived  from  plata,  the  Span- 
ish word  for  silver,  since  it  was  regarded  in  South 


TELLURIUM,  PLATINUM,  SILVER.  145 

America  at  the  time  of  its  discovery  (1735)  as  an 
impure  ore  of  that  metal. 

Platinum,  like  gold,  does  not  readily  combine 
with  other  metals,  and  in  nature  the  only  com- 
pound known  is  an  arsenide  called  Sperrylite,  which 
is  found  in  very  small  quantities  in  the  Sudbury 
section  of  Ontario,  Canada.  Its  color  is  tin-white  ; 
lustre  bright ;  hardness  about  7 ;  specific  gravity 
10.6. 

Platinum  may  be  distinguished  by  its  great 
weight,  by  its  gray  color,  its  sectile  nature,  and  by 
the  fact  that  it  will  not  dissolve  in  any  simple  acid, 
and  with  difficulty  in  nitro-muriatic  acid  (aqua- 
regia).  It  may  be  distinguished  from  lead  by  its 
action  under  the  blow-pipe  flame,  since  lead  melts 
immediately,  leaving  a  yellowish  coating,  while 
platinum  refuses  to  melt  under  the  hottest  flame, 
and  leaves  no  coating  whatever.  When  it  exists  in 
the  alluvial  soil  it  may  be  "panned  out"  just  as 
gold  or  other  heavy  metals,  and  even  more  easily 
because  of  its  greater  gravity. 

It  may  be  found  in  some  metal-bearing  veins  in 
crystalline  metamorphic  and  syenite  rock,  from 
which  it  has  been  washed  down  just  as  in  the  case 
of  gold.  In  the  latter  condition  it  has  been  found 
more  extensively  than  in  any  other. 

Its  chemical  test  is  as  follows :  Dissolve  the 
grains  of  the  ore  in  nitro-muriatic  acid  (4  parts 
muriatic  acid  to  1  part  nitric),  preferably  with 
gentle  heat,  add  proto-chloride  of  tin  (solution)  also 
called  stannous  chloride  (SnCl?) ;  if  platinum  is 
10 


146 

present  a  dark  brownish-red  color  will  be  produced, 
but  no  precipitate. 

The  metal  may  be  obtained  separate  from  its  gold, 
and  in  the  presence  of  many  other  metals,  by  evap- 
orating the  above  solution  of  the  ore  in  a  porcelain 
dish  to  dryness,  at  a  gentle  heat  with  ammonium 
chloride  (sal  ammoniac  or  muriate  of  ammonia), 
and  the  residue  treated  with  dilute  alcohol  (one- 
fourth  part  water).  The  gold  will  remain  in  solu- 
tion and  the  platinum  be  precipitated,  the  precipi- 
tate to  be  ignited,  when  the  platinum  will  be  pure. 
The  gold,  if  present,  may  be  precipitated  by  adding 
a  solution  of  ferrous  sulphate,  after  evaporating  off 
the  alcohol.  Ferrous  sulphate  is  proto-sulphate  of 
iron  (copperas  in  crytals). 

Stannous  chloride  may  readily  be  purchased  at 
any  chemist's  warehouse,  but  as  it  is  easily  pre- 
pared we  give  the  best  method  as  follows:  File  a 
piece  of  tin  into  powder  aud  heat  very  hot  (nearly 
to  boiling)  with  strong  hydrochloric  acid  in  a  porce- 
lain dish  or  beaker-glass,  always  keeping  tin  in  the 
glass  or  dish,  by  adding  tin  if  necessary.  When  no 
hydrogen  gas  is  evolved  (*.  e.,  no  bubbles  arise), 
dilute  with  four  times  its  bulk  of  pure  water, 
slightly  acidulated  with  hydrochloric  (muriatic) 
acid,  and  filter.  Keep  the  filtrate  in  a  well-stop- 
pered bottle  in  which  some  tin  has  been  placed.  If 
you  have  pure  tin-foil,  that  form  of  tin  may  be  used, 
for  without  the  presence  of  metallic  tin  the  stannous 
chloride  (SnCl2)  is  in  danger  of  changing  into  stan- 
nic chloride  (SnCl4)  with  precipitation  of  a  white 


TELLURIUM,  PLATINUM,  SILVER.  147 

substance  (oxy chloride  of  tin),  which  renders  the 
reagent  unfit  for  use. 

Iridium,  a  steel-white,  extremely  hard  metal, 
next  in  specific  gravity  to  osmium,  is  supplied 
partly  from  its  alloy  with  native  platinum,  and 
partly  from  the  iridosmium  which  occurs  in  the 
platiniferous  gravels.  It  is  used  for  pen-points  and 
in  jewelry,  and  recently  in  metal-plating. 

Osmium  is  the  heaviest  known  metal.  It  comes 
from  the  same  sources  as  iridium,  and  in  the  form 
of  iridosmium  is  used  for  pointing  tools  and  pens. 

Palladium  is  a  brilliant,  silver-white  metal.  It 
also  occurs  with  platinum,  but  on  account  of  its 
high  price  is  but  little  used. 

Silver.  This  metal  occurs  native  in  various 
shapes,  as  in  small  grains  in  the  rock,  as  branching 
and  leaf-like,  and  also  in  small  octahedral  crystals 
and  in  other  forms.  Hardness,  2.3  to  3  ;  specific 
gravity,  10.1  to  11.1,  according  to  its  purity.  It  is 
never  found  absolutely  pure,  but  contains  some 
gold  and  frequently  a  little  copper. 

It  is  always  sectile  and  malleable,  and  in  this 
respect  very  easily  distinguished  from  a  substance 
frequently  mistaken  for  native  silver,  namely,  mis- 
pickel,  which  is  an  arsenide  of  iron,  having  very 
much  the  appearance  of  silver,  but  always  brittle. 

Before  the  Blow-pipe,  on  charcoal,  native  sil- 
ver is  distinguished  from  tin,  zinc,  antimony,  or 
bismuth,  by  the  fact  that  it  melts  and  leaves  no 
whiteness  or  any  other  appearance  of  oxide  upon 
the  coal  around  the  globule. 


148 

Tin  will  leave  a  white  film,  and  lead  a  yellow ; 
zinc  a  yellow  which  whitens  on  cooling.  But  silver 
leaves  no  film  or  cloud  of  any  kind  upon  the  coal. 

The  Chemical  Test  of  silver  is  as  follows :  Dis- 
solve the  metal  in  nitric  acid  in  a  test-tube,  prefer- 
ably with  the  heat  of  an  alcohol  flame,  but  not  to 
the  boiling  point.  Add  an  equal  amount  of  pure 
water  (clear  rain  water  will  answer),  then  drop  in 
several  drops  of  a  solution  of  common  table  salt  or 
muriatic  acid.  If  a  cloudy  white  precipitate  occurs 
which  settles  and  blackens  after  exposure  of  a  few 
seconds  to  sunlight  or  a  few  minutes  to  daylight, 
the  substance  is  silver. 

It  should  be  remembered  at  this  point  that  this 
test  is  for  silver  alone,  since  lead  and  mercury  are 
also  precipitated  as  a  white  cloud  by  the  same  solu- 
tion, but  neither  blackens  by  exposure  to  the  light. 
This  distinguishes  silver.  If,  however,  further 
proof  is  needed,  drop  into  the  test  tube  strong 
ammonia  water ;  the  precipitate  is  dissolved  if  it  is 
that  of  silver ;  it  is  not  if  it  be  of  lead,  and  it  is 
blackened  by  the  ammonia  if  it  is  mercury. 

If  there  is  much  copper  in  the  silver  it  may  be 
detected  by  dipping  a  clean  strip  of  polished  iron 
or  steel  into  the  solution,  for  the  metallic  copper 
will  immediately  appear  upon  the  surface  of  the 
iron. 

It  must  not  always  be  supposed  that  native  silver 
is  metallic  or  white  in  appearance,  for  it  is  readily 
tarnished  by  sulphur,  and  the  proximity  of  sulphur 
in  other  minerals  or  in  water  may  greatly  discolor 
the  native  silver. 


TELLURIUM,  PLATINUM,  SILVER.  149 

Comparatively  speaking,  very  little  of  the  silver 
of  the  mines  is  derived  from  native  silver.  Most 
of  the  silver  of  commerce  is  obtained  from  some 
of  the  minerals  named  below,  which  are  combina- 
tions of  silver  with  other  metals,  and  with  sulphur 
or  chlorine,  as  sulphides  of  silver,  etc.,  in  which 
condition  they  bear  no  resemblance  to  native  silver. 

But  in  all  silver  minerals  of  any  commercial 
value,  the  already  mentioned  tests  are  usually  suffi- 
cient to  detect  the  existence  of  silver. 

Other  forms  in  which  silver  is  found  are — 

Silver  Sulphides  are  very  largely  associated 
with  lead  sulphides  or  galena,  and  sometimes  called, 
when  pure, 

Silver  Glance  or  Argentite.  This  is  found  in 
masses,  but  when  crystallized  it  occurs  in  cubes  or 
octahedral  forms.  When  freshly  broken  it  has 
a  metallic  lustre,  otherwise  it  is  of  a  dull  gray  or 
leaden  appearance.  It  is  sectile,  and  its  "  streak  " 
or  the  color  of  its  powder  is  the  same  as  that  of  the 
mineral  itself,  and  rather  shining.  Chemical  com- 
position :  silver  87 ;  sulphur  13.  Hardness  2  to 
2.5.     Specific  gravity  7.1  to  7.4. 

The  ore  is  soluble  in  nitric  acid,  and  on  adding 
common  salt  to  the  solution,  a  white  curd  is  thrown 
down  which  blackens  on  exposure  to  sunlight.  It 
is  very  fusible,  giving  off  an  odor  of  sulphur  when 
heated.  Before  the  blow-pipe  on  charcoal,  with  or 
without  carbonate  of  soda,  it  yields  a  white  globule 
of  metallic  silver  which  can  be  flattened  under  a 
hammer. 


150      prospector's  field-book  and  guide. 

The  ore  in  an  amorphous  state  is  most  common 
in  earthy  vein-stuff  (called  metal  azul)  or  with 
pyritic  minerals,  especially  galena.  It  is  rarely 
recognizable  by  form  or  physical  character,  as  rich 
quartz  only  differs  from  ordinary  by  its  pale  bluish- 
gray  tint,  and  argentiferous  galena  is,  as  a  rule, 
undistinguishable  by  sight  from  that  containing  no 
silver. 

Ceragyrite  or  horn  silver.  The  mineral 
known  under  this  name  is  a  chloride  of  silver  oc- 
curring in  veins  of  clay  slate  with  other  ores  of 
silver,  usually  only  in  the  higher  parts  of  these 
veins.  With  ochreous  brown  iron  ore  with  several 
copper  ores,  etc.  Lustre,  waxy,  resinous.  It  yields 
a  shining  streak.  It  is  translucent  on  the  extreme 
edges  and  has  a  waxy  appearance.  It  cuts  like 
horn  or  wax,  and  on  an  outcrop  looks  like  dirty 
cement.  It  contains  75.3  per  cent,  silver,  and  24.7 
per  cent,  chlorine  when  unmixed  or  nearly  pure, 
and  then  has  a  pearly-gray  or  greenish-gray  appear- 
ance. 

A  polished  piece  of  iron  may  be  slightly  coated 
with  silver  if  a  piece  of  horn  silver  is  moistened  and 
rubbed  upon  the  iron. 

Horn  silver  is  very  easily  fusible,  it  melting  in 
the  flame  of  a  candle.  Heated  with  carbonate 
of  soda  on  charcoal,  it  yields  a  globule  of  metallic 
silver. 

This  mineral,  in  various  degrees  of  impurity, 
forms  a  very  large  part  of  the  silver-bearing  ores 
of  some  mines  in  South  America,  as  well  as  in  the 


TELLURIUM,  PLATINUM,  SILVER.  151 

Western  States  and  Territories  of  the  United  States. 
It  is  a  valuable  ore. 

Stephanite  or  Brittle  Silver  Ore  is  a  silver 
sulphide  with  antimony,  and  is  found  in  masses  and 
sometimes  in  rhombic  prism  crystals  in  veins  with 
other  silver  ores.  It  is  easily  distinguished  from 
silver  sulphide  (or  glance)  by  the  fact  that  it  is 
brittle,  while  the  glance,  if  fairly  pure,  may  be  cut 
with  a  knife  in  chips  without  breaking. 

This  ore  is  black  or  iron  gray,  has  a  hardness  of  2 
to  2.5  and  a  specific  gravity  of  6.2  to  6.3,  and  when 
pure,  contains  71  per  cent,  of  silver,  the  rest  being 
antimony  with  some  other  admixtures,  usually  iron 
or  copper.  It  is  an  abundant  silver  ore  in  the 
Comstook  Lode,  Nevada  (Figs.  47,  48),  in  the  Reese 
River  and  Humboldt  and  other  regions,  and  at  the 
silver  mines  in  Idaho. 

On  charcoal,  under  the  blow-pipe,  it  decrepitates 
and  coats  the  coal  with  a  film  of  antimony  (anti- 
monous  acid),  which,  after  considerable  blowing, 
turns  red,  and  a  globule  of  silver  is  obtained. 

Red  Silver  Ore,  or  Ruby  Silver,  is  an  ore 
which  contains  arsenic  and  antimony,  or  more  usu- 
ally arsenic  or  antimony.  That  containing  only 
antimony  is  dark  red  and  is  known  mineralog- 
ically  as  Pyrargyrite  ;  it  contains  59.8  per  cent, 
silver,  17.7  per  cent,  sulphur,  and  22.5  per  cent,  of 
antimony.  It  occurs  generally  in  crystals.  When 
the  silver  sulphide  is  associated  with  arsenic  only, 
the  color  is  light  red  and  the  name  Proustite  is 
applied  to  it.     It  contains  65.5  per  cent,  of  silver. 


152      prospector's  field-book  and  guide. 

It  may  contain  both  arsenic  and  antimony,  and 
have  a  grayish  appearance.  In  Idaho,  it  has  been 
found  in  masses  of  several  hundred  pounds  weight, 
at  Poorman  Lode  (Dana).  In  Mexico  it  is  worked 
extensively  as  an  ore  of  silver. 

Bromic  Silver  or  Bromyrite.  This  is  a  com- 
mon ore  containing  bromine  42.6  per  cent,  and 
silver  57.4  per  cent. 

There  are  other  minerals  in  which  silver  occurs, 
but  they  are  only  exceptions  or  rare,  and  if  one  is 
acquainted  with  those  mentioned  above,  he  will 
very  likely  detect  the  rarer  silver  minerals,  which 
are  not  ores  in  the  usual  sense,  but  they  may  lead 
when  discovered  to  valuable  results. 

Valuing  silver  ores.  A  simple,  but  rough,  method 
is  sometimes  adopted  of  testing  the  value  of  ores 
from  day  to  day  when  chlorides  are  the  minerals 
chiefly  worked,  by  powdering  the  ore  in  the  mine, 
mixing  it  with  a  solution  of  hyposulphite  of  lime 
which  dissolves  the  chloride,  and  then  adding 
sodium  sulphide,  which  forms  a  dark-colored  pre- 
cipitate if  much  silver  is  present.  It  is  evidently 
impossible  to  estimate  in  this  way  the  contents  of 
silver,  but  it  affords  a  very  good  test  whether  the 
ore  is  of  value  or  not. 

Geology  of  Silver  Ores.  The  most  valuable 
ores  occur  in  the  earlier  or  more  ancient  rocks,  such 
as  the  granitic  or  gneissoid  rocks,  clay  slates,  mica 
schists,  older  limestones,  and  in  the  metamorphic 
rocks.  The  remarkable  geologic  conditions  under 
which  silver  ores  and  veins  occur  may  be  under- 


TELLURIUM,  PLATINUM,  SILVER.  153 

stood  more  readily  by  the  following  diagrams  than 
by  any  descriptions  without  them.  (Figs.  47  and 
48.) 

In  the  diagrams  the  rocks  are  seen  tilted  up  from 
the  horizontal  position  to  one  nearly  vertical,  but 
evidently  after  this  uplifting  the  trachytic  dykes 
were  shot  through  the  masses  of  conglomerate. 
The  lodes  bearing  silver  are  represented  by  contin- 
uous double  lines,  and  the  dykes  by  dotted  vertical 
lines.  The  entire  distance  represented  from  Sutro 
to  the  west  end  of  the  diagram  is  about  5J  miles, 
on  a  course  east  and  west,  being  the  same  as  that  of 
the  Sutro  tunnel  upon  this  branch,  which  joins  or 
intersects  to  the  north  and  south  branch  of  the 
tunnel  at  the  Comstock  lode. 

In  order  that  the  superficial  nature  of  the  country 
may  be  understood,  we  have  given  the  north  and 
south  section  of  the  same  region,  showing  some  of 
the  mines  by  vertical  black  lines  and  by  shaded 
spaces  where  the  mines  have  been  worked  more  or 
less  extensively.     (Fig.  48.) 

The  north  and  south  section  exhibits  the  hilly 
surface,  and  fully  illustrates  the  work  of  the  pros- 
pector who  would  become  acquainted  with  the  min- 
eral deposits  of  a  similar  region. 

It  will  be  seen  in  the  east  and  west  section  that 
all  the  lodes  out-crop.  (Fig.  47.)  The  non-metallic 
substances  of  these  lodes  are  quartz,  fluorspar,  with, 
perhaps,  some  chlorides  or  sulphides  ;  the  latter  may 
be  metallic,  and  there  may  occur  some  traces  of 
gold  and  silver,  perhaps  also  of  antimony,  lead,  etc. 


154 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


o  -e 


TELLURIUM,  PLATINUM,  SILVER.  155 

The  wisest  course,  therefore,  is  for  the  prospector, 
after  having  settled  in  which  direction  the  strike  or 
course  of  the  strata  runs,  to  make  an  examination 
directly  across  the  strata,  the  chief  object  being  to 
learn  the  nature  of  the  rocks  of  the  region,  and,  at 
the  same  time,  to  detect  the  outcropping  of  any 
lodes  or  dykes. 

His  object  is  to  become  acquainted  with  the  strata 
by  means  of  the  loose  material,  the  fragments,  or 
small  outcropping  rocks,  where  he  cannot  penetrate 
beneath  the  soil. 

It  may  become  necessary  to  traverse  a  great  dis- 
tance before  any  certain  information  may  be  gained, 
and  where  the  hill  surfaces  are  covered  with  soil,  the 
ravines  will  frequently  disclose  the  nature  of  the  rock. 

It  will  be  noticed  that  the  Comstock  Lode  begins 
immediately  adjoining  the  syenite  rock,  and  at  the 
outcrop  extends  six  or  eight  times  the  actual  thick- 
ness of  the  lode  below.  It  is  also  apparent  that  the 
lodes  generally,  at  least  in  this  region,  bifurcate 
near  the  surface,  even  in  the  syenite,  and  when  an 
outcrop  has  been  discovered,  the  probability  is  that 
not  far  off  another  outcrop  of  the  same  lode  may  be 
found  (Fig.  47). 

The  Comstock  Lode  has  been  traced  for  four  or 
five  miles  north  and  south,  but  the  values  of  the 
deposits  are  not  uniform.  The  great  bodies  of  ore 
may  be  seen  in  the  north  and  south  section  where 
the  excavations  are  largest,  as  around  the  Savage, 
and  from  the  Exchequer  to  the  Crown  Point  prop- 
erties.    But  this  whole  region  is  filled  with  dykes 


156      prospector's  field-book  and  guide. 


TELLURIUM,  PLATINUM,  SILVER.  157 

and  lodes  for  miles  beyond  the  Comstock  Lode, 
which  lies  on  the  eastern  slope  of  a  range  of  hills 
running  somewhat  parallel,  but  about  fifteen  miles 
east  of  the  great  Sierra  Nevada  range,  south  of  the 
Pacific  Railroad,  and  between  the  lakes  Bigler  and 
Carson  in  the  western  part  of  the  State. 

In  the  east  of  Nevada,  at  the  Eureka  Mines,  the 
ores  are  found  in  a  bed  of  limestone  overlying  the 
granites,  quartzose  slates,  and  metamorphic  rocks 
of  great  thickness.  The  limestone  containing  the 
ore  is  about  300  feet  thick.  But  while  the  imme- 
diate geology  varies  from  that  of  the  Comstock,  the 
general  facts  are  the  same,  namely,  that  the  silver- 
bearing  lodes  are  in  or  very  near  the  granites  or 
earliest  rocks.  In  this  case  the  overlying  rocks, 
though  limestone,  are  dolomitic,  containing  from 
36  to  46  per  cent,  of  carbonate  of  magnesia,  and  the 
mineralized  belt  of  limestone,  or  that  containing 
the  ores,  is  very  much  broken,  and  in  some  places 
apparently  crushed,  as  if  it  had  been  subjected  to  a 
grinding  process,  and  then  partly  rejoined  by  the 
cementing  power  of  calcareous  matter  deposited 
from  solution  in  percolating  water. 

A  peculiarity  in  this  last  described  limestone  is 
found  in  the  large  caverns  which  occur  along  the 
course  of  mineral  deposit.  On  the  floors  of  these 
caverns  are  found  beds  of  ore  which  seem  to  have 
dropped  from  their  position  in  the  limestone,  as 
that  has  been  dissolved  out  and  carried  off  where 
the  fissures  easily  permitted  the  percolating  waters 
to~pass  rapidly  away. 


158      prospector's  field-book  and  guide. 

The  geology  of  this  region  appears  to  be  in  the 
order  of  granites,  quartzose  slates  and  metamorphic 
rocks  of  great  thickness,  limestones  containing 
segregations  of  ore,  calcareous  shales,  and  these 
surmounted  by  limestones  also  of  great  thickness. 
The  special  region  to  which  this  geological  series 
refers  is  the  Ruby  Hill  mines. 

The  Emma  Mine,  with  many  others,  is  situated 
still  further  east,  in  the  Wahsatch  range  of  moun- 
tains, which  runs  north  and  south  about  twenty 
miles  east  of  the  Great  Salt  Lake.  This  mine  is 
about  the  same  distance  southeast  of  the  Great  Salt 
Lake.  The  adjacent  rocks  of  this  mine  are  granite, 
in  massive  beds,  dipping  from  50°  to  70°  eastward. 
This  is  overlaid  by  quartzites  of  a  reddish  color, 
then  occurs  a  series  of  slates,  upon  which  are  thick 
beds  of  white  limestone,  and  these  pass  rapidly  into 
the  carboniferous  dolomitic  limestone.  It  is  in  this 
last  limestone  that  the  ore  deposits  of  the  Emma 
and  adjacent  mines  are  worked. 

It  is  a  fact,  however,  that  the  ores  are  mainly 
composed  of  silica  and  lead,  of  which  there  is  over 
70  per  cent.  The  amount  of  silver  is  about  0.40  to 
0.50  of  1  per  cent,  according  to  some  analyses.  A 
sample  amount  of  82  tons,  gross,  yielded  156  ounces 
of  silver. 

These  three  mining  districts  present  the  general 
geologic  conditions  in  which  the  silver  ores  are 
found  in  these  and  other  States  and  Territories,  and 
the  prospector  should  expect  to  find  surface  indica- 
tions accordingly,  but  modified  more  or  less  by  ex- 
posure to  weather. 


TELLURIUM,  PLATINUM,  SILVER.  159 

Although,  from  the  preceding  illustrations,  silver 
is  shown  to  be  found  both  in  the  very  early  groups 
of  rocks  and  in  the  carboniferous  limestone,  the 
latter  is  the  exception,  as  it  appears  to  be  found 
there  only  when  that  limestone  has  occurred  with 
little  or  no  separating  horizons  from  the  earliest 
rocks. 


CHAPTER  VIII. 
Copper. 

Copper  occurs  both  native  and  in  a  compound 
state.  Native  copper  is  found  in  various  forms, 
and  even  in  octahedral  crystals.  Its  color  is  copper 
red ;  it  is  always  sectile  and  malleable ;  hardness 
2.5  to  3,  specific  gravity  8.5  to  8.9,  according  to 
purity.  Frequently  associated  with  native  silver. 
It  is  tested  by  the  blow-pipe ;  giving  in  small  quan- 
tities a  blue  tinge  to  almost  black  in  the  borax  bead, 
according  to  quantity  used,  and  the  kind  of  flame, 
whether  inner  or  R,  or  outer  or  0,  the  latter  giving 
blue  color,  the  former  giving  the  copper  color  or 
metallic  opaque  brown. 

Native  copper  dissolves  readily  in  nitric  acid, 
and  if  ammonia  be  added,  the  solution  becomes 
green,  or  greenish-blue  if  ammonia  be  in  excess. 

In  the  absence  of  any  chemicals  or  a  blow-pipe, 
the  mineral,  when  containing  native  copper,  or 
when  only  a  compound  containing  copper,  may  be 
tested  by  heating  it  either  in  the  mass,  or,  better,  in 
powder,  and  when  hot,  dropping  it  into  some  salty 
grease  and  then  putting  it  in  a  flame  or  upon  burn- 
ing charcoal,  when  the  characteristic  green  color 
will  appear  in  the  flame  with  great  distinctness. 
(160) 


COPPER.  161 

Moreover,  if  the  mineral  contains  copper  in  con- 
siderable quantity  and  it  is  dissolved  in  nitric  acid, 
the  copper  will  be  deposited  immediately  upon  a 
strip  of  polished  iron  or  upon  the  end  of  a  knife 
blade,  if  either  be  dipped  into  the  solution. 

The  natural  combinations  of  copper  are  almost 
endless.  Not  less  than  a  hundred  mineral  species 
may  be  regarded  as  copper  ores  from  the  practical 
miner's  point  of  view,  i.  e.,  possessing  economic 
value,  and  there  are  probably  as  many  more  which 
are  not  yet  utilized.  As  might  be  expected  the 
range  of  chemical  associations  is  equally  wide,  em- 
bracing sulphides,  antimonides,  arsenides,  oxides, 
chlorides,  bromides,  iodides,  carbonates,  sulphates, 
phosphates,  silicates,  arseniates,  simple  and  com- 
pound, hydrated  and  anhydrous,  in  almost  every 
degree  of  variety. 

Below  several  of  the  more  important  ores  of 
copper  are  mentioned,  and  also  some  copper  min- 
erals which,  to  the  prospector,  will  be  suggestive 
that  the  more  important  ores  are  not  far  off. 

Cuprite,  Red  Copper  Ore  or  Ruby  Copper. 
Occurs  massive,  granular,  and  earthy.  Streak, 
shades  of  brownish-red,  shining.  Brittle.  Color, 
deep  crimson,  cherry-red  ;  opaque  with  very  bril- 
liant reflection ;  sometimes  weathered  to  an  iron- 
gray  on  the  surface.  Hardness,  3.5  to  4  ;  specific 
gravity,  8.  Composed  of  copper,  88.78  per  cent., 
the  remainder  oxygen,  when  pure. 

Before  the  blow-pipe,  on  charcoal,  it  yields  a 
globule  of  metallic  copper ;  with  borax  bead  gives 
11 


162 

the  indication  of  copper.  Dissolves  in  hydrochloric 
acid,  giving  a  brown  solution  which,  when  diluted 
with  water,  deposits  white  insoluble  cupric  chloride. 
In  nitric  acid  it  forms  a  blue  solution.  Sulphuric 
acid  decomposes  it  into  cupric  oxide  (CuO)  and 
metallic  copper,  the  former  passing  into  solution  as 
cupric  sulphate,  while  the  latter  is  undissolved. 

Cuprite  occurs  in  granite  and  slate  with  copper 
ores  and  galena  and  forms  a  valuable  source  of  the 
metal.  The  massive  variety  is  known  as  tile  ore ; 
brick  ore  is  a  mixture  of  copper  and  limonite.  The 
fibrous  variety  is  known  as  plush  copper  ore. 

Chalcocite,  Copper  Glance  or  Vitreous  Cop- 
per. Massive ;  slightly  sectile.  Color  and  streak, 
bluish-lead  gray,  brownish ;  brilliant  when  fresh ; 
black  and  dull,  on  exposure  to  sunlight  tarnishing 
to  blue  or  iridescent.  Hardness  2.5-3 ;  specific 
gravity  5.5-5.8.  Composed  of  copper  77.2;  sul- 
phur 20.6,  and  sometimes,  a  little  iron.  It  is 
fusible  in  a  candle  flame. 

Before  the  blow-pipe  it  gives  off  an  odor  of  sul- 
phur. When  heated  on  charcoal,  a  malleable 
globule  of  metallic  copper  remains,  tarnished  black, 
but  rendered  evident  on  flattening  under  a  hammer. 
With  borax  bead  it  gives  the  indications  of  copper. 
Dissolves  in  nitric  acid,  forming  a  blue  solution. 
These  tests  distinguish  it  from  sulphide  of  silver. 
Occurs  with  other  copper-ores. 

Tetrahedrite  or  Gray  Copper  Ore.  Brittle  ; 
steel-gray  or  iron-black,  sometimes  brownish  ;  hard- 
ness 3-4 ;  specific  gravity  4.75-5.1.     Composed  of 


COPPER.  163 

copper  38.6,  sulphur  26.3,  and  frequently  antimony 
and  arsenic,  zinc,  iron,  silver,  etc.  It  frequently 
contains  silver,  and  sometimes  as  much  as  25  to  30 
per  cent. 

Before  the  blow-pipe  on  charcoal  it  fuses,  gives 
an  incrustation  of  antimonious  and  sometimes 
arsenious  acid,  oxide  of  zinc  and  oxide  of  lead. 
Arsenic  may  be  detected  by  its  odor  on  heating 
incrustation  in  R.  F.  or  fusing  with  soda.  Oxide 
of  zinc  gives  a  green  color  when  heated  with  nitrate 
of  cobalt  solution.  The  iron  and  copper  in  the  resi- 
due are  found  either  by  fluxes  (on  platinum)  or  by 
reduction  with  soda.  Silver  is  determined  by  cupel- 
lation. 

Tetrahedrite  is  soluble  in  nitric  acid,  arsenious 
and  antimonious  acids  separating.  The  solution 
becomes  blue  from  copper  by  adding  ammonia  in 
excess,  and  cloudy  with  hydrochloric  acid  when 
silver  is  present. 

Tetrahedrite  occurs  with  copper  pyrites,  galena 
and  blende.  It  is  worked  for  copper  and  occasion- 
ally for  silver. 

Chalcopyrite  or  Copper  Pyrites.  Massive. 
Color,  brass-yellow,  when  fresh,  gold-yellow  when 
tarnished.  Lustre,  sub-metallic ;  brittle,  slightly 
sectile.  Hardness,  3.5  to  4 ;  specific  gravity,  4.15. 
Composed  of  copper  34.6,  sulphur  34.9,  iron  30.5. 
Before  the  blow-pipe  it  fuses  with  intumescence  and 
scintillation  to  a  rough  magnetic  globule.  When 
powdered  and  roasted  at  a  low  heat,  it  is  converted 
into  a  fritted  mass,  giving  reactions  of  copper  and 


164 

iron  with  fluxes.  With  soda  on  charcoal,  gives  a 
globule  of  metallic  iron  and  copper.  It  is  sometimes 
mistaken  for  gold,  or  iron,  or  tin  pyrites.  But  it  is 
brittle,  while  gold  is  not ;  it  will  not  strike  fire  as 
does  iron  pyrites  ;  and  it  may  be  distinguished  from 
tin  pyrites  by  the  film  that  the  latter  leaves  on  the 
charcoal,  while  copper  pyrites  leaves  no  residue 
under  the  blow-pipe.  It  occurs  in  granite  and  slate 
in  lodes  or  veins,  and  is  a  valuable  ore  of  copper. 

What  is  called  peacock  ore  is  only  pyrites  coated 
with  oxide  and  exhibiting  iridescent  colors.  By 
leaving  a  piece  of  clean  yellow  copper  pyrites  in 
water  for  some  time  it  will  become  coated  in  this 
way. 

Chrysocolla  or  Silicate  of  Copper.  Accom- 
panies other  copper  ores,  occurring  especially  in  the 
upper  part  of  veins.  It  is  a  bright  green  or  bluish 
green  mineral,  scarcely  worthy  of  being  called  an 
ore,  although  it  contains  from  35  to  40  per  cent, 
copper  and  a  large  amount  of  silica.  It  is  a  second- 
ary deposit.  Its  hardness  is  2  to  4,  and  specific 
gravity  2  to  2.3.  Its  only  significance  to  the  pros- 
pector is  that  it  may  be  associated  with  true  ores. 
Its  powder  (streak)  is  white,  while  the  mineral  itself 
is  green  ;  this  being  due  to  the  quartz  or  silex  in  it. 
It  does  not  entirely  dissolve  in  nitric  acid.  Before 
the  blow-pipe  with  soda,  it  gives  a  bead  of  copper. 

Black  Oxide  of  Copper  is  usually  found  on  the 
surface.  Soils  the  fingers  when  pulverulent.  It  is 
a  result  of  decomposition  of  copper  ores,  as  a  deposit 
on  surface  of  copper  pyrites.     It  occurs  in  masses 


COPPER.  165 

of  a  dark,  earthy  appearance,  sometimes  in  minute 
shining  particles. 

Malachite  or  Green  Carbonate  of  Copper, 
has  a  fibrous  structure  nearly  opaque,  and  of  an 
emerald-green  color,  and  contains  about  57  per 
cent,  of  copper.  Hardness  3.5  to  4  ;  specific  gravity 
3.6  to  4.  Commonly  found  near  the  surface  of  veins 
containing  copper  ores. 

Before  the  blow-pipe  it  becomes  blackish.  With 
borax  it  yields  the  usual  blue-green  bead,  and  on 
charcoal  is  reduced  to  metallic  copper.  It  com- 
pletely dissolves  in  nitric  acid,  and  thus  it  may  be 
distinguished  from  silicate  of  copper,  which  has 
nearly  the  same  color  and  will  not  dissolve. 

Azurite  or  Blue  Carbonate  of  Copper  is 
chiefly  used  for  ornamental  purposes.  It  is  of  a 
deep  cobalt  blue  color  sometimes  transparent,  brittle, 
and  gives  a  bluish  streak.  It  has  a  hardness  of  3.5 
to  4.5  and  a  specific  gravity  of  3.7  to  4.  Can  be 
scratched  with  a  knife.  It  blackens  when  heated. 
On  charcoal  it  is  reduced  to  a  globule  of  pure  cop- 
per. With  the  borax  bead  it  gives  the  indications 
of  copper.  It  is  soluble  in  nitric  acid  with  effer- 
vescence, forming  a  blue  solution. 

Variegated  Copper  Pyrites  (Bomite  is  the 
mineralogical  name,  but  is  also  called  Erubiscite) : 
Usually  massive,  of  a  copper-red  to  a  pinchbeck- 
brown  color,  and  a  blackish  to  lead-gray  streak. 
Hardness  2.5  to  3,  specific  gravity  5.5  to  5.8.  It 
contains  79.8  per  cent,  copper  and  20.2  per  cent,  of 
sulphur.  Before  the  blow-pipe  it  gives  a  bead  of 
copper. 


166      prospector's  field-book  and  guide. 

But  the  minerals  above  mentioned  are  by  no 
means  the  most  important  as  regards  the  commer- 
cial supplies  of  the  metal ;  in  fact,  in  that  light  they 
may  almost  be  disregarded  so  far  as  affording  any 
considerable  proportion  of  the  total  yearly  output, 
though,  of  course,  deposits  of  these  ores  are  profit- 
able. The  bulk  of  the  world's  consumption  of  cop- 
per is  furnished  by  ores  of  the  lowest  grade,  ranging 
from  little  more  than  J  to  perhaps  5  per  cent., 
though  rarely  more  than  3  to  3J  per  cent.  Thus 
the  ores  of  Devon  and  Cornwall  are  worked  for  1J 
to  2  per  cent,  copper ;  those  of  Cheshire,  for  less  than 
1J  per  cent.;  those  of  Mausfield,  Germany,  for  little 
over  2  J  per  cent.;  those  of  Eio  Tinto,  Spain,  for  2 J 
to  3 J  per  cent.;  those  of  Maidenpec,  Servia,  for  2  to 
3  per  cent.;  and,  overwhelmingly  the  most  abund- 
ant producers,  those  of  the  Lake  Superior  region  for 
as  little  as  0.65  per  cent. 

Formerly  the  world's  supply  of  copper  was  drawn 
from  the  rich  ores,  containing  up  to  40  per  cent,  of 
metal  as  mined,  and  further  explorations  may  again 
reveal  in  the  future  similar  deposits  to  replace  those 
now  exhausted  ;  but  at  present  and  in  the  immedi- 
ate future  reliance  must  be  placed  on  the  enormous 
low  grade  ore  bodies  now  being  worked,  especially 
in  North  America. 

The  geology  of  copper  is  more  varied  than  that 
of  many  other  metals,  as  it  occurs  in  rocks  of  almost 
every  age.  In  Cornwall  the  slates  are  more  pro- 
ductive than  the  granites,  while  in  our  mines  in  the 
Eastern  States  the  new  red  sandstone,  the  carbon- 


COPPER. 


167 


iferous  limestone,  and  silurian  rocks  furnish  copper. 
Also  found  in  the  metamorphic  limestone,  near 
slate  (Fig.  49).  In  the  Lake  Superior  region,  where 
large  deposits  of  native  copper  are  found,  the  rocks 
are  sandstones  and  shales  underlying  green-stone  or 
a  kind  of  trap,  and  in  some  places  seem  to  be  igne- 
ous (Figs.  50,  51).  Ruby  copper  ore  occurs  in  Ari- 
zona between  quartzose  and  hornblendic  rocks  and 


Section  of  the  copper  bed  at  the  Dolly  Hide  mine,  Maryland,  a, 
Slate,  b,  b,  b,  b,  Ore  beds  or  segregations  of  ore.  c,  c,  c,  c,  Crystalline  lime- 
stone (metamorphic). 

limestone.  It  occurs  in  both,  lodes  and  deposits, 
and  the  best  way  for  the  prospector  to  prepare  for 
actual  discovery  is  to  make  himself  well  acquainted 
with  the  copper  compounds,  whether  ores  or  min- 
erals. They  may  indicate  true  ores,  although  they 
contain  little  copper. 

To  become  ready  in  the  detection  of  copper  as  an 
ore  the  following  facts  should  be  kept  in  mind,  as 


168 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


furnishing  suggestions  for  skillful  practice.     (Figs. 
49,  50,  and  51.) 

It  is  well  to  remember,  especially  when  exploring 
a  new  country,  that  copper  is  frequently  associated 
with  rocks  of  a  dark  color,  which  are  very  often 

Fig.  50. 


«•     _K>     c 


Section  op  strata  in  Lake  Superior  copper  region  :  a,  Granite,  b,  Gneis- 
soid.  c,  Greenstone,  hornblende,  conglomerates  with  interstratified  slates. 
d,  Slaty  rocks  and  traps,  etc.  e,  Potsdam  sandstone.  C,  C,  Places  of  copper 
deposits.    0,  B,  Iron  ore  beds.    Section  from  N.  W.  to  S.  E. 

green  ;  but  it  must  not  be  supposed  that  the  color 
is  imparted  by  copper,  for  it  is  generally  due  either 
to  some  other  metal,  such  as  iron,  or  to  the  presence 
of  a  green  non-metallic  mineral,  such  as  chlorite. 
Serpentines  and  hornblendic  rocks  are  often  associ- 


Fig.  51. 


Copper.  Section  of  the  Eagle  vein,  Lake  Superior,  a,  Poryphyritic 
rocks.  6,  Greenstone,  c,  c,  Conglomerate,  d,  d,  d,  Amygdaloid  bearing 
copper,    e,  e,  e,  Shafts.   /,  Montreal  River. 

ated  with  copper  ores,  but  green  serpentines  owe 
their  color  to  iron,  nickel  or  chromium,  and  if  cop- 
per is  found  disseminated  through  some  of  them,  it 
is  the  exception  and  not  the  rule,  unless  in  the 


COPPER.  169 

immediate  vicinity  of  ore  deposits.  On  the  con- 
trary, iron  and  chromium  are  found  in  all  serpen- 
tines, and  nickel  is  of  frequent  occurrence. 

All  copper  ores  weigh  more  than  quartz  or  lime- 
stone, and  the  comparative  weights  should  be  so 
well  known  by  practice  that  there  should  be  no 
hesitation  in  judging  that  the  mineral  you  hold  is 
more  than  2.6  in  specific  gravity,  2.6  being  that  of 
either  quartz  or  limestone. 

Next  examine  the  mineral  with  your  pocket  lens 
for  any  evidence  of  copper,  such  as  green  or  bluish 
spots,  or  brassy  points  or  particles ;  if  found,  chip 
one  off  and  use  the  blow-pipe  with  borax  bead  or 
with  soda  or  borax  on  charcoal.  If  the  character- 
istic color  appears,  it  is  copper.  Now  proceed  with 
other  parts  of  the  specimen.  If  a  sulphury  smell  is 
plain,  it  is  probably  a  sulphide.  Place  a  small  chip 
upon  a  depression  in  the  charcoal,  cover  with  soda 
or  borax,  turn  the  inner  flame  upon  it  and  reduce 
to  a  metallic  globule  ;  if  it  shows  the  color  of  copper 
and  is  malleable,  it  is  copper  ;  if  it  blackens,  apply 
your  magnetized  knife-blade,  and  if  it  is  attracted, 
the  mineral  contains  iron,  and  it  may  contain  both 
iron  and  copper. 

The  next  work  is  to  examine  the  region  to  gather 
any  other  specimens  and  evidences  of  true  ores, 
before  attempting  to  know  more  of  any  particular 
specimen.  If  the  surface  specimens  are  numerous 
it  may  be  well  to  gather  some  six  or  eight  and  pro- 
ceed to  an  examination  as  to  the  available  copper. 
This  is  now  the  work  of  the  chemist,  and  should  be 


170 

submitted  to  him.  But  as  the  skillful  prospector 
frequently  wishes  to  be  his  own  chemist,  where 
work  for  the  desired  object  is  not  difficult  nor  very 
complicated,  we  give  the  following  simple  process  of 
arriving  at  the  per  cent,  of  copper  in  an  ore  without 
regard  to  other  elements  contained  therein : 

To  OBTAIN  THE  PER  CENT.  OF  COPPER  IN  AN  ORE. 

The  only  chemicals  needed  are  nitric  acid,  ammonia, 
and  sodium  sulphide — the  colorless  crystallized  hy- 
drosulphide  of  soda  of  commerce  is  good  enough. 
All  the  apparatus  needed  is  a  glass  flask  or  tall 
beaker-glass  and  a  marked  tall  glass  called  a  burette. 
This  glass  may  be  obtained  at  any  chemical  ware- 
house. The  burette  is  marked  in  cubic  inches  or 
cubic  centimetres,  from  25  to  100.  Dissolve  some 
sodium  sulphide  in  clear  rain-water — about  a  half 
ounce  to  a  pint.  Keep  the  solution  in  a  glass- 
stoppered  bottle.  Obtain  some  pure  copper  (ordi- 
nary good  copper  wire  will  answer),  weigh  the  piece 
accurately  and  dissolve  in  nitric  acid,  add  some 
water  (twice  the  amount  of  acid  used,  or  a  little 
more),  then  add  ammonia  until,  when  stirred  with 
a  long  piece  of  glass  or  glass  rod,  the  solution  smells 
strongly  of  ammonia.  The  ammonia  must  be  in  ex- 
cess. Now  fill  the  burette  with  sodium  sulphide  to 
the  100  mark,  and  from  the  burette  pour  into  the 
copper  solution  until  the  blue  color  of  copper  en- 
tirely disappears ;  note  on  the  burette  by  its  marks 
the  exact  amount  of  sodium  sulphide  used.  That 
amount  represents  the  weight  of  the  amount  of  cop- 
per used. 


COPPER.  171 

Now  for  the  ore  :  Pulverize  some  of  the  averaged 
ore,  weigh  it,  and  treat  it  as  you  did  the  copper, 
with  nitric  acid  and  ammonia,  and  proceed  with 
the  sodium  sulphide.  When  the  ore  solution  has 
become  entirely  colorless,  note  what  amount  of 
sodium  sulphide  solution  you  have  used,  and  you 
may  then  calculate  the  exact  amount  of  copper  in 
the  ore  by  simple  proportion.  The  presence  of  tin, 
zinc,  lead,  iron,  cadmium,  antimony,  arsenic,  or 
bismuth  in  the  ore  does  not  interfere  with  the  oper- 
ation. But  silver  does.  Therefore,  a  small  amount 
of  the  ore  must  be  dissolved  in  nitric  acid  (free  from 
all  muriatic  acid  or  chlorine,  as  this  would  precipi- 
tate the  silver  before  you  would  notice  it),  and 
tested  by  dropping  into  the  solution  a  drop  or  two 
of  hydrochloric  acid  or  solution  of  common  table 
salt  (sodium  chloride).  If  any  silver  exists  in  the 
ore  a  milky  cloudiness  will  appear,  of  a  density 
greater  or  less  in  accordance  with  the  amount  of 
silver  present.  If  no  silver  appears,  then  you  may 
proceed  as  already  directed.  If  silver  does  appear, 
then  the  solution  containing  the  weighed  ore  must 
first  be  treated  with  the  salt  solution  or  diluted 
hydrochloric  acid,  until  all  cloudiness  or  white  pre- 
cipitate entirely  ceases.  The  solution  of  ore  now 
contains  no  silver,  and  you  may  proceed  as  directed. 

This  process  is  sufficiently  accurate  for  all  assays, 
provided  the  following  precautions  are  observed  : — 

1.  Heat  the  copper  solution,  after  adding  the  am- 
monia, to  boiling  point  or  little  below  while  adding 
the  sodium  sulphide.     2.  Add  a  little  ammonia  to 


172 

the  ammoniacal  solution  to  keep  it  from  losing 
ammonia  by  evaporation.  3.  When  the  blue  am- 
moniacal solution  begins  to  lose  its  color,  drop  the 
sodium  sulphide  in  cautiously,  so  as  not  to  exceed 
the  amount  necessary  to  exactly  precipitate  the 
copper  and  no  more. 

Note  the  precipitates :  The  sodium  sulphite  first 
produces  its  black  precipitate  of  copper  sulphide, 
but  before  that  takes  place  the  ammonia  will  pro- 
duce another  precipitate,  provided  the  copper  con- 
tains any  lead  or  tin.  If  the  copper  contains  zinc, 
that  will  be  precipitated  immediately  following  the 
black  copper  sulphide,  but  will  be  white.  If  it  con- 
tains any  cadmium,  that  will  be  precipitated  at  the 
very  moment  the  decoloration  takes  place,  if  the 
adding  of  the  sodium  sulphide  is  continued.  Cad- 
mium is  known  by  a  beautiful  clear  yellow  precipi- 
tate.    With  care  and  skill  each  may  be  noticed. 

In  simply  determining  the  amount  of  copper, 
however,  no  regard  need  be  had  to  any  of  these 
precipitates,  only  pay  attention  to  the  point  of  de- 
coloration. 

The  sodium  sulphide  may  need  proving  to  see  if 
it  has  lost  any  of  its  strength  if  kept  for  a  long 
time,  and  this  may  be  done  by  a  trial  with  a  new 
solution  holding  a  known  amount  of  copper.  Or, 
exactly  the  same  weight  of  crystals  of  sodium  sul- 
phide to  the  same  amount  of  pure  water  may  be 
used  as  before,  and  the  old  solution  thrown  away. 
Or,  by  re-testing  the  sodium  sulphide  the  same  so- 
lution may  be  used  for  a  long  time,  and  if  it  has 


COPPER.  173 

become  weakened,  make  allowance  for  the  addi- 
tional sodium  sulphide  required.  It  should  be  kept 
in  a  cool  place,  out  of  the  sun  and  light  also. 


CHAPTER  IX. 

LEAD    AND    TIN. 

I.  Lead.  It  very  rarely  occurs  native ;  it  then 
has  a  hardness  of  1.5  and  specific  gravity  11.3  to 
11.4.  But  the  most  usual  ore  of  lead  is  the  sulphide 
called  Galena.  When  chemically  pure  it  contains 
86.55  lead  and  13.45  sulphur.  Its  specific  gravity 
is  7.2  to  7.6,  according  to  admixtures.  Streak,  lead- 
gray.  Color,  metallic  lead-gray.  Easily  recognized 
by  the  characteristic  cubical  cleavage  which  is  very 
easily  obtained,  or  granular  structure  when  massive. 
Frequently  associated  with  other  metallic  sulphides 
such  as  pyrite,  chalcopyrite,  arsenopyrite,  blende, 
etc.  It  occurs  in  veins,  the  gangue  of  which  is 
either  quartz,  calcite,  barite  or  fluospar,  in  granite 
and  nearly  all  varieties  of  rock,  but  the  larger 
deposits  are  usually  found  either  in  veins  or  in 
pockets,  often  of  great  size,  in  limestone  strata. 

Galena  almost  always  contains  silver,  and  hence 
all  galenas  should  be  tested  for  silver. 

Test  for  Silver  in  Galena.  Powder  the 
galena  and  dissolve  it  in  strong  nitric  acid  (fuming 
acid  is  best,  which  has  been  described),  then  dip  a 
piece  of  polished  copper  strip  in  the  solution,  and,  if 
silver  exists  in  any  amount,  there  will  be  formed  a 
film  of  silver  on  the  copper.  If  the  thin  film  be- 
(.174) 


LEAD    AND    TIN. 


175 


comes  decidedly  silvery,  and  in  a  short  time,  the  ore 
should  be  laid  aside  for  a  more  careful  analysis. 

The  order  of  strata  in  the  galena  district  of  Wis- 
consin, Illinois  and  Iowa  is  shown  in  the  annexed 
table. 


NIAGARA  LIMESTONE. 

f  Galena  limestone  which  bears  lead. 

1   Trenton  limestone,  fossils. 
P  A  M"R"RO-                                            ' 

«!   Sandstones,  shales,  and  calcareous  beds. 

k                            Lower  magnesian  limestones. 

[      Lower  limit  of  lead. 

WHITE  POTSDAM  SANDSTONE. 

"  Upper — 

Fossiliferous  slates. 

CAMBKIAN  J 

Lower — 

Dolomitic  limestones. 

Dark  sandstones. 

Order  of  Strata  in  the  Lead  District  of  Wisconsin,  Illinois,  and  Iowa. 

The  geology  and  form  of  lodes  of  the  galena  ores 
are  seen  in  Fig.  52. 

Fig.  52. 


Lead  Lode  in  Micaceous; Slate  in  Mine  near  Middletown,  Conn. 


176 


PROSPECTOR  S    FIELD-BOOK    AN'D    GUIDE. 


In  several  regions,  and  extensively  so  in  Colorado, 
a  rich  carbonate  of  lead  has  been  found  (Fig.  53). 

Carbonate  of  Lead  or  Cerussite.  If  perfectly 
pure  its  composition  is,  lead  83.6,  carbonic  acid  16.4. 
As  a  mineral  its  hardness  is  3  to  3.5,  its  specific 

Fig.  53. 


Section  of  strata  in  California  Gulch.  Colorado,  showing  portion 

OF   THE    CAF.BONATE    OF    LEAD    DEPOSITS.      0.    PorphvritiC  TOCk.   12   tO   100   ft. 

thick,  b.  Thin  bed  of  white  clay.  c.  Carbonate  of  lead  bed.  1  to  20  ft.  thick. 
d.  Oxide  of  iron.  1  to  6  ft.  thick,  e,  c.  Limestone.  /.'Clay  slates.  <7,'Quartz- 
ites  and  metamorphic  rocks  resting  upon  gneiss. 


gravity  6.4  to  Q.o.  Color  (if  freshly  broken),  white 
to  gray,  or  even  black,  if  it  has  been  much  weath- 
ered. If  in  good  condition,  it  is  translucent,  or 
even  transparent.  Very  brittle.  If  it  contains 
copper  it  is  usually  tinged  blue  or  green.  It  has  a 
glassy  or  vitreous  appearance,  and  is  easily  melted 
before  the  blow-pipe,  and  a  lead  bead  or  globule  is 
readilv  obtained. 


LEAD    AND    TIN.  177 

By  using  a  little  bone-ash  plastered  in  a  hollow 
in  the  charcoal  and  turning  the  0.  F.  upon  the  lead, 
after  a  little  skillful  blowing  the  lead  is  absorbed 
and  drawn  off  and  a  bright  silver  globule  remains, 
provided  the  lead  contains  silver.  This  is  blow- 
pipe cupelling. 

Sulphate  of  lead  often  accompanies  the  carbon- 
ate. It  somewhat  resembles  the  carbonate,  al- 
though it  is  of  slightly  less  hardness,  2.75  to  3,  spe- 
cific gravity  6.12  to  6.3.  It  may  be  distinguished 
from  the  carbonate  by  the  fact  that  it  does  not  effer- 
vesce in  an  acid,  as  the  latter  always  will.  Its  min- 
eralogical  name  is  anglesite.  It  is  composed  of  lead 
oxide  73.6  and  sulphuric  acid  26.4  in  the  pure 
specimens. 

Phosphate  of  lead.  Mineralogically,  pyromor- 
phite.  Composition,  when  pure,  S9.7  phosphate 
and  10.3  chromate  of  lead,  with  arsenate  of  lead  (0 
to  9),  phosphate  of  lime  (0.11),  and  fluoride  of  cal- 
cium. Hardness,  3.5  to  4:  specific  gravity,  6.o  to  7; 
color,  green  with  modifications.  It  has  a  resinous 
lustre  and  is  translucent;  contains  7S  per  cent.  lead. 
Heated  on  charcoal  before  the  blowpipe  a  globule 
is  formed  which  takes  on  a  crystalline  appearance 
on  cooling,  leaving  a  yellow  oxide  of  lead  on  the 
charcoal.  AVith  carbonate  of  soda  in  the  reducing 
flame  it  yields  a  yellow  globule.  It  is  soluble  in 
nitric  acid. 

Crocoite  or  Chromate  of  Lead   is  a  yellow 
mineral  containing  protoxide  of  lead  68.15,  chromic 
acid  31. 85.     Hardness  2.5  to  3  ;  specific  gravity  5.9 
12 


178      prospector's  field-book  and  guide. 

to  6.1.  Color,  various  shades  of  bright  hyacinth- 
red,  streak  (powder)  orange-yellow.  Lustre,  vitre- 
ous.    Translucent,  and  sectile. 

Massicot  or  Lead  Ochre.  This  mineral  occurs 
massive,  as  a  compact  earth  of  a  sulphury-yellow  or 
reddish-yellow  appearance.  It  has  a  hardness  of  2, 
a  specific  gravity  of  8,  and,  when  pure,  9.2.  It  is 
composed  of  oxygen  7.17,  lead  92.83.  Before  the 
blow-pipe  it  fuses  readily  to  a  yellow  glass,  and  on 
charcoal  is  easily  reducible  to  metallic  lead. 

Lead-Antimony  Ores.  There  are  several  com- 
pounds of  lead  with  antimony,  but  they  are  never 
sufficiently  plentiful  to  be  considered  as  ores.  One 
of  these,  jamesonite,  contains  small  proportions  of 
iron,  copper,  zinc  and  bismuth.  It  occurs  in  gray 
fibrous  masses  or  small  prisms,  and  is  found  in 
Cornwall  associated  with  quartz  and  bournonite. 
Another  of  these  compounds,  zinkenite,  resembles 
stibnite  and  bournonite,  and  occurs  in  an  antimony 
mine  in  the  Hartz. 

The  geology  of  lead.  Almost  all  the  galenas 
and  the  carbonates  contain  silver,  and  some  of  the 
latter,  as  in  Colorado,  contain  large  quantities  of 
silver.  The  geology  of  lead  is  very  much  the  same 
as  that  of  silver. 

The  ores  are  found  in  veins  and  lodes,  and  also 
in  flats  and  beds,  and  in  pockets  (Fig.  54).  The 
galenas  occur  in  limestones,  called  the  "galena 
limestones,"  a  yellowish-gray,  hard,  compact  crys- 
talline rock.  The  lowest  horizon  of  lead  ore  in 
workable  quantities  lies  above  that  of  copper. 


LEAD    AND    TIN. 


179 


"  The  limestones  and  underlying  schists  are,  for 
the  most  part,  in  a  metamorphic  condition,  and 
there  can  be  no  difficulty,  from  the  presence  of 
porphyry  above  and  the  quartzites  and  gneiss 
below,  in  recognizing  their  position,"  *  as  in  the 
Cambro-silurian  system.  It  is  supposed  that  the 
largest  proportion  of  silver  is  contained  in  the  ore 
derived  from  this  geologic  horizon. 

Fig.  54. 


Section  of  Galena  limestone  showing  how  the  lead  occurs  in  lodes,  a, 
flats,  b,  b,  b,  and  pockets,  c,  from  mere  threads  to  several  feet  of  thickness. 


When  water  has  had  its  course,  however,  the 
condition  of  a  mine  and  of  its  veins  and  beds  of  ore 
may  have  been  changed.  Robert  Hunt,  as  it  re- 
gards British  mines,  says,  that  the  circulation  of 
water  in  the  veins  is  affected  by  the  inclination  of 
the  strata  in  the  direction  of  the  vein.  The  richest 
deposits  are  found  in  that  portion  of  strata  which  is 


*  B.  C.  Davies.  F.  G.  S.     A  Treatise  on  Metalliferous  Minerals 
London,  1892,  p.  259. 


180      prospector's  field-book  and  guide. 

the  most  elevated,  for  instance,  on  the  side  of  a 
powerful  cross  vein,  Fig.  55,  thus : 

The  circulation  of  water  is  dependent  upon  an 
outlet  at  a  lower  level. 

In  the  case  of  lead  mines,  it  is  stated  that  in 
consequence  of  the  conditions  connected  with  the 
descent  of  water,  the  richest  deposits  of  lead  are 
generally  found  at  no  great  distance  from  the  out- 
cropping of  the  containing  rock.     Veins  which  run 

Fig.  55. 


on  the  sides  of  a  mountain  in  a  direction  nearly 
parallel  with  the  valleys  contain  more  extensive 
deposits  of  lead  than  those  which  cross  the  valleys 
at  right  angles.* 

The  prospector  should  keep  this  suggestion  in 
mind. 

The  lead  ores  are  found  in  the  fissures  where  they 
seem  to  have  been  deposited  by  waters  which  have 
dissolved  them  out  from  neighboring  beds  (Fig.  56). 

In  the  United  States  the  chief  sources  of  lead  in 
late  years  have  been  argentiferous  ores  and  consid- 
erable from  zinc  ores,  but  a  notable  exception  is 

*  British  Mining,  by  Kobert  Hunt,  London,  1884,  p.  344. 


LEAD    AND    TIN. 


181 


S.  E.  Missouri,  where  galena  accompanied  by  nickel- 
iferous  pyrite  is  disseminated  through  magnesian 
limestone  of  Cambrian  age.  The  mines  are  at 
Bonne  Terre,  Mine  la  Motte  and  Doe  Run.  The 
strata  lie  almost  horizontal,  and  are  known  to  carry 
lead  through  over  300  feet  in  thickness. 

II.  Tin.     When  a  tin-bearing  mineral  is  heated 


Section  op  a  Lead  Deposit  in  a  Fissure  of  the  Limestone.  Williams  & 
Co.'s  Mine,  Wisconsin.  B,  B,  B,  B,  limestone.  A,  the  fissure  running  down. 
C,  C,  C,  C,  masses  of  ore.    Metamorphic. 


before  the  blow-pipe  with  carbonate  of  soda  or  char- 
coal, white  metallic  tin  is  yielded.  By  dissolving 
this  in  hydrochloric  acid  and  adding  metallic  zinc, 
the  tin  will  be  deposited  in  a  spongy  form.  In  the 
blow-pipe  assay  tin  leaves  behind  a  white  deposit 
which  cannot  be  driven  off  in  either  flame.  If  it 
be  moistened  with  nitrate  of  cobalt  solution,  the 
deposit  becomes  bluish-green,  and  this  test  distin- 
guishes it  from  other  metals. 

Assay  of  tin  ore.     If  the  ore  is  poor  it  should  be 
concentrated,  the  vein-stuff  being  got  rid  of  as  much 


182      prospector's  field-book  and  guide. 

as  possible.  If  mixed  with  iron  or  copper  pyrites, 
it  should  be  calcined  or  else  treated  with  acids. 
One  method  is  to  mix  the  ore  with  one-fifth  of  its 
weight  of  anthracite  coal  or  charcoal,  and  expose  it 
in  a  crucible  to  a  great  heat  for  about  twenty  min- 
utes. The  contents  are  then  poured  out  into  an 
iron  mould,  and  the  slag  carefully  examined  for 
buttons. 

Another  method  is  to  mix  100  grains  of  the  ore 
with  six  times  its  weight  of  cyanide  of  potassium, 
and  expose  the  mixture  to  the  heat  of  a  good  fire 
for  twenty  minutes.  The  contents  are  allowed  to 
cool  and  afterwards  broken  to  remove  the  slag. 

Cassiterite  or  Tin  Stone.  This  mineral  forms 
the  principal  source  of  tin,  and  when  pure  contains 
78.6  per  cent,  of  metallic  tin.  It  is  remarkable  for 
its  hardness  (6  to  7),  and  still  more  so  for  its  specific 
gravity  (6.8  to  7).  It  contains  small  quantities  of 
iron,  copper,  manganese,  tungsten,  tantalic  acid, 
arsenic,  sometimes  silica  and  rarely  lime.  It  is 
found  associated  with  quartz,  mica,  topaz,  tourma- 
line, wolfram,  chlorite,  iron  copper,  and  arsenical 
pyrites.  It  occurs  massive  and  in  crystals,  also  in 
botryoidal  and  reniform  shapes,  concentric  in  struct- 
ure and  radiated  fibrous,  and  is  then  in  the  last 
form  called  wood  tin,  from  its  woody  appearance. 
Toad  eye  tin  is  the  last  described,  but  in  very  small 
shot-like  grains.  Stream  tin  is  nothing  but  the  ore 
in  a  state  of  sand  as  it  occurs  along  the  beds  of  the 
streams  or  the  gravel  of  the  adjoining  region.  It 
has  been  derived  from  tin  veins  or  rocks. 


LEAD    AND    TIN.  183 

Cassiterite  yields  a  white,  greyish,  or  brownish 
streak  ;  has  a  brownish  color  and  a  dull  lustre.  It 
is  nearly  as  hard  as  quartz,  and  will  scratch  glass, 
especially  if  freshly  broken.  Pure  crystals  are  rare. 
They  are  nearly  transparent,  but  in  the  mass,  as  it 
occurs  in  the  mines  in  Dakota  and  in  many  other 
places,  the  ore  is  a  dark  brown  color,  and  sometimes 
almost  black  ;  the  fine  powder  or  streak  as  made  by 
a  file,  is  light  brown,  however  dark  the  mineral 
may  be.  The  brown  color  or  shade  is  due  to  oxide 
of  iron  in  composition ;  if  perfectly  free  from  all 
associated  impurities  it  would  be  nearly  white  or 
colorless.  The  usual  appearance  in  mass  or  pebbles, 
or  finer,  is  that  of  a  dirty  or  burned-brown  color 
with  varying  depths  of  shade. 

In  the  pebble  form  it  is  apt  to  wear  quite  smooth, 
due  to  its  extreme  hardness. 

It  was  in  this  form  that  it  was  discovered  in 
Banca,  in  1710,  and  in  the  neighboring  island, 
Billiton,  and  traced  to  its  source  in  the  mountains, 
where  the  central  rock  is  granite,  covered  by  quartz- 
ites,  altered  sand-stones,  and  slaty  rocks.  The 
altered  sandstone  just  above  the  granite  is  the  most 
productive  rock,  and  it  is  traversed  in  all  directions 
with  tourmaline.*  The  same  general  associations 
largely  exist  in  Wyoming  and  Dakota  tin  mines. 

There  is  another  mineral  containing  tin  which 
may  lead  to  the  discovery  of  the  true  ore.  It  re- 
quires only  a  short  description,  which  we  give. 

*  D.  C.  Davies,  F.  G.  S. ,  Metalliferous  Minerals,  London,  1892, 
p.  194. 


184 

Tin  pyrites  (sulphide  of  tin)  whose  composition  is, 
as  a  mineral,  29  to  30  sulphur,  25  to  31  tin,  29  to 
30  copper,  with  iron  and  sometimes  zinc.  It  has 
been  dug  as  an  ore  of  copper  and  called  "  bell- 
metair  Its  hardness  is  4  ;  specific  gravity  4.3  to 
4.5  ;  has  a  metallic  lustre  ;  color,  steel-gray  to  black, 
often  yellowish  from  the  presence  of  copper  sul- 
phide ;  it  is  opaque  and  brittle. 

With  nitric  acid  it  affords  a  blue  solution,  and 
sulphur  and  tin  oxide  separate  and  may  be  tested 
on  charcoal,  where  it  fuses  to  globule,  which,  in 
the  oxidizing  flame,  gives  off  sulphur  and  coats  the 
coal  with  white  oxide  of  tin. 

This  ore  or  mineral,  for  it  does  not  as  yet  deserve 
the  name  of  tin  ore,  is  of  little  use,  but  the  pros- 
pector does  well  to  make  himself  acquainted  with  it, 
as  it  is  frequently  associated  with  the  binoxide  or 
cassiterite,  or  black  oxide,  as  the  true  ore  is  fre- 
quently called. 

In  the  United  States,  cassiterite  occurs  in  small 
stringers  and  veins  on  the  borders  of  granite  knobs 
or  bosses,  either  in  the  granite  itself  or  in  the  adja- 
cent rocks,  in  such  relations  that  it  is  doubtless  the 
result  of  fumarole  action  consequent  on  the  intru- 
sion of  the  granite.  It  appears  that  the  tin  oxide 
has  probably  been  formed  from  the  fluoride.  The 
Cajalco  mine  in  California  and  the  Harvey  Peak 
mines,  South  Dakota,  have  been  developed,  but  it  is 
questionable  whether  they  are  worked  at  a  profit. 
Undeveloped  deposits  are  reported  in  Alabama, 
North  Carolina  and  Virginia.     At  Broad  Arrow, 


LEAD    AND    TIN.  185 

near  Ashland,  Alabama,  tin-ore  is  disseminated  in 
gneiss,  the  ore  averaging  about  1J  per  cent,  black 
tin,  but  being  very  much  mixed  with  titaniferous 
iron.  At  King's  Mountain,  North  Carolina,  cassi- 
terite  occurs  very  irregularly  in  a  (( greisen "  or 
altered  granite,  and  in  limited  alluvials  derived 
from  the  disintegration  of  the  same.  On  Irish 
Creek,  Virginia,  experimental  parcels  of  vein-stone 
taken  from  deposits  in  granite  have  shown  3£  to  3J 
per  cent,  metallic  tin,  largely  associated  with  arsen- 
ical pyrites  and  ilmenite,  which  increase  the  diffi- 
culties of  concentration  and  lower  the  value  of  the 
product. 

Cassiterite  stands  nearly  by  itself  in  its  mode  of 
occurrence  and  formation,  as  a  type  of  a  strongly 
marked  class  of  deposits.  It  is  always  associated 
with  granitic  rocks,  quartz-porphyries,  or  gneiss,  all 
of  which  are  of  analagous  composition,  being  rich  in 
silica,  which  crystallizes  as  quartz,  and  being  called 
in  consequence  "  acidic "  rocks.  Tin  lodes  are 
nearly  all  of  great  antiquity  and  occur  only  in 
those  of  the  above-named  rocks  which  are  charac- 
terized by  the  presence  of  white  mica.  It  is  only 
in  two  or  three  places  in  the  world,  notably  Tus- 
cany and  Elba,  that  granites  of  this  type  have  been 
erupted  during  recent  times,  and  they  contain  tin  in 
small  quantity  as  well  as  some  of  the  minerals 
usually  associated  with  it,  such  as  tourmaline, 
lithia,  mica,  and  emerald. 

Although  this  fact  is  of  no  immediate  practical 
value,  it  is  important,  because  it  shows  that  there 


186      prospector's  field-book  and  guide. 

really  are  laws  which  govern  the  distribution  of 
minerals,  although  these  are  sometimes  very  ob- 
scure ;  but  by  constant  observation  it  is  certain  that, 
amongst  discoveries  of  merely  scientific  interest, 
laws  capable  of  practical  application  will  occasion- 
ally be  found. 

Cassiterite  is  always  associated  with  quartz  and 
rarely  occurs  in  green  rocks,  unless  their  color  be 
due  to  chlorite ;  nor  in  dark-colored  rocks,  except 
where  stained  red  by  the  decomposition  of  ferru- 
ginous minerals  ;  neither  is  it  found  in  limestone. 

Those  granites  which  are  characterized  by  abund- 
ance of  white  mica  have,  with  good  reason,  been 
termed  "tin  granites,"  and  a  coarse-grained  rock 
composed  of  granular  quartz  mixed  with  white  mica 
and  called  "greisen"  occurs  in  all  the  tin  fields  of 
the  world. 

The  minerals  most  commonly  associated  with  tin, 
namely  topaz,  mica,  tourmaline,  fluorspar,  apatite 
and  other  rarer  minerals  containing  fluorine,  seem 
to  show  that  it  was  originally  contained  in  the 
granite  as  fluoride  of  tin,  and  that  the  associated 
minerals  have  been  formed  at  its  expense.  It  is  an 
established  fact  in  the  genesis  of  minerals  that  fluor- 
ine is  always  accompanied  by  silicon  and  boron. 
It  is  therefore  natural  to  find  silicates  containing 
boric  acid,  such  as  tourmaline  and  axinite,  in  asso- 
ciation with  tin.  Other  minerals  which  frequently 
accompany  this  metal  are  wolfram,  molybdenite, 
mispickel,  garnet,  beryl,  etc. 

It  is  evident  that  a  most  important  aid  to  the 


LEAD    AND    TIN.  187 

prospector  is  a  study  of  the  characteristics  of  the 
tinstone  ores,  and  he  may  find  it  beneficial  to  be- 
come acquainted  with  the  special  minerals  above 
mentioned  as  associated  with  the  ores. 

These  minerals  include,  in  some  mines,  wolframite, 
which  gives  trouble  in  the  Cornwall  and  other  tin 
mines,  and  the  following  description  and  tests  may 
aid  in  detecting  it : 

Wolframite  is  in  hardness  5-5.5,  specific  gravity 
7.1-7.55,  therefore,  in  these  features  it  resembles  the 
tin  oxide ;  though  somewhat  softer,  yet  the  specific 
gravity  is  practically  the  same,  although  really 
heavier.  So  in  color  it  frequently  closely  resembles 
tin  oxide.  But  in  the  streak  (or  scratch  powder), 
wolframite  is  a  dark  reddish-brown  to  black,  while 
the  tin  oxide  gives  a  white  or  grayish-brown  pow- 
der ;  wolframite  is  opaque,  while  the  tin  oxide  is 
translucent  and  sometimes  transparent  on  the  edges  ; 
when  mixed  with  iron  or  manganese  rarely,  it  looks 
almost  opaque.  Composition  of  wolframite  :  Tnng- 
stic  acid  about  75,  the  remainder  protoxide  of  iron 
and  manganese  protoxide,  more  of  the  latter  than 
of  the  former. 

Wolframite  is  used  in  the  preparation  of  some 
colors  and  enamels,  and  enters  into  the  composition 
of  some  special  kind  of  steel.  Tungstate  of  soda 
which  is  used  as  a  mordant  and  for  fire-proofing 
fabrics,  is  also  prepared  from  it. 


CHAPTER  X. 


ZINC    AND    IRON. 


I.  Zinc.  Zinc  is  never  found  free  in  nature,  but 
chiefly  occurs  in  combination  with  carbonic  acid  and 
united  with  sulphur.     The  chief  ores  are  : 

Smithsonite  or  zinc  carbonate.  Composition, 
zinc  51.44,  oxygen  13.10,  carbonic  acid  35.46.  But 
the  composition  in  the  mines  varies  because  of  the 
presence  of  protoxide  of  iron,  manganese  and  mag- 
nesia. Color,  when  pure,  nearly  white,  through 
various  shades  of  yellow  and  gray  to  brown.  Hard- 
ness 5 ;  specific  gravity  4-4.4.  Streak,  uncolored 
or  white.  Lustre,  vitreous,  pearly,  subtransparent 
to  translucent.  Found  in  veins,  but  more  usually 
in  irregular  deposits  in  limestone  strata. 

It  is  easily  detected  by  the  blow-pipe,  as  it  gives  a 
green  color  when  heated  after  being  moistened  with 
half  a  drop  of  nitrate  of  cobalt  solution.  On  char- 
coal, with  soda,  it  coats  the  charcoal  with  a  white 
film,  which  is  yellow  when  hot  and  white  on  cool- 
ing, but  if  moistened  with  the  cobalt  solution  and 
heated  in  the  0  F  it  turns  green.  "With  muriatic 
acid  it  effervesces  and  dissolves.  In  mass  it  is 
translucent  and  brittle. 

Calamine.  This  is  a  silicate  of  zinc.  Composi- 
(188) 


ZINC    AND    IRON.  189 

tion,  zinc  oxide  67.5,  silica  25,  water  7.5.  Hardness 
4.5-5,  the  latter  when  crystallized  (Dana);  specific 
gravity  3.16-3.9.  Color  and  streak  the  same  as  in 
Smithsonite.  Acts  before  the  blow-pipe  as  does 
Smithsonite,  but  does  not  effervesce  with  acids,  and 
gelatinizes  ;  it  is  soluble  in  a  strong  solution  of  pot- 
ash. In  physical  characters  zinc  silicate  somewhat 
resembles  zinc  carbonate.  An  anhydrous  variety  of 
this  ore  is  Willemite,  which  is  found  in  New  Jersey 
(Mine  Hill  and  Sterling  Hill).  Zinc  silicate  is  usu- 
ally found  in  veins  or  in  beds  or  in  irregular  pock- 
ets in  stratified  calcareous  rocks,  in  association  with 
zinc  blende,  zinc  carbonate,  iron,  lead  ores,  etc. 

Zincite  on  red  oxide  of  zinc.  Its  composi- 
tion is  zinc  80,  oxygen  20,  varied  by  the  presence 
of  3  to  12  parts  of  peroxide  of  manganese,  which 
gives  the  red  color,  for  zinc  oxide,  pure,  is  white. 
The  ore  is  peculiar  to  one  region  in  New  Jersey, 
Franklin,  Sussex  Co.  Hardness  4-4.5 ;  specific 
gravity  5.4-5.7  ;  color,  red  and  yellowish-red,  streak 
the  same  ;  translucent,  brittle. 

Sulphide  of  zinc,  mineralogical  name  sphalerite 
or  blende,  miners'  name  black-jack.  Composition, 
zinc  66.8,  sulphur,  33.2,  but  varied  in  the  mines  by 
iron,  and  sometimes  cadmium.  Color  varies  from 
yellow  to  brown  and  almost  black,  having  a  waxy 
look.  Hardness  3.5  to  4;  specific  gravity  3.9  to  4.2; 
brittle,  translucent.  Zinc  blende  is  the  most  abun- 
dant zinc  ore.  It  occurs  in  rocks  of  all  ages,  in 
veins,  in  contact  deposits  or  in  irregular  pockets  in 
limestone,   etc.,  and  is  frequently  associated  with 


190 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


the  ores  of  lead,  as  well  as  those  of  copper,  iron,  sil- 
ver, gold  and  tin ;  also,  frequently  associated  with 
quartz,  barite,  fluorite,  calcite,  etc.  It  is  easily  re- 
cognized if  treated  with  hot  hydrochloric  acid,  as 
it  gives  a  smell  of  rotten  eggs  (sulphuretted  hydro- 
gen), and  the  same  results  can  be  obtained  without 
heating  if  a  small  quantity  of  pure  iron  filings  is 
added  to  the  acid.  With  soda  on  charcoal  before 
the  blow-pipe,  zinc  blende  gives  a  sulphuret  which, 
with  water  on  a  silver  coin,  tarnishes  or  blackens  it. 
The  geology  of  zinc  and  of  lead  are  so  nearly 

Fig.  57. 


Section  of  strata  near  Sparta,  New  Jersey,  zinc  mines. 
a,  Slaty  rock  with  feldspathic  dykes,    b,  b,  Limestone,    c,  Franklinite  iron 
ore  with  zinc  20  to  30  ft.  wide,    d,  Red  oxide  of  zinc  3  to  9  ft.  wide,    e,  e, 
Crystalline  limestone.   /,  Feldspathic  rock. 

alike  that  what  has  been  said  of  the  latter  will  apply 
to  the  former  (Fig.  57). 

In  New  Jersey  a  section  of  strata  near  Sparta 
shows  slaty  rock  with  feldspathic  dykes,  then  lime- 
stone adjoining  the  Franklinite  iron  ore  with  zinc 
20  to  30  feet  wide,  then  the  red  oxide  of  zinc  3  to  9 
feet  wide,  then  crystalline  limestone,  and  next  feld- 
spathic rock  (Fig.  57). 


ZINC   AND    IRON.  191 

Enormous  and  extensive  deposits  of  the  sulphide 
are  reported  as  occurring  in  Colorado,  at  George- 
town and  Mount  Lincoln,  and  in  Montana,  near 
Jefferson  City. 

The  blow-pipe  shows  the  same  tests  for  zinc  as 
have  previously  been  mentioned.  The  fumes  of 
sulphurous  acid  may  be  easily  noticed  when  the 
mineral  is  placed  in  an  open  tube  of  glass  (a  test 
tube  with  a  small  hole  in  the  bottom  will  be  suffi- 
cient), and  is  strongly  heated. 

II.  Iron.  This  metal  is  one  of  the  most  abundant 
and  widely  disseminated  elements  of  the  earth's 
crust,  its  distribution  being  materially  aided  by  the 
fact  of  its  forming  two  oxides  of  different  chemical 
quantivalence.  Native  iron  is  not  found  in  nature, 
but  occurs  with  a  small  percentage  of  nickel  in 
meteorites.  It  resembles  ordinary  iron,  is  malleable 
and  attracted  by  a  magnet.  Specific  gravity  7.0  to 
7.8. 

The  chief  ores  of  iron  are  magnetite,  hematite 
(red  and  brown),  and  black  band. 

Magnetite  or  magnetic  iron  ore,  is  found  in 
octahedral  or  decahedral  crystals ;  more  commonly 
simply  massive.  Streak  black  ;  color,  black.  Com- 
position, iron  72.4,  oxygen  27.6.  Hardness,  5.5  to 
6.5 ;  specific  gravity,  5  to  5.1.  The  ore  is  always 
easily  attracted  by  the  magnet,  and  sometimes  is 
found  capable  of  attracting  iron  and  is  then  called 
polaric  or  loadstone.  In  powder  or  small  grains  it 
is  always  attractable  by  a  magnetized  knife  blade. 

The  usual  geological  position  of  magn^tite'is  in 


192      prospector's  field-book  and  guide. 

the  most  highly  met  amorphic  rocks,  in  which  it 
probably  represents  the  excess  of  iron  oxide  origi- 
nally in  the  rock  which  was  not  taken  up  by  silica. 
Occasionally  it  is  found  in  layers,  but  in  this  coun- 
try and  elsewhere  it  forms  whole  mountains. 
Among  other  rocks  in  which  it  occurs  the  following 
are  the  most  important :  Crystalline  limestone,  chlor- 
ide, talcose,  hornblendic,  pyroxenic  and  hypers- 
thenic schists ;  serpentine,  diorite  and  basalt.  Spec- 
ular iron  is  frequently  associated  with  it. 

Magnetite  is  not  acted  upon  by  nitric  acid,  but 
hydrochloric  acid  dissolves  it  when  in  very  fine 
powder,  and  under  long-continued  heat. 

Iron  exists  in  magnetite  as  protoxide  and  per- 
oxide or  FeO  and  Fe203,  and  upon  this  difference 
of  oxides  is  based  the  action  of  important  tests. 

Franklinite  is.  an  ore  somewhat  resembling 
magnetite  in  color,  hardness,  and  specific  gravity, 
but  it  contains  manganese  and  zinc,  and  as  an  ore, 
is  peculiar  to  Sussex  Co.,  New  Jersey.  Its  streak  is 
dark  brown,  and  its  action  on  the  magnet  is  feebler 
than  in  the  case  of  magnetite.  The  iron  is  said  to 
be  of  the  composition  of  peroxide,  or  Fe203,  but  it 
is  probably  in  part  protoxide,  and  this  is  the  cause 
of  its  feeble  effect  on  the  magnet. 

It  is  easily  affected  under  the  blow-pipe.  Alone, 
it  is  infusible,  but  with  borax  in  the  0  Fit  colors 
the  borax  bead  with  the  amethystine  color  of  man- 
ganese, and  in  the  R  F  it  shows  the  bottle-green  of 
iron.  On  charcoal  with  soda  it  gives  the  bluish- 
green  manganate,   and   also  the   coating   of  zinc, 


ZINC    AND    IRON.  193 

especially  if  the  soda  is  mixed  with  borax.  It  is 
soluble  in  fine  powder  in  muriatic  acid. 

Specular  ore  is  the  peroxide  of  iron  without  the 
protoxide.  This  oxide  is  also  called  the  sesqui- 
oxide,  or  one  and  a  half  oxides,  since  iron  combines 
with  oxygen  in  the  proportion  of  one  to  one  and  a 
half  parts,  or  Fe203,  and  this  is  the  highest  propor- 
tion of  oxygen  the  iron  will  combine  with,  and 
hence  it  is  the  peroxide,  the  peroxide  and  sesqui- 
oxide  being  the  same  in  this  case. 

Specular  ore  is  called  red  hematite  from  its 
color,  which  in  some  masses  is  so  intensely  red  as  to 
appear  nearly  black,  but  it  may  always  be  distin- 
guished from  magnetite  by  its  red  streak,  and  the 
blacker  the  ore  the  more  decided  is  the  red  of  its 
powder  or  streak.  It  is  never  magnetic.  We  have 
always  found  that  in  cases  where  specular  ore 
showed  any  magnetic  attraction,  it  was  due  to  the 
fact  that  the  ore  contained  some  protoxide  of  iron. 

Hardness  5.5;  specific  gravity  4.5  to  5.3;  composi- 
tion, 70  per  cent,  iron,  30  per  cent,  oxygen.  Color, 
reddish  to  almost  black. 

Brown  Iron  Ore  or  Brown  Hematite  or 
Limonite.  This  is  the  same  composition  as  red 
hematite,  except  that  it  has  less  iron  and  contains 
water  in  chemical  combination,  generally  about  14 
per  cent.  Color  always  brown.  When  heated  red- 
hot  it  loses  its  water  and  turns  to  a  bright-red,  unless 
largely  mixed  with  alumina  and  silex,  when  the 
red  color  is  shaded.  It  is  not  magnetic  unless 
13 


194      prospector's  field-book  and  guide. 

heated  with  soda  under  the  blow-pipe,  when  it  be- 
comes metallic,  as  all  iron  ores  do. 

The  amount  of  metallic  iron  in  a  pure  specimen 
is  59  per  cent.,  sometimes  decreased  by  the  presence 
of  alumina,  silica,  magnesia,  and  other  impurities,  so 
that  its  average  in  many  good  mines  is  only  about 
35  to  36  per  cent.  iron. 

Spathic  Iron  Ore  or  Siderite  is  an  iron  car- 
bonate, composed  of  iron  protoxide  62  per  cent,  and 
carbonic  acid,  or  48  per  cent,  pure  iron.  Hardness 
3.5  to  4.5  ;  gravity  3.7-3.9 ;  streak  white.  Color 
gray  or  cream  color,  unless  weathered,  when  it  is 
brownish. 

When  in  powder  it  effervesces  with  muriatic  acid, 
especially  when  hot.  Translucent  on  edges,  and 
thin  plates  or  splinters. 

With  the  blow-pipe  in  a  closed  tube  (test  tube)  it 
decrepitates,  becomes  blackened,  and  gives  off  car- 
bonic acid.  Before  the  blow-pipe  alone,  held  by 
forceps,  it  blackens  and  fuses.  In  the  test-tube  with 
muriatic  acid  it  may  be  tested  for  carbonic  acid,  by 
letting  a  lighted  thread  down  into  the  tube,  when 
the  flame  is  instantly  extinguished.  The  solution 
in  the  tube  may  be  tested  for  iron  by  dropping  a 
drop  of  solution  of  ferri cyanide  of  potassium  into  the 
muriatic  acid  solution,  when  it  becomes  instantly  a 
deep  blue.  This  is  a  test  of  protoxide  of  iron,  spathic 
ore  being  iron  in  the  condition  of  protoxide  only. 

Black  band  ore  is  an  argillaceous  spathic  ore  of 
various  dark  colors,  being  largely  combined  with 
carbonaceous  material.     It  is  found  extensively  in 


ZINC    AND    IRON.  195 

Great  Britain,  near  the  summit  of  the  coal  measures. 
In  our  country  the  black  band  ores  are  also  associ- 
ated with  the  coal  measures,  both  in  the  anthracite 
and  bituminous  regions. 

Chromic  Iron  or  Chromite,  generally  with  49.90 
to  60.04  per  cent,  of  chromic  oxide,  18.42  to  35.68 
per  cent,  of  ferrous  oxide,  10  to  12  per  cent,  alumina, 
5.36  to  15  per  cent,  magnesia,  and  4  to  6  per  cent, 
silica,  occurs  usually  massive,  mixed  with  other  iron 
ores  or  in  serpentine.  It  is  of  an  iron-black  to  brown- 
ish-black color  and  a  faintly  metallic  lustre.  Streak 
or  powder,  dark-brown.  Fracture,  irregular;  specific 
gravity,  4.4  to  4.6;  hardness  5.5,  is  not  scratched  by 
a  knife.  With  borax  bead  it  gives  the  character- 
istic indications  of  chromium.  It  is  largely  used  in 
the  preparation  of  chromium  colors. 

The  following  iron  ores  are  not  used  for  the  mak- 
ing of  iron  and  steel,  but  may  nevertheless  prove  of 
value. 

Iron  Pyrites,  usually  in  cubes  and  allied  forms, 
sides  often  marked  by  fine  parallel  lines.  Occurs 
also  massive  and  contains  46.7  per  cent,  of  iron  and 
53.3  per  cent,  of  sulphur.  Color,  brass  yellow ; 
lustre,  metallic ;  streak,  brownish-black ;  fracture 
irregular  ;  specific  gravity  4.8  to  5.1 ;  hardness  6  to 
6.5 ;  cannot  be  scratched  with  a  knife,  but  is 
scratched  by  quartz,  and  scratches  glass  with  great 
facility.  Before  the  blow-pipe  it  burns  with  a  blue 
flame,  giving  off  an  odor  of  sulphur,  and  ultimately 
fuses  into  a  black  magnetic  globule.  It  is  found  in 
great  abundance,  and  is  used  as  a  source  of  sulphur. 


It  is  easily  distinguished  from  -copper  pyrites  by  its 
hardness,  the  latter  being  readily  cut  with  a  knife. 
From  gold  it  is  distinguished  by  its  hardness  and  in 
not  being  malleable,  and  in  giving  off  sulphurous 
odors  in  the  blow-pipe  flame. 

Arsenical  Pyrites  or  Mispickel  contains  34.4 
per  cent,  of  iron,  19.6  per  cent,  of  arsenic,  and  46.0 
per  cent,  of  sulphur.  It  occurs  in  flattened  prisms 
and  also  massive.  Color,  white ;  lustre,  metallic ; 
streak,  gray ;  fracture,  uneven ;  specific  gravity  6.0 
to  6.3 ;  hardness  5.5  ;  cannot  be  scratched  with  a 
knife,  but  is  scratched  by  quartz.  Heated  before 
the  blow-pipe  it  gives  off  white  arsenical  fumes  of  a 
garlic  odor,  and  finally  fuses  into  a  black  globule. 
It  is  abundant  in  mining  districts,  and  sometimes  is 
auriferous.  With  the  improved  processes  now  in 
use,  it  is  possible  to  extract  the  gold  profitably,  and 
hence  mispickel  ores  should  be  examined  for  gold. 

The  Geology  of  the  iron  ores  varies  and  may  be 
divided  into  that  of  the  magnetites,  which  are  al- 
ways derived  from  the  granites,  gneiss,  schist  rocks, 
clay  slates,  and,  rarely,  the  metamorphic  limestones. 

The  red  hematites  seem  to  be  only  an  alteration 
derived  from  the  magnetites,  and  belong  to  the 
same  more  ancient  rocks  as  the  latter. 

The  brown  hematites  (limonites)  are  derived  from 
both  the  former  and  are  generally  sedimentary. 

Very  frequently  in  extensive  magnetic  regions, 
where  the  country  back  is  mountainous,  the  brown 
ore  has  been  formed  in  basins  and  knees  and  inter- 
locked portions  of  the  lower  country,  where  ages  of 


ZINC    AND    IRON. 


197 


rains,  storms  and  freshets  have  gradually  trans- 
ported and  altered  the  magnetic  ores  of  the  upper 
regions  and  brought  down  these  iron  oxides  to  the 
low  lands,  where  they  have  been  arrested  and  set- 
tled down  in  beds  of  brown  hematite.  This  seems 
to  have  been  the  history  of  all  the  hematitic  limonite 

Fig.  58. 


Geological  Horizons  around  the  Iron  Ores  op  Lake  Superior. 
a.  Gneiss,    b,  Hornblende  slates,    c.  The  same  with  numerous  thin  beds 
of  iron  ore  which  frequently  unite,    d.  Potsdam  sandstone. 


beds  and  deposits ;  they  are  on  the  lower  levels 
when  they  were  formed,  although  in  after  ages  they 
may  have  been  uplifted. 

Iron  ores  are,  therefore,  to  be  found  in  three  gen- 
eral geologic  regions :  (1)  in  the  earliest  rocks ;  (2) 
in  the  carboniferous,  and  (3)  in  the  more  recent  or 
sedimentary    rocks,   and  in  accordance  with  their 


198 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


composition  as  magnetites  and  specular  ores,  as 
carbonaceous  or  black  band  and  spathic  ores,  or  as 
brown  ores  of  the  limonite  order. 

One  of  the  most  peculiar  geologic  conditions  is 


Fig. 


<*W 


North 


1)  a 

Section  of  Pilot  Knob,  Missouri. 
a.  Quartzite  or  siliceous  rock.    b.  Red  hematite  iron  ore  alternating  with 
siliceous  matter,    c.  Siliceous  rocks. 

found  in  the  Pilot  Knob  Mountain,  wherein  the 
iron  strata  have  been  thrown  up  as  in  Fig.  59. 

THE  USE  OF  THE  MAGNETIC    NEEDLE    IN    PROSPECTING 
FOR  IRON. 

In  ordinary  cases,  where  the  surface  is  covered 
with  loose  earth,  it  is  common  to  search  for  mag- 
netic iron  ore  with  a  magnetic  needle  or  a  miner's 
compass,  and  for  preliminary  examinations  it  is 
now  the  chief  reliance.  In  using  this  instrument 
considerable  practice  is  required  ;  but  this  joined  to 
good  judgment  gives  indications  of  the  presence  of 
ore  which  are  almost  infallible.  There  has  been 
very  great  improvement,  within  a  few  years  past,  in 


ZINC    AND    IRON.  199 

the  methods  of  searching  for  magnetic  ore  as  well 
as  in  the  instruments  to  be  used  for  that  purpose, 
and  the  work  is  now  well  done  by  many  persons. 

In  the  Annual  Keport  of  the  State  Geologist  of 
New  Jersey  for  1879,  W.  H.  Scranton,  M.  E.,  makes 
a  report,  accompanied  by  a  map,  upon  a  magnetic 
survey  made  at  Oxford,  Warren  Co.,  New  Jersey,  to 
determine  the  location  of  a  vein,  and  the  proper 
places  to  sink  shafts.  Mr.  Scranton  finds  Gurley's 
Norwegian  compass  the  best,  though  the  slowest  to 
work  with.  He  sums  up  the  indications  from  the 
magnetic  needle  in  searching  for  ore,  as  it  usually 
occurs  in  New  Jersey,  as  follows : 

"  An  attraction  which  is  confined  to  a  very  small 
spot  and  is  lost  in  passing  a  few  feet  from  it,  is  most 
likely  to  be  caused  by  a  boulder  of  ore  or  particles 
of  magnetite  in  the  rock. 

"  An  attraction  which  continues  on  steadily  in  the 
direction  of  the  strike  of  the  rock  for  a  distance  of 
many  feet  or  rods,  indicates  a  vein  of  ore  ;  and  if  it 
is  positive  and  strongest  towards  the  southwest,  it  is 
reasonable  to  conclude  that  the  vein  begins  with  the 
attraction  there.  If  the  attraction  diminishes  in 
going  northeast,  and  finally  dies  out  without  becom- 
ing negative,  it  indicates  that  the  vein  has  con- 
tinued on  without  break  or  ending  until  too  far  off 
to  move  the  compass  needle.  If,  on  passing  towards 
the  northeast,  along  the  line  of  attraction,  the  south 
pole  is  drawn  down,  it  indicates  the  end  of  the  vein 
or  an  offset.  If,  on  continuing  further  still  in  the 
same  direction,  positive  attraction  is  found,  it  shows 


that  the  vein  is  not  ended ;  but  if  no  attraction  is 
shown,  there  is  no  indication  as  to  the  further  con- 
tinuance of  the  ore. 

"  In  crossing  veins  of  ore  from  southeast  to  north- 
west, when  the  dip  of  the  rock  and  ore  is  as  usual  to 
the  southeast,  positive  attraction  is  first  observed  to 
come  on  gradually,  as  the  ore  is  nearer  and  nearer 
to  the  surface,  and  the  northwest  edge  of  the  vein  is 
indicated  by  the  needle  suddenly  showing  negative 
attraction  just  at  the  point  of  passing  off  it.  This 
change  of  attraction  will  be  less  marked  as  the 
depth  of  the  vein  is  greater,  or  as  the  strike  is  nearer 
north  and  south.  The  steadiness  and  continuance 
of  the  attraction  is  a  much  better  indication  of  ore 
than  the  strength  or  amount  of  attraction  is.  The 
ore  may  vary  in  its  susceptibility  to  the  magnetic 
influence  from  impurities  in  its  substance ;  it  does 
vary  according  to  the  position  in  which  it  lies — 
that  is,  according  to  its  dip  and  strike ;  and  it  also 
varies  very  much  according  to  its  distance  beneath 
the  surface. 

"  Method  of  Using  the  Compass  in  Searching  for  Ore. 
— It  is  sufficient  to  say  that  the  first  examinations 
are  made  by  passing  over  the  ground  with  the  com- 
pass in  a  northwest  and  southeast  direction,  at  in- 
tervals of  a  few  rods,  until  indications  of  ore  are 
found.  Then  the  ground  should  be  examined  more 
carefully  by  crossing  the  line  of  attraction  at  inter- 
vals of  a  few  feet,  and  marking  the  points  upon 
which  observations  have  been  made,  and  recording 
the  amount  of  attraction.     Observations  with  the 


ZINC    AND    IRON.  201 

ordinary  compass  should  be  made  and  the  varia- 
tion of  the  horizontal  needle  be  noted.  In  this  way 
material  may  soon  be  accumulated  for  staking  out 
the  line  of  attraction,  or  for  constructing  a  map  for 
study  and  reference. 

"  After  sufficient  exploration  with  the  magnetic 
needle,  it  still  remains  to  prove  the  value  of  the 
vein  by  uncovering  the  ore,  examining  its  quality, 
measuring  the  size  of  the  vein,  and  estimating  the 
cost  of  mining  and  marketing  it.  Uncovering 
should  first  be  done  in  trenches  dug  across  the 
line  of  attraction,  and  carried  quite  down  to  the 
rock.  When  the  ore  is  in  this  way  proved  to  be  of 
value,  regular  mining  operations  may  begin. 

"  In  places  where  there  are  offsets  in  the  ore,  or 
where  it  has  been  subject  to  bends,  folds,  or  other 
irregularities,  so  that  the  miner  is  at  fault  in  what 
direction  to  proceed,  explorations  may  be  made  with 
the  diamond  drill." 


CHAPTER  XI. 

MERCURY,  BISMUTH,  NICKEL,  COBALT,  AND    CADMIUM. 

I.  Mercury  or  Quicksilver.  At  ordinary  tem- 
peratures it  is  fluid,  a  character  which  no  other 
metal  possesses.  The  usual  properties  of  a  metal 
are,  however,  highly  developed  in  it,  and  when 
solid  it  has  much  resemblance  to  silver,  especially 
in  its  high  metallic  lustre,  ductility,  malleability, 
its  capability  of  being  cut  with  a  knife,  its  granular 
fracture,  and  its  high  degree  of  conductibility  of 
heat  and  electricity.  It  is  sometimes  found  native, 
either  as  globules  disseminated  through  its  ores,  or 
in  rocks  containing  them.  It  is  bright  white  and 
of  specific  gravity  13.6  at  50°  F.,  and  about  15.6 
when  solid. 

Mercury  readily  combines  with  most  of  the  other 
metals,  and  the  compounds  thus  formed  are  called 
amalgams.  The  amalgams  with  the  heavy  elements 
are  generally  easy  of  decomposition,  and  hence  it  is 
exceedingly  useful  for  the  extraction  of  gold  and 
silver  from  their  ores  or  matrices.  The  mercury 
picks  up  the  almost  invisible  specks  of  gold,  and  in 
this  way  the  gold  is  concentrated  into  a  compara- 
tively small  space.  By  heating  the  amalgam  the 
mercury  is  driven  off  and  the  gold  is  separated  in 
nearly  pure  form. 

(202) 


MERCURY,  BISMUTH,  NICKEL,  ETC.  203 

Mercury  is  most  commonly  found  in  association 
with  sulphur.  Antimony  is  also  a  frequent  com- 
panion, but  not  in  chemical  union.  The  ore  of 
greatest  industrial  importance  is 

Cinnabar,  or  sulphide  of  mercury,  found  massive, 
of  a  granular  texture,  reddish  color,  and  scarlet-red 
streak.  Composition  :  Mercury  86.2,  sulphur  13.8, 
when  pure.  It  is  the  only  regular  and  most  valu- 
able ore  of  mercury. 

Hardness  2  to  2.5  ;  specific  gravity  8.99  ;  sectile. 
Easily  scratched  with  a  knife,  affording  a  deep  red 
streak.  Before  the  blow-pipe  on  charcoal  it  is  vola- 
tile if  pure,  gives  sulphurous  fumes  if  heated  in  an 
open  tube,  and  mercury  condenses  on  the  sides  of 
the  tube,  so  that  it  may  easily  be  seen  with  a  lens 
or  even  the  naked  eye. 

There  is  also  a  black  sulphide,  called  metacinna- 
barite,  found  in  one  locality  in  California ;  and,  in 
California  and  Mexico,  a  sulphoselenide  named 
guadalcazarite  (81J  per  cent,  mercury,  10  sulphur, 
6J  selenium)  is  sometimes  encountered. 

Native  Amalgams.  Only  two  native  amalgams 
are  known,  namely,  those  with  silver  and  gold.  As 
in  all  alloys  the  proportions  of  the  constituents  vary, 
and  the  properties  of  a  specimen  will  vary  according 
as  the  silver,  the  gold  or  the  mercury  predominates. 
The  native  amalgam  most  frequently  found  is  a 
mixture  of  silver  and  mercury,  and  when  pure  con- 
tains from  64  to  72  per  cent,  mercury.  Color,  sil- 
ver white ;  hardness,  3  to  3.5  ;  specific  gravity  10.5 
to  14.  On  charcoal  before  the  blow-pipe,  the  mer- 
cury evaporates,  and  the  silver  remains. 


The  quicksilver  deposits  at  Aim  ad  en,  in  Spain, 
have  a  far  remote  history,  for  in  the  time  of  Pliny 
10,000  lbs.  were  sent  annually  to  Kome  from  these 
mines.  They  occur  in  upper  Silurian  slates,  some- 
times interstratified  with  beds  of  limestone  ;  but  the 
ordinary  slates  themselves,  which  are  much  con- 
torted, rarely  contain  cinnabar.  The  enclosing 
rock  usually  consists  of  black  carbonaceous  slates 
and  quartzites  alternating  with  schists  and  fine- 
grained sandstones. 

At  Idria,  Austria,  cinnabar  is  found  in  impreg- 
nated beds  and  stockworks,  in  bituminous  shales, 
dolomitic  sandstones  and  limestone  breccias  of  tri- 
assic  age,  dipping  30°  to  40°,  and  covered  by  car- 
boniferous sandstones  and  shales  in  a  reversed 
position.  This  deposit  has  been  worked  for  nearly 
400  years,  and  is  said  to  become  richer  as  the  depth 
increases. 

The  quicksilver-bearing  belt  of  California  extends 
along  the  coast  range  for  a  distance  of  about  200 
miles.  According  to  a  report  by  M.  G.  Holland, 
these  deposits  are  generally  impregnations  in  the 
cretaceous  and  tertiary  formations.  They  seem  to 
be  richer  when  the  beds  are  more  schistose  and 
transmuted.  They  are  more  or  less  closely  in  rela- 
tion with  serpentines,  which  are  themselves  some- 
times impregnated  with  oxide  of  iron,  sometimes  in 
quartzose  schists,  in  sandstones,  more  rarely  in 
limestone  rocks,  limestone  breccias,  etc.  Native 
mercury  is  found  in  some  magnesian  rocks  near  the 
surface.     There  are  no  defined  fissures  nor  veins 


MERCURY,  BISMUTH,  NICKEL,  ETC.  205 

proper.  The  cinnabar  with  quartz,  pyrites,  and 
bituminous  substances  is  sometimes  disseminated  in 
the  rock  in  fine  particles  and  spots,  sometimes  forms 
certain  kinds  of  stockworks  or  reticulated  veins  and 
nests.  The  parts  thus  impregnated  congregate  and 
form  rich  zones,  the  size  of  which  occasionally 
reaches  80  fathoms,  and  the  percentage  35  per  cent., 
and  flat-like  veins  or  lenticular  deposits,  the  strike 
and  dip  of  which  agree  with  those  of  the  schists  of 
the  country  generally.  These  rich  zones  without 
denned  limits  gradually  merge  into  poor  stuff  con- 
taining half  a  per  cent.,  or  more  traces,  and  are  of 
no  value. 

Sulphur  Bank,  one  of  the  principal  mines,  was 
originally  worked  as  a  sulphur  deposit.  Sulphur 
in  workable  quantities  is  known  to  exist  in  some 
volcanic  countries,  and  volcanic  rocks  are  abundant 
at  the  California  cinnabar  mines. 

II.  Bismuth.  This  metal  occurs  native,  of  a  red- 
dish silver-white  color.  Brittle  when  cold  ;  hard- 
ness 2-2.5 ;  specific  gravity  9.7.  Malleable  and 
sectile  when  heated,  but  breaks  under  the  hammer. 
It  carries,  sometimes,  traces  of  arsenic,  sulphur,  tel- 
lurium and  iron.  On  charcoal  before  the  blow-pipe, 
it  fuses  and  entirely  volatilizes,  leaving  a  coating 
which  is  orange-yellow  while  hot  and  lemon-yellow 
on  cooling  (this  is  the  trioxide  of  bismuth).  It  dis- 
solves in  nitric  acid,  but  subsequent  dilution  causes 
a  white  precipitate. 

Very  little  bismuth  has  been  found  in  our  coun- 
try.    The  metal  occurs  on  the  Continent  of  Europe, 


206      prospector's  field-book  and  guide. 

associated  with  silver  and  cobalt,  also  with  copper 
ores.  Although  there  is  but  little  call  for  it  in  the 
arts,  a  deposit  or  lode  of  bismuth  would  be  valuable. 

Where  it  has  been  found  in  the  United  States  it 
has  been  associated  with  wolfram  (tungstate  of  iron 
and  manganese),  also  with  tungstate  of  lime,  with 
galena  and  zinc  blende  in  quartz. 

Its  Geology  is  the  same  as  that  of  copper ;  it 
occurs  in  veins  in  gneiss  and  other  crystalline  rocks 
and  clay  slate,  accompanying  ores  of  silver,  copper, 
lead  and  zinc. 

III.  Nickel.  It  does  not  occur  native  except  in 
meteorites. 

Under  the  blow-pipe,  nickel  requires  care  and 
some  practice.  On  charcoal,  with  soda  in  the  inner 
flame,  it  gives  a  gray  metallic  powder,  attractable 
by  the  magnet.  In  the  borax  bead  in  the  outer 
flame  it  gives  a  hyacinth-red  to  violet-brown  while 
hot,  a  yellowish  or  yellow-red  when  cold.  In  the 
reducing  or  inner  flame,  a  gray  appearance  is  given. 
These  appearances  are  modified  by  the  impurities 
and  the  amount  of  nickel  in  the  mineral.  The  wet 
process  is  the  only  method  of  determining  the  true 
value  of  a  nickel-bearing  mineral. 

Its  chief  ores  are  : 

Smaltite,  which  is  a  combination  of  cobalt,  iron 
and  nickel,  and  arsenic  in  varying  proportions.  It 
will  be  more  fully  referred  to,  later  on,  under 
Cobalt. 

Nickel  arsenide,  " copper  nickel"  mineralogical 
name,  nicolite.     Composition  :  nickel  44.1 ;  arsenic 


207 

55.9.  It  looks  somewhat  like  pale  copper,  but  con- 
tains no  copper.  Hardness  5-5.5,  specific  gravity, 
6.67-7.33  ;  streak,  pale  brownish  to  black  ;  brittle. 
It  frequently  contains  a  little  iron,  and  sometimes  a 
trace  of  antimony,  lead  and  cobalt. 

If  carefully  treated  under  the  blow-pipe  with 
borax,  it  will  show  the  iron  if  present,  in  the  bead, 
and  the  cobalt  and  nickel  by  successive  oxidations 
(see  under  Smaltites  later  on).  But  the  nickel  re- 
quires especial  treatment,  the  detection  of  which  we 
will  speak  of  in  this  chapter. 

There  is  another  mineral,  not  properly  an  ore, 
called : 

Emerald-nickel,  a  carbonate  of  nickel,  contain- 
ing 28.6  water  when  pure.  It  forms  incrustations 
on  other  minerals,  like  another  called 

Millebite,  a  sulphide  of  nickel  forming  tufts  of 
very  fine  acicular,  brassy-looking  crystals,  in  cavities 
of  the  red  hematite  of  Sterling  Iron  Mines  in  North- 
ern New  York,  and  velvety  incrustations  on  ores 
in  Lancaster  Co.,  Penna.,  where  nickel  was  found  and 
worked.  In  the  former  place  no  nickel  abounds, 
but  in  the  latter  it  has  in  the  past  been  found  in 
paying  quantities.  But  the  sulphides  forms  at  the 
latter  place  vary  very  much,  as  examined  under  the 
microscope,  from  the  acicular  crystals  found  in  the 
ores  at  Sterling,  N.  Y.,  and  yet  they  are  of  the  same 
chemical  combination.  The  ore  upon  which  the 
tufts  of  velvety  covering  are  found  at  the  Gap  Mine, 
Lancaster  Co.,  Penn.,  is  pyrrhotite  or  sulphide  of 
iron,  holding  4  to  5.9  per  cent,  nickel  in  composi- 
tion ;  that  of  Sterling,  N.  Y.,  is  the  red  hematite. 


The  sources  of  nickel  discovered  in  Sudbury, 
Canada,  north  of  Georgian  Bay,  yield  nickel  in 
pyrrhotite  (sulphide  of  iron),  and  apparently  also  in 
chalcopyrite,  whose  typical  composition  is  copper 
34.6,  iron  30.5,  sulphur  34.9.  It  is  a  mineral  of 
brass-yellow  appearance,  and  one  which  furnishes 
the  copper  of  commerce  at  the  Cornwall  Mines 
(Eng.)  and  at  the  copper  beds  in  Fahlun,  Sweden. 
In  the  latter  place  it  is  imbedded,  as  it  appears  to 
be  in  the  region  of  the  Sudbury  Mines,  only  that 
the  Sudbury  ore  is  imbedded  in  pyrrhotite  and  the 
Swedish  in  gneiss. 

The  chalcopyrite  does  not  mix  intimately  with 
the  nickel  ore  so  as  to  form  a  homogeneous  mass ; 
it  occurs  by  itself  in  pockets  or  threads,  etc.,  but 
inclosed  with  massive  pyrrhotite,  which,  while  it 
may  have  more  than  30  per  cent,  of  nickel  present, 
does  not  show  any  sign  of  the  changed  composition.* 

This  per  cent,  is  far  above  the  average  of  nickel 
in  the  pyrrhotite,  which  seldom  carries  less  than  2J 
per  cent,  or  more  than  9  per  cent,  of  nickel. 

The  following  new  ores  of  nickel  are  reported  by 
Dr.  Emmons  from  Sudbury,  Canada : 

Foleyrite,  of  a  bronze-yellow  color,  grayish-black 
streak,  and  metallic  lustre.  It  occurs  massive  and 
contains  32.87  per  cent,  of  nickel.  Its  specific 
gravity  is  4.73,  hardness  3.5. 

Whartonite  contains  6.10  per  cent,  of  nickel.  It 
has  a  pale  bronze-yellow  color,  black  streak  and 

*  Dr.  E.  B.  Peters,  Manager  of  the  Canada  Copper  Company. 


MERCURY,  BISMUTH,  NICKEL,  ETC.  209 

metallic  lustre.     Specific  gravity  about  3.73  ;  hard- 
ness about  4. 

Jack's  Tin  or  Blueite  contains  3.5  per  cent,  of 
nickel.  It  is  of  an  olive-gray  to  bronze  color,  me- 
tallic lustre  and  black  streak.  Specific  gravity  4.2; 
hardness  3  to  3.5. 

ANALYSIS  OF  ORES  FOR  NICKEL  AND  COBALT. 

As  this  analysis  requires  care,  we  give  the  follow- 
ing method  in  full : 

1.  Keduce  finely  50  grains  of  the  ore.  Put  it  in 
a  dry  beaker-glass  and  pour  over  it  a  mixture  of  one 
part  sulphuric  acid  with  three  parts  nitric  acid,  both 
pure  and  concentrated,  or  40  to  50  c.c.  to  2  grams 
of  ore. 

2.  Heat  the  covered  beaker  on  a  sand-bath  to 
near  212°  Fah.  for  two  hours.  Then  partly  un- 
cover, and  evaporate  the  nitric  acid  entirely. 

3.  Cool  and  add  100  or  more  c.c.  of  water  and 
let  it  stand  for  four  hours  ;  the  insoluble  residue  is 
lead  sulphate,  silex,  etc. 

4.  Filter  off  the  soluble  part  and  place  the  moist 
lead  sulphate  in  a  beaker  and  dissolve  it  by  first 
pouring  in  ammonia  (20-25  c.c),  and  next  acetic 
acid  till  it  is  decidedly  acid.  The  sulphate  now 
dissolves  if  kept  warm  for  some  twenty  minutes. 
Filter  and  wash,  and  if  any  residue  remains  (silex, 
etc.),  reserve  for  future  examination. 

5.  The  lead  'is  now  separate,  but  if  the  amount 
is  sought,  pass  a  current  of  hydrogen  sulphide 
through  the  solution   till  the  lead  is  entirely  pre- 

14 


210      prospector's  field-book  and  guide. 

cipitated.  Filter,  dry,  place  the  residue  in  a  porce- 
lain crucible  and  heat  to  a  low-red  heat,  passing  a 
current  of  dry  hydrogen  into  the  crucible  while 
heating,  to  prevent  any  oxidizing  of  the  sulphide. 
When  the  crucible  and  contents  remain  the  same 
in  weight,  the  last  weight  of  the  lead  sulphide  is  the 
correct  amount.  Of  this  weight,  86.61  parts  in  100 
are  lead,  13.39  are  sulphur. 

If  the  ore  has  no  lead  in  it,  the  above  work  is 
omitted  entirely.  The  likelihood  of  lead  may  be 
tested  qualitatively  from  a  small  quantity  dissolved, 
precipitated  by  hydrogen  sulphide,  and  the  precipi- 
tate determined  by  the  blow-pipe  on  charcoal  giving 
the  lead  coating,  and  with  soda,  the  metallic  globule. 

6.  To  separate  the  copper.  The  filtrate  re- 
maining after  the  insoluble  lead  sulphate  was  fil- 
tered ofT,  as  in  No.  4,  now  contains  whatever  the 
mineral  is  composed  of,  copper,  iron,  nickel,  cobalt, 
etc.  Dilute  the  filtrate  to  about  500  c.c,  heat  to 
nearly  boiling,  and  pass  hydrogen  sulphide  through 
it,  and  thus  precipitate  all  the  copper  after  adding 
1  or  2  c.c.  of  hydrochloric  acid.  Filter,  wash,  dry, 
and  ignite  the  precipitate  in  an  atmosphere  of 
hydrogen.  The  result  will  be  pure  Cu2S,  from 
which  the  copper  may  be  ascertained  as  79.85  parts 
of  the  whole  weight  of  Cu2S. 

7.  Concentrate  by  evaporation  the  filtrate  of 
No.  6  remaining  after  the  copper  was  separated,  add 
1  or  2  c.c.  of  nitric  acid,  and  boil  the  filtrate  two 
or  three  minutes,  let  it  become  nearly  cold,  add  an 
excess  of  ammonia,  and  let  it  stand  in  a  warm  place 
half  an  hour. 


MERCURY,  BISMUTH,  NICKEL,  ETC.  211 

8.  Filter  the  precipitate  into  a  porcelain  dish  and 
redissolve  the  iron  oxide  (hydroxide)  with  hydro- 
chloric acid  poured  slowly  into  the  filter,  complete 
washing  of  the  filter  with  hot  water,  reduce  the  free 
acid  in  the  filtrate  with  ammonia,  then  very  nearly 
neutralize  it  carefully  with  sodium  (metallic)  or 
ammonium  carbonate ;  the  solution  must  remain 
clear,  though  dark  red,  if  much  iron  is  present. 
Now  add  a  strong  neutral  solution  of  ammonium  or 
sodium  acetate  (not  in  large  excess),  and  then  boil 
a  short  time.  When  rightly  performed  the  iron 
oxide  precipitate  will  settle  rapidly,  and  the  super- 
natant liquor  will  be  clear.  Wash  rapidly  with 
boiling  water,  and,  at  first,  separate  the  clear  part 
by  decantation,  and  then  filter.  If  great  exactitude 
is  required,  redissolve  in  hydrochloric  acid,  and 
once  more  precipitate  with  the  acetate  just  as  before. 
Add  this  filtrate  to  the  ammoniacal  filtrate  men- 
tioned at  the  beginning  of  No.  7  paragraph. 

The  iron  is  now  separated  as  basic  ferric  acetate, 
and  it  is  almost,  if  not  entirely,  separated  from  all 
nickel  and  cobalt  which  are  yet  in  solution. 

9.  The  first  filtrate,  No.  7,  contains  all  the  nickel 
and  cobalt.  It  must  now  be  concentrated  to  about 
250  c.c.  If  it  is  slightly  acid,  proceed  ;  if  not,  then 
add  muriatic  acid  until  it  is  very  slightly  acid. 
Now  heat  the  filtrate  in  a  beaker  to  gentle  boiling, 
and  pass  hydrogen  sulphide  through  the  liquid.  A 
black  precipitate  follows  ;  if  nickel  sulphide  with 
cobalt  sulphide,  they  are  together. 

10.  Filter,  wash,  and  dry  ;    incinerate  the  filter- 


212      prospector's  field-book  and  guide. 

paper  with  the  precipitate  if  very  small  in  quantity, 
otherwise  separately ;  heat  in  porcelain  crucible. 
Dissolve  in  aqua  regia  (nitro-muriatic  acid),  and 
treat  it  till  only  yellow  sulphur  remains,  evaporate 
and  expose  the  residue  to  a  heat  of  180°  Fah.  to 
make  any  silica  insoluble.  Moisten  with  a  few 
drops  of  muriatic  acid,  add  20  c.c.  of  water  to  dis- 
solve the  salts,  add  some  solution  of  hydrogen  sul- 
phide to  separate  any  copper  or  lead  which  may 
have  escaped  separation,  filter  into  a  porcelain  dish 
and  concentrate  all  to  about  100  c.c. 

11.  Boil  gently,  and  while  boiling  add  pure  so- 
dium carbonate  solution  until  the  liquid  is  slightly 
alkaline.  Continue  boiling  a  few  minutes,  add  a 
few  grains  of  pure  soda  solution  (sodium  hydroxide). 
This  is  best  prepared  freshly  by  dropping  a  small 
ball  of  metallic  sodium  into  a  half  ounce  of  water 
in  a  platinum  dish  or  crucible,  or,  not  so  well,  in  a 
porcelain  dish.  Heat  to  a  boiling  again  a  few  min- 
utes till  all  the  nickel  and  cobalt  are  precipitated, 
wash  the  precipitate  with  boiling  hot  water  by  de- 
cantation,  and  finally  on  the  filter,  until  a  drop  on 
polished  platinum  shows  no  residue.  After  drying 
the  precipitate  remove  it  to  a  piece  of  glazed  paper ; 
cover  with  a  bell-glass.  Then  incinerate  the  filter 
till  the  carbon  has  entirely  disappeared,  add  it  to 
the  precipitate  already  obtained,  place  all  in  a  cru- 
cible, cover  it  and  expose  to  heat  to  redness,  and, 
finally,  if  desired,  reduce  the  oxides  to  the  metallic 
condition  by  ignition  under  a  stream  of  hydrogen. 

12.  As  this  process  of  reduction  to  metal  is  some- 


MERCURY,  BISMUTH,  NICKEL,  ETC. 


213 


times  very  useful,  we  give  a  sample  plan  of  appa- 
ratus for  this  purpose.  Get  a  half-pint  wide- 
mouthed  pickle  bottle  and  introduce  two  glass  tubes 
of  a  quarter-inch  diameter  into  a  cork  fitting  the 
mouth,  after  having  nicely  adjusted  the  cork  to  the 
mouth  of  the  bottle.  The  tubes  may  be  easily  bent 
and  blown  as  in  A  B,  Fig.  60,  over  the  flame 
of  an  alcohol  lamp,  before  permanently  fastening 
them  in  place.      To  blow  a  funnel  end,  heat  the  end 

Fig.  60. 


of  the  tube  to  softness  and  mash  it  together,  her- 
metically seal,  then  reheat  rapidly,  roll  it  between 
finger  and  thumb  while  gently  blowing  at  the  other 
end  until  swollen  large  enough,  then,  with  pincers, 
break  it  or  chip  it  off ;  if  enlarged  twice  or  three 
times  the  diameter,  it  is  large  enough  for  the  pur- 
pose. The  tubes  intended  to  be  bent  should  be 
rapidly  rotated  in  the  enlarged  flame  until  red-hot, 
and  then  bent  to  the  right  angle  and  gradually 
cooled. 


214 

It  is  well  to  make  another  of  these  bottles  for  dry- 
ing the  hydrogen,  as  in  B.  Introduce  the  tube  as 
shown  in  the  figure,  wherein  B  represents  the  drying 
bottle  in  which  is  placed  a  quantity  of  fragments 
of  chloride  of  calcium  of  the  size  of  peas  or  even 
smaller.  In  putting  the  cork  with  tubes  into  this 
bottle,  the  bottle  should  be  on  its  side  and  rolled 
while  introducing  the  longer  tube  into  the  calcium 
chloride,  so  that  the  fragments  may  not  obstruct 
the  tube  as  it  is  pushed  down.  The  exit  tube  may 
be  bent  or  straight,  and  properly-sized  india-rubber 
tubing  may  be  fitted  over  the  ends  so  as  to  make 
connections.  A  common  clay  stem  smoking  pipe 
arranged  as  in  the  figure,  with  the  bowl  inverted 
into  the  crucible  which  is  placed  on  a  wire  support 
on  a  retort  stand,  c,  is  quite  sufficient.  The  usual 
alcohol  blast  lamp,  d,  is  necessary  for  this  operation. 
To  put  the  apparatus  to  work  it  is  only  necessary  to 
introduce  some  three  or  four  ounces  of  broken-up 
pieces  of  zinc  into  A,  together  with  water  sufficient 
to  half  fill  the  bottle,  cork  up  with  the  tubes  ar- 
ranged as  above,  and  pour  into  the  funnel-shaped 
tube  common  oil  of  vitriol  gradually,  until  the  gas 
begins  to  come  over,  then  stop  as  the  water  becomes 
heated,  and  the  gas  will  increase  without  addition. 
You  may  now  prepare  your  crucible,  and,  when  in 
place,  and  the  tubes  all  arranged,  the  gas  may  be 
made  to  come  over  more  rapidly  by  adding  a  little 
more  oil  of  vitriol,  drop  by  drop. 

13.  The  crucible  should  be  weighed  after  cooling 
and  replaced,  the  flame  of  the  blast  lamp  relighted, 


MERCURY,  BISMUTH,  NICKEL,  ETC.  215 

and  red  heat  renewed  under  the  hydrogen  apparatus 
until  the  crucible,  when  again  weighed,  shows  no 
alteration  in  weight.  The  oxide  has  now  been  re- 
duced to  the  pure  metal  form,  and  it  may  then  be 
cooled. 

In  the  case  of  the  analysis  we  are  now  upon,  the 
metallic  reduction  will  be  that  of  both  nickel  and 
cobalt,  and  they  will  appear  as  a  dark  powder  in 
the  bottom  of  the  crucible. 

When  the  hydrogen  apparatus  is  no  longer  to  be 
used,  the  generator  bottle  A  should  be  washed  thor- 
oughly and  the  zinc  also  ;  the  latter  may  be  left  in 
the  bottle  and  the  cork  replaced  loosely,  but  the 
cork  must  be  removed  from  bottle  B,  and  a  tight- 
fitting  cork  be  used  in  its  place,  as  the  chloride  may 
be  used  again.  All  is  ready  for  another  operation 
by  simply  replacing  and  adding  water  and  acid  as 
before. 

14.  Separation  op  Nickel  and  Cobalt.  The 
two  metals  should  be  weighed  in  order  that,  if  the 
cobalt  be  found,  the  nickel  may  be  known  by  the 
difference.  Dissolve  the  two  metals  in  nitric  acid 
and  evaporate  them  till  there  is  no  free  nitric  acid. 
Next  add  about  6  to  8  grams  (100  grains)  potas- 
sium nitrate  dissolved  in  10  to  15  c.c.  of  hot  water. 
If  any  flocculent  particles  appear,  add  a  little 
acetic  acid,  just  sufficient  to  dissolve  them,  and 
now  a  precipitate  of  cobalt  (as  tripotassium  cobaltic 
nitrate),  takes  place  slowly.  The  whole  volume 
should  now  be  15  to  20  c.c.  Cover  the  beaker  con- 
taining it  with  glass,  and  set  it  aside  in  a  warm 


216      prospector's  field-book  and  guide. 

place  for  twenty-four  hours.  Filter,  wash  with  a 
solution  of  potassium  acetate  (which  may  be  made 
by  neutralizing  acetic  acid  with  crystallized  potas- 
sium bicarbonate,  leaving  the  solution  slightly 
acid),  and  proceed  to  more  efficiently  separate  the 
cobalt  as  a  metal,  as  follows : 

Dilute  the  filtrate,  heat,  and  precipitate  with 
caustic  soda  (sodium  hydroxide),  wash  the  greater 
part  of  the  saline  matter  out  and  then  dissolve  the 
precipitate  in  nitric  acid,  evaporate  to  dryness,  add 
two  or  three  drops  of  nitric  acid  and  dissolve  in  a 
small  volume  of  water,  filter,  concentrate  the  fil- 
trate, and  repeat  the  process  of  separation  of  potas- 
sium nitrate  as  before.  Put  this  precipitate,  with 
the  filter-paper,  into  a  beaker,  add  about  100  c.c.  of 
water,  heat,  add  muriatic  acid  to  dissolve  it,  separate 
the  filter-paper  by  filtering  it  and  washing  it  in  a 
funnel,  evaporate  the  solution  on  a  water-bath,  and 
let  it  remain  on  the  water-bath  two  or  three  hours 
to  render  the  silica  insoluble,  then  moisten  with 
muriatic  acid,  add  water,  filter,  and  convert  the  co- 
balt to  metallic  form,  as  was  done  before  for  both 
nickel  and  cobalt,  namely,  as  in  paragraph  No.  11. 
The  cobalt  is  now  entirely  separate  from  the  nickel. 
Weigh  it,  and  by  difference  from  the  weight  of  the 
two  determine  the  weight  of  nickel  as  suggested  in 
No.  14.  The  amount  of  nickel  is  now  known  by 
weight,  and  readily  compared  with  the  whole 
amount  of  the  original  weight  of  ore  employed  at 
the  beginning. 

If  the  above  process  is  carefully  followed  out,  in  a 


MERCURY,  BISMUTH,  NICKEL,  ETC.  217 

mineral  containing  lead,  copper,  iron,  cobalt,  and 
nickel,  the  cobalt  and  nickel  are  separated  with 
great  exactness. 

But  the  main  ore  of  nickel  is  pyrrhotite,  and,  as 
in  the  Gap  Mine,  Lancaster  Co.,  Penn.,  and  in  the 
Sudbury  Mines,  Canada,  pyrrhotite  contains  only 
iron  and  nickel,  seldom  cobalt  enough  to  notice. 
So  that  much  less  work  is  required,  as  follows  :  Pul- 
verize, dissolve  in  muriatic  acid  in  a  flask.  If 
much  free  acid  is  present,  nearly  neutralize  with 
sodium  or  ammonium  carbonate;  the  solution  should 
be  clear,  but,  if  there  is  much  ferric  chloride,  it 
should  be  of  a  deep-red  color  ;  now  do  as  directed  in 
No.  8,  to  add  the  ammonium  acetate,  and  proceed 
as  before. 

In  view  of  the  importance  of  nickel-steel  armor 
plates,  prospecting  for  nickel  is  a  work  of  unusual 
interest.  In  addition  to  the  discovery  of  the  nickel 
pyrrhotite  in  Canada,  which  we  have  already  no- 
ticed, new  discoveries  have  been  reported  from  New 
Caledonia,  an  island  900  miles  east  of  Australia. 
The  ore  is  a  nickel  silicate  and  has  been  named 
Garnierite,  after  M.  Gamier,  its  discoverer.  It  is 
also  found  in  Oregon.  It  contains  from  8  to  10  per 
cent,  of  nickel,  has  a  green  color  and  yields  an  un- 
colored  streak. 

The  mines  at  the  Gap,  Lancaster  Co.,  Penn.,  are 
considered  nearly,  if  not  quite,  exhausted.  There  is 
now,  as  may  readily  be  imagined,  increased  demand 
for  nickel  ores. 

IV.  Cobalt. — Cobalt  does  not   occur  in  native 


218      prospector's  field-book  and  guide. 

form.  The  following  are  the  minerals  of  impor- 
tance : 

Smaltite  seems  to  be  composed  of  cobalt,  nickel, 
iron  and  arsenic;  the  typical  form  is  arsenic  72.1, 
cobalt  9.4,  nickel  9.5,  iron  9  =  100.  Hardness 
5.5-6 ;  specific  gravity  6.4-7.2.  Color,  tin-white, 
sometimes  iridescent.  Streak,  grayish-black.  Brit- 
tle. Before  the  blow-pipe,  on  charcoal  with  soda,  the 
arsenious  acid  fumes  are  given  off,  and  the  garlic 
smell  is  plainly  observed.  With  borax  for  the  bead 
the  assay  may  be  made  to  show  (with  successive 
heatings)  the  reactions,  first  of  iron,  then  cobalt,  and 
nickel,  provided  the  operator  is  skillful  in  oxidizing 
the  powdered  ore  by  cautious  degrees ;  when  one 
borax  bead  shows  iron  reaction  by  a  certain  amount 
of  carefully  applied  0  F  to  the  bead,  try  another 
wTith  increased  degree  of  oxidation  until  you  per- 
ceive the  cobalt  blue  and  nickel  brown,  if  both  are 
present. 

Cobaltite  is  composed  of  sulphur,  arsenic,  and 
cobalt  in  the  typical  proportions  of  19.3,  45.2,  35.5 
=  100,  but  it  frequently,  as  a  mineral,  contains  iron. 
Hardness  5.5  ;  specific  gravity  6-6.3.  Under  the 
blow-pipe,  in  an  open  tube,  it  sends  off  sulphurous 
fumes  and  a  sublimate  of  arsenious  acid.  With  borax 
bead  gives  the  blue  of  cobalt.  Dissolves  in  warm 
nitric  acid,  separating  the  sulphur  and  arsenic. 

Cobaltite  and  smaltite  are  valuable  as  affording 
the  greater  part  of  smalt  of  commerce,  and  the  for- 
mer is  used  in  porcelain  painting. 

Erythrite  is  a  soft  (1.5-2.5)  peach-red  mineral 


MERCURY,  BISMUTH,  NICKEL,  ETC.  219 

of  specific  gravity  2.9,  transparent  or  translucent, 
sometimes  pearl-  or  greenish-gray. 

Composition,  typical,  arsenic  38.43,  cobalt  oxide 
37.55,  water  24.02  =  100. 

In  a  closed  tube,  under  blow-pipe,  it  yields  water 
and  turns  bluish.  Gives  the  usual  blue  for  cobalt 
in  the  borax  bead. 

Valuable  for  the  manufacture  of  smalt.  It  is 
sometimes  knowm  as  " cobalt  bloom" 

Linn^eite.  This  is  valuable  for  the  large  amount 
of  both  cobalt  and  nickel  it  sometimes  contains. 
Hardness  5.5  ;  specific  gravity  4.8-5;  metallic  lustre ; 
color,  pale  steel-gray,  tarnishing  to  red.  Composi- 
tion, sulphur  42,  cobalt  58  ==  100,  but  cobalt  is  re- 
placed by  large  amounts  of  nickel,  and  sometimes 
copper.  Some  specimens  from  Mineral  Hill,  Mary- 
land, and  from  Missouri,  have  yielded  as  high  as 
29.56  and  30  per  cent,  nickel,  with  21  to  25  per 
cent,  cobalt  in  the  same  specimen,  but  with  a  small 
amount  of  iron  (3  per  cent.). 

Earthy  Cobalt,  or  Cobalt  Wad  (Asbolite  is  the 
mineralogical  name),  occurs  as  a  bog  ore,  with  man- 
ganese, iron  and  copper,  and  nickel.  It  is  blue 
black  at  times,  has  a  hardness  of  1  to  1.5,  and 
specific  gravity  of  2.2  to  2.6.  It  sometimes  contains 
up  to  35  per  cent,  of  cobalt  oxide. 

The  geological  position  of  cobalt  is  in  the  earlier 
rocks,  as  the  chlorite  slates  with  chalcopyrite,  blende, 
and  pyrite,  as  in  Maryland.  Sometimes  the  ore  is 
found  in  cavities  in  the  limestone  of  the  carbonifer- 
ous age,  as  in  Great  Britain.     The  tin-white  cobalt 


is  found  in  the  gneissic  and  primitive  rocks,  as  in 
Norway.  Linnaeite  is  found  at  Mine  la  Motte,  Mo., 
in  masses,  sometimes  in  octahedral  crystals  among 
its  rich  ores  of  lead  and  nickel. 

Cadmium.  Of  this  mineral  but  one  ore  is  known, 
namely,  the  sulphide,  or  Greenockite,  with  77.7 
per  cent,  cadmium.  Color,  honey  to  orange-yellow 
and  brick-red  ;  in  hexagonal  prisms  ;  hardness  3  to 
3.5  ;  specific  gravity  4.5  to  4.908.  Before  the  blow- 
pipe, on  charcoal  with  soda,  it  yields  a  red-brown 
deposit.  Cadmium  is  frequently  associated  with 
zinc  ores,  some  varieties  of  sphalerite  or  blende  con- 
taining 3.4  per  cent. 

Metallic  cadmium  is  white  like  tin,  and  shares 
with  it  the  property  of  emitting  a  crackling  sound 
when  bent.  It  is  so  soft  that  it  leaves  a  mark  upon 
paper. 


CHAPTER  XII. 

ALUMINIUM,  ANTIMONY,  MANGANESE. 

I.  Aluminium.  The  distribution  of  aluminium 
in  nature  is  very  wide,  rivaliug  that  of  iron,  yet  there 
are  but  few  minerals  which  serve  as  sources  of  the 
metal.  These  are  :  Bauxite,  a  limonite,  in  which 
most  of  the  iron  is  replaced  by  aluminium  ;  soft  and 
granular,  with  50  to  75  per  cent,  alumina.  Corun- 
dum, crystalline  and  very  hard,  specific  gravity  4, 
generally  quite  pure,  but  too  valuable  for  abrasive 
purposes  to  be  used  as  an  ore.  Diaspore,  hard  and 
crystalline,  specific  gravity  3.4,  with  64  to  85  per 
cent,  alumina,  and  ordinarily  quite  pure.  Gibbsite, 
stalactic,  specific  gravity  2.4,  containing,  when  pure, 
65  per  cent,  alumina.  Aluminite,  specific  gravity 
1.66,  a  sulphate  of  aluminium  found  in  large  beds, 
chiefly  along  the  Gila  River,  in  New  Mexico,  con- 
taining about  30  per  cent,  alumina,  and  easily  solu- 
ble in  water.  Cryolite,  specific  gravity  2.9,  easily 
fusible,  and  when  fused  its  specific  gravity  is  about 
2.  It  contains  40  per  cent,  aluminium  fluoride  and 
60  per  cent,  sodium  fluoride.  All  clays  contain  a 
large  percentage  of  aluminium,  but  always  in  the 
state  of  silicate,  and  the  difficulty  of  removing  this 
silica  has  so  far  prevented  the  employment  of  clay 
as  an  ore  of  aluminium. 

(221) 


222      prospector's  field-book  and  guide. 

Of  the  ores  above  named  the  most  important  is 

Bauxite,  of  which  there  are  vast  deposits  at 
Baux,  near  Aries,  in  France,  in  Ireland,  and  in 
Alabama,  Arkansas,  the  Carolinas,  Georgia,  Tennes- 
see and  Virginia. 

The  Arkansas  deposits  are  said  to  cover  a  large 
area,  and  to  reach  a  thickness  of  40  feet,  forming 
an  interbedded  mass  in  ferruginous  Tertiary  sand- 
stone. 

The  Alabama  deposits  are  better  known,  and  all 
occur  in  the  lower  part  of  the  lower  Silurian  forma- 
tion. The  district  has  been  badly  broken  up  by 
sharp  fold  and  great  thrust  faults,  and  the  mineral 
occurs  as  pockets  in  close  association  with  brown 
iron  ore  (limonite)  and  clay. 

Bauxite  has  to  undergo  purification  for  the  pur- 
pose of  the  aluminium  manufacturer.  Several 
methods  are  used  : 

1.  It  is  chosen  as  free  from  iron  as  possible,  and 
is  roasted  at  a  low  red  heat,  and  afterwards  treated 
with  sulphuric  acid,  which  combines  with  the 
alumina  present,  forming  sulphate  of  alumina. 
This  is  readily  dissolved  by  water,  leaving  the  great 
bulk  of  silica  and  iron  behind.  The  solution  of 
sulphate  of  alumina  is  allowed  to  settle,  the  super- 
natant liquid  is  siphoned  off  into  an  evaporating 
tank  and  evaporated  to  dryness.  The  dry  sulphate 
of  alumina  is  calcined  at  a  red  heat,  driving  off  the 
sulphuric  acid,  leaving  as  a  residue  anhydrous 
alumina. 

2.  The  bauxite  is  treated  either  by  fusing  with 


ALUMINIUM,  ANTIMONY,  MANGANESE.  223 

carbonate  of  soda  and  dissolving  in  water,  or  by 
boiling  it  with  a  strong  solution  of  caustic  soda. 
In  either  case  a  solution  of  sodium  aluminate  is  ob- 
tained, which  is  filtered  from  the  residue  of  silica 
and  ferric  oxide,  and  decomposed  into  aluminium 
hydrate  and  carbonate  of  soda  by  pumping  carbonic 
acid  gas  through  it.  After  a  thorough  washing,  the 
hydrate  is  calcined  at  a  high  heat,  and  the  resulting 
alumina  is  finely  ground. 

The  ore  next  in  importance  is 

Cryolite,  of  which  there  is  practically  only  one 
productive  mine,  that  at  Ivigtut,  South  Greenland. 
The  mine  is  worked  as  a  quarry,  and  has  been 
opened  450  feet  long,  150  feet  wide  and  100  feet 
deep,  while  diamond  drills  have  proved  the  perma- 
nence of  the  ore  for  a  further  depth  of  150  feet.  The 
vein  appears  to  widen  with  depth,  but  the  quality 
of  the  mineral  becomes  inferior.  About  10,000 
tons  of  cryolite  annually  are  shipped  to  the  United 
States. 

With  the  blow-pipe,  on  charcoal,  cryolite  fuses  to  a 
clear  bead,  becoming  opaque  on  cooling.  After  long 
blowing  with  O  F  the  assay  spreads  out,  the  fluoride 
of  sodium  sinks  into  the  charcoal,  and  the  suf- 
focating odor  of  fluorine  is  given  off  and  the  alumin- 
ium remains  as  a  crust  which,  if  touched  with  a 
little  cobalt  solution  and  gently  heated,  gives  a  blue 
color  of  alumina.  If  some  of  the  cryolite  is  pow- 
dered and  placed  near  the  open  end  of  a  glass  tube 
and  the  flame  from  the  blow-pipe  turned  carefully 
on  it,  the  fluorine  will  be  freed  and  will  etch  the 


224 

glass,  showing  corrosion  and  proving  the  presence 
of  fluorine.  Besides,  as  a  source  of  the  metal  alu- 
minium, cryolite  is  used  as  a  flux,  and  largely  for 
the  manufacture  of  alumina  of  soda. 

While  the  older  processes  of  aluminium  manu- 
facture, dependent  on  the  reduction  of  the  double 
chloride  of  aluminium  and  sodium,  must  always 
have  a  scientific  interest,  they  have  been  beaten  out 
of  the  field  of  commercial  industry  by  the  newer 
electrolytic  methods,  of  which  there  are  four  varie- 
ties. In  England  and  America  Cowles'  and  Hall's 
patent  are  followed ;  on  the  Continent,  Heroult's 
and  Minet's.  They  are  all  virtually  modifications 
of  the  original  Deville-Bunsen  process,  maintaining 
fusion  by  the  heat  of  the  electric  current. 

Corundum  and  Emery.  While  corundum  and 
emery  are  very  nearly  allied  mineralogically,  they 
are  sharply  distinguished  in  commerce.  Corundum 
is  almost  a  pure  alumina,  but  emery  is  contaminated 
with  a  large  proportion  of  iron  oxide,  ranging  gen- 
erally between  20  and  33  per  cent.  Physically  they 
are  also  distinguished  by  the  following  features : 
Corundum  is  variously  colored,  commonly  gray,  but 
never  black.  It  is  much  harder  than  emery,  with 
sharper  edges,  and  cuts  more  deeply  and  rapidly. 
It  is,  however,  more  brittle,  aud  therefore  less  dur- 
able.    Emery -is  practically  always  black. 

Corundum  is  infusible  before  the  blow-pipe,  and 
is  not  affected  by  acids  nor  by  heat.  It  crystallizes 
in  six-sided  prisms,  often  irregularly  shaped  and 
sometimes  occurs  in  granular  masses.     Transparent 


ALUMINIUM,  ANTIMONY,  MANGANESE.  225 

or  opaque.  Lustre,  glassy,  sometimes  pearly. 
Fracture  uneven  or  conchoidal.  Specific  gravity, 
3.9  to  4.2.  Hardness,  9,  it  being,  next  to  diamond, 
the  hardest  of  minerals.  It  is  generally  found 
associated  with  some  member  of  the  chlorite  group, 
and  a  series  of  aluminous  minerals  in  part  pro- 
duced from  its  alteration. 

The  blue  variety  of  corundum  is  called  Sapphire, 
the  most  esteemed  shade  being  deep  velvet  blue ; 
the  blood-red  variety  is  the  Oriental  Ruby,  which 
can  be  readily  distinguished  from  other  red  gems 
by  its  superior  hardness ;  the  bright  yellow  variety 
is  the  Oriental  Topaz,  distinguished  by  its  hard- 
ness from  the  topaz,  yellow  tourmaline  and  false 
topaz  ;  the  bright  green  is  the  Oriental  Emerald  ; 
the  bright  violet,  Oriental  Amethyst.  One  vari- 
ety exhibits  a  six-rayed  star  inside  the  prism,  and 
is  called  the  Asterias.  Euby  is  the  most  highly 
prized  form  of  this  mineral. 

Corundum  has  been  found  in  a  large  number  of 
localities  in  the  United  States,  but  only  a  few  places 
have  been  actual  producers.  The  emery  vein  or 
bed  at  Chester,  Mass.,  has  furnished  a  large  quan- 
tity of  the  mineral,  but  the  chief  American  source 
at  present  is  a  belt  of  serpentine  that  extends  from 
southwestern  North  Carolina  into  Georgia.  It  is  an 
altered  olivine  rock,  and  has  gneiss  for  its  immedi- 
ate associate,  and  along  the  contact  of  the  two  are 
found  the  veins  or  beds  of  decomposed  rock  which 
have  the  corundum  disseminated  through  them. 
Corundum  Hill,  in  North  Carolina,  and  Laurel 
15 


226      prospector's  field-book  and  guide. 

Creek,  in  Georgia,  are  the  chief  producers.  The 
mineral  is  crushed,  sifted  and  washed,  and  thus 
comes  to  market  in  various  sizes.  Care  is  taken  to 
avoid  making  undue  amounts  of  the  finest  product, 
or  "  flour,"  for  this  has  less  value  than  the  coarser 
grades. 

The  chief  European  sources  of  emery  are  the 
Greek  island  of  Naxos  and  Asiatic  Turkey. 

The  usual  test  for  the  quality  of  a  sample  of 
emery  or  corundum  is  to  compare  a  weighed  sample 
with  an  equal  amount  of  the  standard  grade  or  of 
some  well-recognized  brand.  Two  weighed  pieces 
of  plate  glass  of  convenient  size  are  then  rubbed  to- 
gether with  the  sample  between,  and  the  process  is 
continued  until  the  grit  has  disappeared  and  the 
plates  no  longer  lose  in  weight  from  the  abrasion. 
The  amount  of  loss  is  a  measure  of  the  hardness 
and  abrading  power  of  the  sample,  the  better  grade 
giving  the  greater  loss. 

III.  ANTIMONY.  This  metal  occurs  in  three 
forms,  namely,  the  oxide,  senarmontite,  containing 
83.56  per  cent,  antimony ;  the  sulphide,  stibnite, 
antimonite  or  antimony  glance,  affording  71.8  per 
cent.,  a  sulphoxide,  kermesite,  giving  75.72  per  cent., 
in  addition  to  some  unimportant  combinations  with 
silver,  etc.  While  it  may  be  said  that  antimony  is 
somewhat  widely  distributed  in  nature,  yet,  owing 
to  cost  and  difficulties  in  extraction,  only  compara- 
tively few  mines  affording  a  rich  ore  can  be  profit- 
ably worked.  Beyond  the  considerable  quantities 
of  oxide  coming  from  Algiers  and  of  kermesite  from 


ALUMINIUM,  ANTIMONY,  MANGANESE.  227 

Tuscany,  almost  the  entire  output  is  in  the  form  of 

Stibnite,  which  contains  78.8  per  cent,  antimony 
and  28.2  sulphur.  Hardness,  2  ;  specific  gravity, 
4.5.  Streak  and  color,  lead  grey  inclining  to  steel 
grey,  subject  to  blackish  tarnish,  sometimes  irides- 
cent. Lustre,  metallic ;  sectile.  Occurs  in  rhom- 
bic, generally  in  radiated  or  divergent  bunches ; 
massive  with  columnar  or  fibrous  structure.  Sol- 
uble in  hydrochloric  acid  giving  a  slight  crystalline 
precipitate  of  lead  chloride  if  lead  be  present. 

Before  the  blow-pipe,  on  charcoal,  it  fuses,  spreads 
out,  gives  sulphurous  and  antimonious  fumes,  coats 
the  charcoal  with  white  oxide  of  antimony  ;  this 
coat,  treated  in  R  F,  tinges  the  flame  greenish  blue. 

Foremost  in  antimony  production  stands  Portu- 
gal, due  principally  to  the  mining  district  of  Oporto. 
The  geological  formations  of  Portugal  are  chiefly 
igneous  and  old  sedimentary.  The  most  favorable 
rocks  for  good  antimony  ore  are  bluish  gray  argil- 
laceous Silurian  shales. 

Among  the  other  European  centers  of  production, 
the  Bohemian  mines  are  in  granite  and  mica  schist ; 
the  Hungarian  in  granite — sometimes  auriferous ; 
the  Styrian  in  dolomite,  and  the  Turkish  also  in 
granite.  Victoria,  New  South  Wales,  and  Western 
Australia  are  large  producers  of  auriferous  stibnite. 
In  New  Brunswick,  antimony  is  mined  in  a  quartz 
and  calcite  gangue  in  clay-slates  and  sandstones  of 
Cambro-Silurian  age. 

Within  the  United  States  stibnite  has  been  found 
in  a  number  of  places,  all  in  the  West.     At  San 


228      prospector's  field-book  and  guide. 

Emigdio,  Kern  Co.,  California,  it  is  contained,  with 
quartz  gangue,  in  a  vein  in  granite.  The  vein 
varies  in  thickness  from  a  few  inches  to  several  feet. 
Several  other  small  deposits  occur  in  San  Benito 
Co.  and  elsewhere  in  California.  Stibnite  has  also 
been  discovered  in  Humboldt  Co.,  Nevada,  and  in 
Louder  Co.,  not  far  from  Austin,  in  a  quartz  gangue. 
Some  remarkable  deposits  occur  in  Iron  County, 
Utah,  as  masses  of  radiating  needles,  which  follow 
the  stratification  planes  of  sandstone  and  fill  the 
interstices  of  a  conglomerate.  Stibnite  is  found  in 
Sevier  Co.,  Arkansas,  filling  veins,  with  a  quartz 
gangue,  in  sandstone. 

MANGANESE.  The  ores  of  manganese  are 
divided  into  three  general  classes  : 

1.  Manganese  ores. 

2.  Manganiferous  iron  ores. 

3.  Argentiferous  manganese  ores. 

Wad  is  the  name  given  to  manganese  oxide.  It 
is  found  in  earthy  compact  masses  of  a  dark  brown 
color,  chiefly  oxide  of  manganese  and  water. 

Easily  recognized  under  the  blow-pipe,  as  it  gives 
(in  minute  quantities),  in  the  borax  bead,  a  violet 
color  in  the  0  F,  but  disappears  when  the  R  F  is 
turned  upon  it,  and  reappears  when  the  0  F  is 
repeated. 

It  is  found  in  beds  varying  from  several  inches  to 
a  foot  or  more  in  thickness.  Hardness  1  to  3  ;  spe- 
cific gravity  2.3  to  3.7.  Wad  is  used  as  a  flux  in 
iron  smelting,  and  in  a  lixiviated  state  as  a  paint. 

Pyrolusite.     This  is  the  peroxide  or  dioxide, 


ALUMINIUM,  ANTIMONY,  MANGANESE.  229 

with  63.2  per  cent,  of  manganese  and  36.8  per  cent, 
oxygen.  Its  crystalline  form  is  the  rhombic  prism 
and  it  generally  occurs  in  the  form  of  minute  crys- 
tals grouped  together  and  radiating  from  a  common 
centre.  It  has  an  iron-black  or  steel-gray  color,  a 
semi-metallic  lustre  and  yields  a  black  streak. 
Specific  gravity  4.7  to  5  ;  hardness  1.5  to  2.5  ;  in- 
fusible before  the  blow-pipe,  and  acquires  a  red- 
brown  color.  On  heating  it  generally  yields  some 
water  and  loses  12  per  cent,  of  oxygen.  With 
borax,  soda  and  microcosmic  salt  it  shows  man- 
ganese reaction.  It  dissolves  in  hydrochloric  acid, 
when  heated,  with  vigorous  evolution  of  hydrogen. 

Psilomelane  occurs  massive,  frequently  shelly, 
seldom  fibrous;  color,  iron-black  to  bluish-black, 
streak  bluish-black  and  shining ;  fracture,  con- 
choidal  to  smooth.  Specific  gravity  4.1  to  4.2, 
hardness  5,5  to  6.  Before  the  blow-pipe  it  yields 
manganic  oxide,  giving  off  oxygen.  It  is  soluble 
in  hydrochloric  acid,  chlorine  being  evolved.  The 
powdered  ore  colors  sulphuric  acid  red.  Psilome- 
lane contains  from  40  to  50  per  cent,  of  manganese, 
and  some  baryta  and  potassa.  A  solution  in  hydro- 
chloric acid  of  the  variety  containing  baryta  gives 
a  heavy  white  precipitate  with  sulphuric  acid. 

Rhodocrosite  or  Manganese  Carbonate  oc- 
curs in  spherical  and  nodular  aggregations  of 
cauliform  texture  or  in  compact  masses  of  granu- 
lar texture.  It  is  rose-red  to  raspberry-red  in 
color,  by  weathering  frequently  brownish,  with 
a  glassy  or  mother-of-pearl  lustre.     It  cleaves  like 


230      prospector's  field-book  and  guide. 

calcite.  It  contains  61.4  per  cent,  of  manganese 
protoxide  and  38.6  per  cent,  of  carbonic  acid, 
with  part  of  manganese  frequently  replaced  by  cal- 
cium, magnesium,  or  iron.  Specific  gravity  3.3 
to  3.6  ;  hardness  3.5  to  4.5.  Before  the  blow-pipe 
it  is  infusible  and  becomes  black.  From  simi- 
lar minerals  it  is  distinguished  by  its  rose-color  and 
the  manganese  reaction  with  soda  and  borax ;  and 
from  silicate  of  manganese  by  its  inferior  hardness, 
its  effervescence  with  acids  and  its  non-fusibility. 

The  manganese  in  ores  of  the  third  class  is  valu- 
able, even  where  the  silver  alone  is  sought,  as  it 
facilitates  the  work  whereby  the  silver  is  extracted; 
this  it  does  because  of  its  fluxing  quality. 

Virginia,  Georgia  and  Arkansas  are  the  chief  pro- 
ducing States. 

The  geological  position  of  manganese  in  some 
places  seems  to  be  the  same  as  with  the  red  hema- 
tite, as  in  Virginia. 

In  Tennessee  it  is  found  in  the  foot-hills  of  the 
mountains,  four  miles  from  Newport,  Cocke  Co.,  in 
pockets,  and  is  a  black  oxide  of  48  per  cent,  metal- 
lic manganese. 

In  Vermont  it  is  found  near  a  siliceous  limestone, 
and  in  the  vicinity  of  brown  hematite  ores.  It  ex- 
ists in  the  triassic  formation  in  Bosnia. 

In  North  Carolina  it  is  found  in  light-colored 
gneissic  schists. 


CHAPTER  XIII. 

VARIOUS    USEFUL    MINERALS. 

Alum.  This  name  is  applied  to  a  group  of  min- 
erals which  are  hydrous  sulphates  of  aluminium 
with  potash,  soda,  ammonia,  magnesia,  etc.  They 
all  crystallize  in  the  regular  system,  are  soluble  in 
water  and  have  an  astringent  sweetish  taste.  Hard- 
ness, 2  to  2.5 ;  specific  gravity,  1.8.  Potash  alum 
is  the  most  common,  and  is  usually  found  in  the 
form  of  an  efflorescence  or  an  incrustation,  with  a 
mealy  and  sometimes  a  fibrous  structure.  It  is 
abundant  in  clays,  argillaceous  schists,  which,  when 
largely  impregnated  with  alum,  are  called  alumi- 
nous schists  or  shales. 

Soda  alum  has  a  general  resemblance  to  potash 
alum  but  is  rather  more  soluble  in  water.  Magnesia 
alum  occurs  in  silky-lustred  fibrous  masses.  Iron 
alum  forms  yellowish- white  silky  masses. 

It  differs  somewhat  from  the  other  alums  in  turn- 
ing red  when  heated.  Alum  is  used  in  dyeing  and 
calico  printing,  candle  making,  dressing  skins,  clari- 
fying liquids,  and  in  pharmacy. 

Apatite,  Phosphate  of  Lime,  occurs  in  six-sided 
prisms,  also  in  masses.  It  is  transparent  or  opaque  ; 
colorless,  white,  yellowish,  green,  violet,  with  a 
(231) 


232      prospector's  field-book  and  guide. 

glassy  lustre,  and  yields  always  a  white  streak. 
Fracture,  conchoidal  or  uneven.  Specific  gravity 
3.16  to  3.22 ;  hardness  5.  In  thin  laminae  it  is 
fusible  with  difficulty  before  the  blow-pipe  ;  when 
moistened  with  sulphuric  acid,  tinges  the  flame 
greenish.  It  is  soluble  in  hydrochloric  and  nitric 
acids  without  effervescence.  From  beryl  it  is  dis- 
tinguished by  its  inferior  hardness  and  its  solubility 
in  acids.  It  occurs  in  rocks  of  various  kinds,  but 
more  frequently  in  those  of  a  metamorphic  crystal- 
line character,  as  in  Laurentian  gneiss,  which  is 
usually  hornblendic,  granitic  or  quartzose  in  char- 
acter, in  Canada,  and  in  association  with  granular 
limestone.  It  is  also  found  as  an  accessory  mineral 
in  metalliferous  veins,  especially  those  of  tin,  and 
beautifully  crystallized  and  of  various  colors  in 
many  eruptive  rocks.  It  also  occurs  in  veins  by 
itself,  mostly  in  limestone,  but  sometimes  in  gran- 
ites and  schists.  In  these  deposits  apatite  is  also 
found  as  concretions,  sometimes  showing  a  radiated 
structure,  but  of  an  earthy  appearance  externally. 
In  sedimentary  formations  where  a  considerable 
accumulation  of  fossils  has  provided  the  phosphate 
of  lime  it  occurs  in  two  principal  forms,  namely 
coprolites,  which  are  excreta  of  large  animals, 
especially  saurians,  and  concretions  formed  at  the 
expense  of  the  same  coprolites,  together  with  shells, 
bones,  etc.  The  richest  of  these  deposits  are  from 
Lower  Cretaceous  to  Lower  Jurassic  in  age,  but 
phosphatic  deposits  are  found  and  worked  in  sedi- 
mentary deposits  of  all  ages. 


VARIOUS   USEFUL   MINERALS.  233 

The  principal  use  of  apatite  is  as  a  source  of  phos- 
phoric acid  and  phosphorus,  and  before  the  dis- 
covery of  the  phosphate-rock  deposits  in  Florida 
was  largely  sold  to  the  manufacturers  of  fertilizers. 

Arsenic  is  found  in  the  mineral  kingdom  partly 
in  a  metallic  state,  partly  in  combination  with 
oxygen,  sulphur  and  other  bodies. 

1.  Native  Arsenic  occurs  seldom  distinctly  crystal- 
lized, but  usually  in  fine  granular,  spherical  or 
nodular  masses.  Specific  gravity  5.7  to  5.8  ;  hard- 
ness 3.5  ;  brittle ;  uneven  and  fine-grained  fracture  ; 
metallic  lustre ;  color,  whitish  lead-gray,  usually 
with  a  grayish-black  tarnish ;  evolves  an  odor 
of  garlic  on  breaking ;  contains  occasionally  more 
or  less  iron,   cobalt,  nickel,  antimony  and  silver. 

Before  the  blow-pipe  it  quickly  volatilizes  before 
fusing,  giving  off  white  fumes  having  an  odor 
of  garlic.  Native  arsenic  occurs  especially  in  veins 
in  crystalline  slates  and  transition  rocks  in  sub- 
ordinate quantities  associated  with  ores  of  silver, 
lead,  cobalt  and  nickel. 

2.  Realgar,  with  70.029  per  cent,  of  arsenic  and 
29.971  per  cent,  sulphur.  Color,  red ;  crystallizes 
clinorhombic ;  fracture  conchoidal  to  splintery ; 
hardness  1.5  to  2.0  ;  specific  gravity  3.4  to  3.6.  It 
it  but  slightly  affected  by  acids ;  soluble  with  a  de- 
posit of  sulphur  in  aqua  regia,  and  in  concentrated 
potash  lye  with  separation  of  dark  brown  sulphuret 
of  arsenic.  From  ruby  silver  and  cinnabar,  it  is 
readily  distinguished  by  its  inferior  hardness, 
slighter  specific  gravity  and  orange-yellow  streak, 


234      prospector's  field-book  and  guide, 

the  streak  of  the  two  above-mentioned  minerals 
being  cochineal-red. 

3.  Orpiment,  with  69.9  per  cent,  of  arsenic  and 
39.1  per  cent,  of  sulphur ;  occurs  in  nature,  but  for 
industrial  purposes  is  mostly  artificially  prepared. 
The  mineral  has  a  lustrous  lemon-yellow  or  orange- 
yellow  color,  is  cleavable  into  thin,  flexible,  trans- 
parent laminae  ;  hardness  1.5  to  2  ;  specific  gravity 
3.4  to  3.5  ;  soluble  in  nitric  acid,  potash  lye  and 
ammonia. 

Asbestus.  Fibrous.  Color,  green  or  white.  The 
asbestus  of  commerce  is  practically  a  finely  fibrous 
form  of  serpentine,  that  is  to  say,  it  is  essentially  a 
hydrated  magnesium  silicate.  Every  deposit  of  ser- 
pentine is  a  possible  repository  of  asbestus.  It 
occurs  in  seams  half  an  inch  to  several  inches  in 
width,  running  parallel  to  or  crossing  one  another, 
the  width  of  each  seam  making  the  length  of  the 
fibre.  Canada  furnishes  at  present  a  large  portion 
of  the  world's  supply  of  asbestus.  The  profitable 
mining,  however,  is  at  present  confined  to  a  small 
area  in  the  great  serpentine  belt  of  the  Province  of 
Quebec,  that  lies  to  the  south  of  the  St.  Lawrence 
River.  In  the  form  of  a  rough  cloth  asbestus  is 
used  for  covering  steam-pipes,  and  for  many  pur- 
poses requiring  an  incombustible  material. 

Barytes,  or  barium  sulphate,  commonly  called 
heavy  spar,  occurs  in  tabular,  glassy  crystals,  and 
also  in  dull  masses  in  veins  of  various  rock  forma- 
tions. Color,  white  or  tinted  ;  transparent  or  trans- 
lucent ;  lustre,  vitreous  or  pearly.     Specific  gravity, 


VARIOUS    USEFUL    MINERALS.  235 

4.3  to  4.7.  Hardness,  3  to  3.5.  It  is  readily  dis- 
tinguished by  its  great  comparative  weight.  When 
heated  in  the  blow-pipe  flame  splinters  fly  off  the 
crystals.  It  fuses  with  difficulty,  and  imparts  a 
green  tinge  to  the  flame.  After  fusion  with  soda,  it 
stains  a  silver  coin  black.  It  is  not  acted  upon  by 
acids. 

In  the  United  States  barytes  is  found  in  many 
places,  it  being  mined  in  Virginia,  Missouri,  New 
Jersey  and  other  states.  It  frequently  occurs  in 
connection  with  lead  and  zinc  deposits  forming  the 
gangue  of  the  metal-bearing  vein.  The  best  varie- 
ties of  barytes  are  the  white  and  gray.  The  chief 
use  of  barytes  is  as  a  pigment,  as  a  cheaper  substi- 
tute for  white  lead.  It  is  also  used  as  a  make- 
weight by  paper  manufacturers,  etc. 

The  carbonate  of  barium,  with&rite,  is  a  much  less 
common  mineral  than  the  sulphate.  It  sometimes 
occurs  in  crystals,  but  the  more  common  form  is 
that  in  fibrous  masses.  It  occurs  in  veins.  It 
fuses  easily  in  the  forceps,  and  gives  a  yellow-green 
flame.  In  hydrochloric  acid  it  dissolves  with  effer- 
vescence, the  solution  yielding  a  heavy  white  pre- 
cipitate (barium  sulphate)  if  a  little  sulphuric  acid 
is  added.  Witherite  is  used  in  the  refining  of 
sugar,  and  also  in  the  manufacture  of  plate  glass. 

Borax.  Monoclinic.  Fracture,  conchoidal.  Lus- 
tre, vitreous  to  resinous.  Color,  white,  sometimes 
grayish,  bluish,  or  greenish.  Streak,  white.  Taste, 
slightly  alkaline  and  sweetish.  Translucent  to 
opaque.      Principal    producing    localities    in    the 


236      prospector's  field-book  and  guide. 

United  States  :  the  Columbus  and  Rhodes  marshes 
in  Nevada,  the  Saline  marshes  in  California.  In 
the  Calico  district  the  borate  of  lime  is  taken  from 
a  fissure  vein,  and  this  district  is  the  only  place  in 
the  world  where  deep  mining  for  borax  is  carried  on. 

Borax  is  used  in  medicine  and  as  an  antiseptic 
by  meat  packers  and  others.  Its  chief  use,  how- 
ever, is  as  a  flux  in  metallurgical  operations,  in 
enameling,  glazing  of  pottery  and  in  the  manu- 
facture of  glass. 

Clays.  The  clays  are  all  products  of  alteration 
from  other  minerals.  Their  composition  is  variable 
and  they  do  not  crystallize.  The  true  clays  are  all 
plastic  and  refractory  to  a  greater  or  less  degree, 
and  on  these  properties  their  value  for  industrial 
purposes  depends.  Pure  kaolin  is  the  type  of  all 
the  clays. 

The  presence  of  alkalies  in  clays  is  objectionable, 
as  it  renders  them  fusible,  as  also  do  many  other 
oxides.  Iron  is  not  only  objectionable  on  the  score 
of  fusibility,  but  also  as  coloring  matter.  The 
presence  of  too  large  a  proportion  of  water,  carbonic 
acid  or  organic  matter,  causes  clay  to  contract 
under  the  action  of  fire,  and  the  same  result  will 
ensue  if  the  clay  is  partially  fusible. 

The  soft  clays  are  divided  as  follows  : 

Kaolin,  porcelain  clay  or  China  clay.  This  is  a 
product  of  decomposition  of  feldspar  and  other  min- 
erals, and  never  occurs  in  any  crystalline  form.  Its 
composition  varies  somewhat  according  to  the  source 
from  which  it  has  been  derived.     In  all  cases  it  is  a 


VARIOUS   USEFUL   MINERALS.  237 

hydrated  silicate  of  alumina,  and  its  usual  source  is 
feldspar.  It  is  a  friable,  soft  substance  of  a  white 
yellow,  or  flesh-red  color,  and  capable  of  resisting 
the  highest  heat  of  a  porcelain  furnace.  It  usually 
contains  more  or  less  silica  in  an  uncombined  state. 
Its  specific  gravity  is  2.2.  Kaolin  is  almost  entirely 
from  the  older  feld spathic  rocks,  while  clays  are 
generally  derived  from  younger  rocks. 

Pottery  or  plastic  clay  is  not  so  pure  as  Kaolin  con- 
taining a  large  percentage  of  iron. 

Bole  is  a  hydrated  silicate  of  alumina  and  iron, 
of  a  somewhat  variable  composition,  but  generally 
containing  about  42  per  cent,  of  silica  and  24  per 
cent,  of  water.  It  also  contains  a  large  amount  of 
ferric  oxide,  which  gives  it  its  yellow-red  or  brown- 
ish-black color.  It  is  soft  and  greasy,  translucent 
or  opaque,  adheres  to  the  tongue,  and  falls  to  pieces 
with  a  crackling  noise  when  immersed  in  water. 
The  hardness  is  1.5  and  the  specific  gravity  1.4  to 
2.     It  fuses  with  facility  into  a  greenish  enamel. 

Fuller's  earth  is  a  kind  of  clay  composed,  when 
pure,  of  45  per  cent,  silica,  20  to  25  per  cent,  alum- 
ina, and  water.  It  was  formerly  largely  used  as  an 
absorbent  in  fulling  or  freeing  woolen  fabrics  and 
cloth  from  fatty  matters,  but  in  modern  times  other 
substances  have  been  substituted,  and  the  consump- 
tion of  it  has  greatly  fallen  off. 

Coal  (Mineral).  Massive,  uncrystalline.  Color, 
black  or  brown ;  opaque.  Brittle  or  imperfectly 
sectile.  Hardness  0.5  to  2.5.  Specific  gravity  1.2 
to  1.80.     Coal  is  composed  of  carbon  with  some 


oxygen  and  hydrogen,  more  or  less  moisture,  and 
traces  also  of  nitrogen,  besides  some  earthy  material 
which  constitutes  the  ash. 

Anthracite  {Glance  coal,  Stone  coal).  Lustre  high, 
not  resinous,  sometimes  submetallic.  Color,  gray- 
black.  Hardness  2  to  2.5.  Specific  gravity,  if  pure, 
1.57  to  1.67.  Fracture  often  conchoidal.  Good 
anthracite  contains  78  to  88  per  cent,  of  fixed 
carbon. 

Bituminous  coal.  Color,  black.  Lustre,  usually 
somewhat  resinous.  Hardness  1.5  to  2 ;  specific 
gravity  1.2  to  1.4.  Contains  usually  75  to  85  per 
cent,  of  carbon. 

Cannel  coal.  Very  compact  and  even  in  texture, 
with  little  lustre,  and  fracture  largely  conchoidal. 

Brown  coal  (often  called  lignite).  Color,  black  to 
brownish-black.  Contains  52  to  65  per  cent,  of 
fixed  carbon. 

Jet  resembles  cannel  coal,  but  is  harder,  of  a 
deeper  black  and  higher  lustre.  It  takes  a  brilliant 
polish  and  is  set  in  jewelry. 

Dolomite  is  composed  of  carbonic  acid,  lime, 
magnesia.  It  occurs  in  rhombohedrons,  faces  often 
curved.  It  is  frequently  granular  or  massive; 
white  or  dull  tinted  ;  and  glassy  or  pearly.  Specific 
gravity  2.8  to  2.9 ;  hardness  3.5  to  4.  Effervesces 
in  nitric  acid  and  dissolves  more  slowly  than  calc 
spar.  Yields  quicklime  when  burnt.  Occurs  in 
extensive  beds  of  various  ages  like  limestone.  It  is 
used  as  a  building-stone  and  in  the  manufacture 
of  Epsom  salts.  It  is  difficult  to  distinguish  from 
calcite  without  chemical  analysis. 


VARIOUS    USEFUL    MINERALS.  239 

Feldspar,  Orthoclase,  is  composed  of  silica 
64.20,  alumina  18.40,  potash  or  soda  (lime)  16.95. 
Crystallized  or  in  irregular  masses.  Opaque ; 
usually  flesh-red  or  white,  or  of  various  dull  tints. 
Lustre,  glassy  or  pearly ;  fracture,  irregular,  but  in 
some  directions  it  splits  with  an  even,  glimmering 
cleavage  face.  Specific  gravity,  2.3  to  2.8  ;  hardness 
6.  Before  the  blow-pipe  it  fuses  with  difficulty  ;  is 
not  touched  by  acids.  Where  found  in  sufficient 
quantity  to  be  of  industrial  value,  it  is  usually  ob- 
tained from  veins  in  granite  or  pegmatite.  The 
minerals  associated  with  feldspar  are  chiefly  quartz 
and  mica,  while  tourmaline  and  topaz  also  occur 
commonly.  Feldspar  is,  to  a  limited  extent,  em- 
ployed in  the  manufacture  of  glass,  but  the  chief 
use  for  it  is  as  a  china  glaze  and  as  a  glass-forming 
ingredient  in  the  body  of  the  porcelains. 

One  of  the  finest  varieties  of  feldspar  is  that 
known  as  Adularia,  from  Mount  Adula,  near,  the  St. 
Gothard  Pass,  where  it  is  found  redeposited  from 
the  rock  mass  in  veins  and  cavities.  It  consists  of 
silica  64,  alumina  20,  lime  2,  and  potash  14.  Moon- 
stone is  another  variety,  with  bluish- white  spots  of  a 
pearly  lustre.  Sunstone  is  another,  with  a  pale  yel- 
low color  with  minute  scales  of  mica.  Aventurine, 
feldspar  sprinkled  with  iridescent  spots  from  the 
presence  of  minute  particles  of  titanium  or  iron. 
The  last  three  varieties  are  employed  as  gem-stones, 
being  occasionally  set  in  brooches,  but  are  too  soft 
for  rings. 

A  beautiful  variety  of  orthoclase  known  as  Ama~ 


240      prospector's  field-book  and  guide. 

zon  stone  occurs  in  large  green  crystals  near  Pike's 
Peak,  in  Colorado,  in  Siberia  and  elsewhere. 

Flint  consists  of  silica,  which  in  a  very  fine  con- 
dition has  been  separated  from  the  surrounding 
rock,  and  which,  attracted  to  some  organic  or  inor- 
ganic nucleus,  and  sometimes  only  to  itself,  has 
grown  in  successive  layers  or  bands,  often  of  different 
colors.  Hornstone  or  chert  is  allied  to  flint,  but  it  is 
more  brittle  and  it  takes  its  color — dirty  grey,  red, 
and  reddish-yellow,  green  or  brown — from  the  rocks 
in  which  it  is  found.  It  occurs  in  portions  of  sand- 
stone rocks  usually  containing  a  little  lime,  the  fine 
silica  being  seemingly  collected  into  one  spot. 

Fluorspar,  Fluorite,  consists  of  48.7  per  cent, 
of  fluorine  and  51.3  per  cent,  of  calcium.  It  occurs 
in  cubes  or  octahedrons,  and  also  in  masses.  It  is 
transparent  or  opaque ;  white  or  light  violet,  blue, 
green  or  yellow  ;  sometimes  layers  of  different  tints 
in  the  same  piece.  Lustre,  glassy.  It  breaks  with 
smooth  cleavage  planes  parallel  to  the  octahedral 
faces.  Specific  gravity  3  to  3.2  ;  hardness  4.  Be- 
fore the  blow-pipe  it  is  fusible  with  difficulty  to  an 
enamel.  It  is  used  in  the  manufacture  of  hydro- 
fluoric acid,  with  which  glass  is  etched,  and  also  as 
a  flux  for  copper  and  other  ores.  Sometimes  it  is 
employed  for  ornaments,  especially  massive  pieces, 
they  taking  a  high  polish.  It  occurs  in  veins  with 
lead  and  silver  ores. 

Graphite,  Plumbago,  Blacklead,  consists  es- 
sentially of  carbon,  in  mechanical  admixture  with 
varying  proportions  of  silicious  matter,  as  clay,  sand 


VARIOUS    USEFUL    MINERALS.  241 

or  limestone.  It  occurs  in  hexagonal  crystals,  but 
usually  in  foliated  or  massive  layers.  Color,  steel 
gray  to  bluish  black.  Hardness  very  slight,  0.5  to 
1.  Soils  the  fingers,  makes  a  mark  upon  paper,  and 
feels  greasy.  The  specific  gravities  of  different 
kinds  of  graphite  vary  according  to  the  content  of 
foreign  admixtures,  but  lie  within  the  limits  of 
2.105  and  2.5857.  Graphite  is  not  affected  by  acids 
and  strongly  resists  other  chemical  agents.  It  is 
largely  used  in  the  manufacture  of  pencils,  crucibles, 
stove  polish,  and  lubricants  for  heavy  machinery. 
It  is  found  in  various  parts  of  the  world,  chiefly  in 
crystalline  limestone,  in  gneiss  and  mica  schists, 
frequently  replacing  the  mica  in  the  latter  so  that 
they  become  actual  graphite  schists.  The  chief 
source  whence  the  bulk  of  the  mineral  has  for 
many  years  been  derived  is  the  Island  of  Ceylon. 
In  the  United  States  graphite  is  obtained  from  a 
mountain,  locally  known  as  the  Blacklead  Moun- 
tain, which  rises  close  to  the  village  of  Ticonderoga, 
Essex  Co.,-  New  York.  The  graphite  beds  are 
interstratified  between  gneissic  rocks.  The  beds 
dip  at  an  angle  of  45°.  The  ore  in  them  is  chiefly 
of  the  foliated  variety,  and  is  mixed  with  gneiss 
and  quartz  in  the  beds  in  veins  or  layers  from  1  to 
8  inches  in  thickness,  some  of  the  deposits  being 
richer  than  others.  One  of  these  has  been  followed 
to  a  depth  of  350  feet.  It  is  found  of  varying  thick- 
ness and  it  opens  out  at  times  into  pockets. 

Graphite   is   said    to    occur   in    great    purity   in 
different   localities   in   Albany    Co.,   Wyoming,  in 
16 


242      prospector's  field-book  and  guide. 

veins  from  1  foot  6  inches  to  5  feet  thick.  At 
Pilkin,  Gunnison  Co.,  it  occurs  massive  in  beds  2 
feet  thick,  but  of  impure  quality.  It  is  also  found 
in  the  coal  measures  of  New  Mexico,  in  Nevada,  in 
Utah,  and  in  the  Black  Hills  of  South  Dakota. 

The  value  of  graphite  depends  upon  the  amount 
of  its  carbon.  To  test  the  purity  of  graphite,  pul- 
verize and  then  dry  at  about  350°  F.  20  grains 
of  it ;  then  place  it  in  a  tube  of  hard  glass  4  to  5 
inches  long,  half  an  inch  wide,  and  closed  on  one 
end.  Add  twenty  times  as  much  dried  oxide 
of  lead  and  mix  intimately.  Weigh  the  tube  and 
contents,  and  afterwards  heat  before  the  blow-pipe 
until  the  contents  are  completely  fused  and  no 
longer  evolve  gases.  Ten  minutes  will  suffice  for 
this.  Allow  the  tube  to  cool,  and  weigh  it.  The 
loss  in  weight  is  carbonic  acid.  For  every  28  parts 
of  loss  there  must  have  been  12  of  carbon. 

Gypsum  is  a  hydrous  sulphate  of  lime,  and  is 
composed  of  sulphuric  acid,  lime  and  water.  It 
occurs  in  prisms  with  oblique  terminations,  some- 
times resembling  an  arrow-head.  It  is  transparent 
or  opaque,  white  or  dull  tinted,  with  a  glassy, 
pearly  or  satin  lustre.  Cleavage  occurs  easily  in 
one  direction  ;  specific  gravity  2.3  ;  hardness  2  ;  can 
be  readily  cut  with  the  knife.  In  the  blow-pipe 
flame  it  becomes  white  and  opaque  without  fusing, 
and  can  then  be  easily  crumbled  between  the 
fingers.  Nitric  acid  does  not  cause  effervescence. 
It  occurs  .in  fissures  and  in  stratified  rocks,  often 
forming  extensive  beds.     When  pure    white   it   is 


VARIOUS    USEFUL    MINERALS.  243 

called  Alabaster  ;  when  transparent,  Selenite  ; 
and  when  fibrous,  Satin  Spar.  When  burnt, 
gypsum  loses  its  water  and  falls  to  powder.  This 
powder,  called  Plaster  of  Paris,  which  is  per- 
fectly white  when  free  from  iron,  possesses  the 
property  of  reabsorbing  the  water  lost,  and  in  a 
very  short  time  of  assuming  again  the  solid  state, 
expanding  slightly  is  so  doing.  It  is  this  last 
property  that  renders  plaster  of  Paris  so  valuable 
for  obtaining  casts.     It  is  also  used  as  a  fertilizer. 

Infusorial  Earth  is  an  earthy,  sometimes 
chalk-like  siliceous  material,  entirely  or  largely 
made  up  of  the  microscopic  shells  of  the  minute 
organisms  called  diatoms.  It  occurs  in  beds  some- 
times of  great  extent,  sometimes  beneath  peat  beds, 
and  is  obtained  for  commerce  in  Maine,  New 
Hampshire,  Massachusetts,  Virginia,  California, 
Nevada,  Missouri.  It  feels  harsh  between  the  fin- 
gers and  is  of  a  white  or  grayish  color,  but  often 
discolored  by  various  impurities.  Infusorial  earth 
is  used  as  a  polishing  powder,  electro-silicon  being 
the  trade-name  of  one  kind  much  used  for  polishing 
silver.  It  is  also  used  for  making  soda  silicate  and 
for  purposes  of  a  cement.  Being  a  bad  conductor 
of  heat,  it  is  applied  as  a  protection  to  steam  boilers 
and  pipes.     It  is  also  employed  for  filling  soap. 

Lithographic  Limestone.  The  only  stone  yet 
found  possessing  the  necessary  qualifications  for 
lithographic  work  is  a  fine-grained  homogeneous 
limestone,  breaking  with  an  imperfect  shell-like  or 
conchoidal  fracture,  and,  as  a  rule,  of  a  gray,  drab 


244 

or  yellowish  color.  A  good  stone  must  be  suffi- 
ciently porous  to  absorb  the  greasy  compound 
which  holds  the  ink,  soft  enough  to  work  readily 
under  the  engraver's  tool,  yet  not  too  soft,  and  must 
be  firm  in  texture  throughout  and  entirely  free  from 
all  veins  and  inequalities.  The  best  stone,  and  in- 
deed the  only  one  which  has  yet  been  found  to  fill 
satisfactorily  all  these  requirements,  occurs  at  Solen- 
hofen,  Bavaria.  These  beds  are  of  Upper  Jurassic 
age,  and  form  a  mass  of  some  eighty  feet  in  thick- 
ness. The  prevailing  tints  of  the  stone  are  yellow- 
ish or  drab. 

In  the  United  States  materials  partaking  of  the 
nature  of  lithographic  stone  have  been  reported 
from  various  localities,  but  it  is  believed  all  have 
failed  as  a  source  of  supply  of  the  commercial  arti- 
cle, though  it  is  possible  that  ignorance  as  to  the 
proper  methods  of  quarrying  may  in  some  cases 
have  been  a  cause  of  failure. 

Meerschaum  or  Sepiolite  is  a  manganese  sili- 
cate. When  pure,  it  is  very  light ;  and,  when  dry, 
it  will  float  upon  water.  It  will  be  recognized  by 
its  property,  when  dry,  of  adhering  to  the  tongue, 
and  by  its  smooth,  compact  texture.  It  is  generally 
found  in  serpentine,  in  which  rock  it  occurs  in  nod- 
ular masses ;  but  it  is  also  found  in  limestones  of 
tertiary  age.  It  is  of  a  snowy-white  color  and  a 
useful  substance  when  found  in  quantity,  being 
much  employed  for  the  bowls  of  tobacco  pipes,  and 
for  this  purpose  is  mined  in  Asia  Minor. 

Micas.     These  are  silicates  of  alumina  with  pot- 


VARIOUS    USEFUL    MINERALS.  245 

ash,  rarely  soda  or  lithia,  also  magnesia,  iron  and 
some  other  elements.  Always  crystallized  in  thin 
plates,  which  may  be  split  into  extremely  thin  flex- 
ible layers.  Transparent  in  thin  layers.  Color, 
white,  green,  brown  to  black.  Specific  gravity  2.7 
to  3.1.  Hardness  2  to  2.5  ;  very  easily  scratched 
with  a  knife.  Before  the  blow-pipe  it  whitens,  but 
is  infusible  except  on  thin  edges.  When  it  can  be 
obtained  in  large  sheets,  mica  is  very  valuable.  It 
is  sometimes  used  in  the  place  of  window  glass  on 
board  ship,  for  stoves  and  for  chimneys  for  lamps. 
The  ground  material  is  used  as  a  lubricant  and  in 
making  ornamental  and  fire-proof  paint. 

Biotite,  or  black  mica,  contains  more  magnesia 
than  alumina.  It  is  often  present  in  eruptive  rocks, 
especially  some  granites.  Muscovite,  or  white  mica, 
on  the  contrary,  contains  more  alumina  than  mag- 
nesia, and  as  it  also  contains  potash  in  small  but 
appreciable  quantities,  it  is  sometimes  called  potash 
mica,  and  biotite  magnesian  mica.  Muscovite  is  an 
important  mineral  to  the  tin  miner,  since  it  is 
always  found  in  that  class  of  granite  in  which  tin- 
stone occurs,  and  with  quartz  alone  forms  the  rock 
called  greisen,  which  is  very  generally  associated 
with  tin.  The  rock  in  which  large  sheets  of  mica 
are  found  is  called  by  some  geologists  pegmatite,  and 
has  the  same  composition  as  granite  itself,  but  the 
crystals  are  of  a  larger  size. 

Molybdenum.  The  sulphide  occurs  native  as 
Molybdenite  in  crystallolaminar  masses  or  tabular 
crystals,  having  a  strong  metallic  lustre  and   lead- 


246      prospector's  field-book  and  guide. 

gray  color,  and  forming  a  greenish-black  streak 
which  is  best  seen  by  drawing  a  piece  across  a  china 
plate.  Specific  gravity  4.5  to  4.6  ;  hardness  1  to 
1.5  ;  easily  scratched  by  the  nail.  It  contains  58.9 
of  molybdenum  and  41.1  per  cent,  of  sulphur.  It 
occurs  sparingly  in  granite,  syenite  and  chlorite 
schists,  and  is  sometimes  mistaken  for  graphite,  from 
which  it  is,  however,  readily  distinguished  by  the 
streak,  that  of  graphite  being  black.  Before  the 
blow-pipe  it  is  infusible,  but  tinges  the  flame  faint 
green.  Heated  on  charcoal  for  a  long  time  it  gives 
off  a  faint  sulphurous  odor  and  becomes  encrusted 
white.  Its  chief  use  is  in  the  preparation  of  a  blue 
color. 

Nitre  or  Saltpetre  is  white,  inodorous,  not  de- 
liquescent ;  at  a  red  heat  it  is  decomposed  with  evo- 
lution first  of  oxygen.  It  has  a  cooling  saline  taste, 
a  vitreous  lustre,  a  hardness  of  2,  and  specific  grav- 
ity of  1.9.  It  is  usually  found  native  as  an  efflo- 
rescence on  the  soil.  It  is  constantly  forming  in  the 
neighborhood  of  decomposing  organic  matter,  espe- 
cially in  stables  and  certain  caves,  such  as  those  in 
Ceylon,  America  and  elsewhere,  which  are  inhab- 
ited by  a  large  number  of  bats.  It  is  distributed 
through  many  limestones  and  soils. 

Rock  Salt  has  the  character  of  ordinary  table 
salt,  but  is  more  or  less  impure.  Occurs  in  beds 
interstratified  with  sandstones  and  clays,  which  are 
usually  of  a  red  color  and  associated  with  gypsum. 
Specific  gravity  2  to  2.25 ;  hardness  2  to  2.5.  It 
contains  39.30  per  cent,  of  sodium  and  60.66  per 


VARIOUS    USEFUL    MINERALS.  247 

cent,  of  chlorine,  but  most  samples  contain  clay  and 
a  little  lime  and  magnesia.  The  surface  indications 
of  rock  salt  are  brine  springs  supporting  a  vegeta- 
tion like  that  near  the  sea  coast,  also  occasional 
sinking  of  the  soil  caused  by  the  removal  of  the 
subterranean  bed  of  salt  by  spring  water.  Rock 
salt  is  obtained  by  sinking  wells  from  which  the 
brine  is  pumped  and  evaporated  in  large  pans,  or 
by  mining,  the  same  as  for  any  other  ore. 

Salt  deposits  occur  in  the  strata  of  all  ages,  from 
the  Silurian  to  those  now  forming.  In  North 
America  a  chain  of  mountains  extends  along  the 
west  bank  of  the  river  Missouri  for  a  length  of  80 
miles  by  45  in  breadth,  and  of  considerable  height. 
These  mountains  consist  largely  of  rock  salt.  The 
same  formation  extends  into  Kentucky,  where  the 
deposits  are  called  "  licks,"  because  of  the  licking 
of  the  rocks  and  soil  by  the  herds  of  wild  cattle 
that  once  roamed  there.  In  Michigan,  in  the 
neighborhood  of  Marine  City,  a  well  was  sunk  to  a 
depth  of  1,633  feet,  when  a  deposit  of  rock  salt  was 
entered  and  penetrated  to  a  depth  of  over  1,500  feet 
without  the  tools  passing  through  it.  The  deposit 
seems  to  increase  in  thickness,  but  it  is  reached  at 
an  increasing  depth  as  it  trends  in  a  south-westerly 
direction  by  Inverhuron,  Kincardine,  and  War- 
wick. 

An  extraordinary  superficial  deposit  of  rock  salt 
occurs  in  Petite  Anse  Island,  parish  Iberia,  Lou- 
isiana. The  island  is  about  two  miles  in  diameter, 
and    the   salt   deposit  on   it   is   known   to    extend 


248      prospector's  field-book  and  guide. 

under  165  acres.  It  is  covered  with  16  feet  of  soil. 
It  has  been  proved  to  a  depth  of  80  feet.  The  salt 
occurs  in  solid  masses  of  pure  crystals,  and  it  is 
taken  out  by  blasting. 

The  bulk  of  the  manufactured  salt  in  North 
America  is  obtained  from  brine  springs.  Valuable 
and  productive  springs  are  worked  in  Syracuse  and 
Salina  districts,  New  York,  and  in  Ohio.  Some  of 
these  arise  from  a  red  sandstone  whose  geological 
place  is  said  to  be  below  the  coal  measures. 

Rock  salt  has  been  discovered  in  Nevada.  The 
southern  termination  of  the  deposits  is  about  seven 
miles  from  the  uppermost  limit  to  the  navigation  of 
the  Colorado  river.  Some  of  the  specimens  are 
sufficiently  pure  and  transparent  to  allow  of  small 
print  being  read  through  them.  In  the  same  state 
there  is  an  interesting  salt  lake,  the  water  of  which 
contains  about  two  pounds  of  salt  and  soda  to  every 
gallon.  It  is  several  hundred  feet  deep.  Soda  and 
salt  have  been  obtained  from  this  lake  for  sev- 
eral years  by  natural  evaporation.  The  water  is 
pumped  into  tanks  at  the  beginning  of  the  summer 
season.  It  is  left  in  these  tanks  during  the  warm 
summer  months  until  the  frost  sets  in.  When  the 
first  frost  comes  the  soda  is  precipitated  in  crystals. 
The  water  is  then  drained  off  into  a  large  poncl, 
where  slow  evaporation  goes  on,  and  a  deposit  of 
common  salt  is  obtained. 

The  famous  salt  mine  of  Wieliezka,  near  Cracow, 
in  Galicia,  has  been  worked  since  the  year  1251, 
and  it  has  still  vast  reserves  of  the  mineral. 


VARIOUS    USEFUL    MINERALS.  249 

Slate  is  an  argillaceous  shale  easily  recognized 
by  its  cleavability,  and  varies  in  color  from  light 
sea-green  and  gray  to  red,  purple  and  black.  It  has 
been  formed  by  sedimentary  deposits,  and  now  con- 
stitutes extensive  beds  in  the  Silurian  formation. 

Sulphur.  Native  sulphur  or  brimstone  occurs 
crystallized  or  massive  in  volcanic  regions  and  in 
beds  of  gypsum.  Color,  yellow  ;  lustre,  resinous  ; 
specific  gravity  2.1 ;  hardness  1.5  to  2.5.  It  is 
fusible  and  burns  with  a  blue  flame  and  well-known 
odor.  It  is  frequently  found  contaminated  with 
clay  or  pitch.  Italy  and  Sicily  together  furnish 
the  greater  part  of  the  sulphur  of  commerce,  the 
major  portion  coming  from  Sicily.  The  most  im- 
portant deposits  of  brimstone  in  the  United  States 
are  found  in  Utah  at  Cove  Creek,  22  miles  from 
Beaver,  while  there  are  other  deposits  at  a  point 
about  12  miles  southwest  from  Frisco.  Large  de- 
posits of  sulphur  are  knowTn  to  exist  in  Wyoming, 
California  and  Arizona,  but  none  of  them  is  at 
present  available  for  working  at  a  profit. 

A  scarcity  of  brimstone  has  led  to  greater  atten- 
tion being  paid  to  native  pyrites,  especially  for  the 
manufacture  of  sulphuric  acid.  While  there  are 
many  deposits  of  iron  pyrites  in  most  parts  of  the 
world,  they  are  not  always  accessible  to  mining  at 
a  low  cost,  and  situated  so  that  transportation  of 
the  low-valued  product  is  easy  and  cheap.  These 
primary  conditions  are  essential  to  the  industrial 
usefulness  of  any  pyrites  bed.  The  production  of 
pyrites  on  a  commercial  scale  in  the  United  States 
is  at  present  confined  to  Massachusetts  and  Virginia. 


As  a  rapid  and  accurate  method  of  estimating  the 
sulphur  available  to  the  acid  maker  in  a  sample  of 
pyrites,  J.  Cuthbert  Welch  has  published  the  fol- 
lowing in  the  Analyst :  Place  5  grammes  of  pyrites 
in  a  porcelain  boat  in  a  combustion  tube,  heat  to 
redness,  pass  oxygen*  over  till  combustion  is  com- 
plete, and  absorb  the  gas  formed  in  about  30  cubic 
centimeters  of  a  solution  of  bromine  in  a  mixture  of 
equal  parts  of  hydrochloric  acid  (specific  gravity 
1.1)  and  water,  in  potash  (or  preferably  nitrogen) 
bulbs.  Wash  out  the  solution  into  a  beaker,  boil, 
precipitate  by  boiling  solution  of  barium  chloride, 
cool,  filter,  and  wash,  dry  and  ignite  the  barium 
sulphate. 

Talc  or  Soapstone,  called  Steatite  when  mas- 
sive, is  a  hydrated  silicate  of  magnesia,  from  which 
the  water  is  only  driven  off  at  a  high  temperature. 
It  usually  occurs  in  foliated  laminar  masses,  like 
mica,  but  differs  from  the  latter  in  not  being  elastic, 
in  being  softer  and  readily  marked  by  the  nail,  in 
yielding  an  unctuous  feeling  powder  and  in  not 
containing  alumina  as  an  essential  ingredient.  The 
laminated  variety  of  talc  has  been  adopted  by  min- 
eralogists as  representing  1  in  the  scale  of  hardness  ; 
its  specific  gravity  is  2.7.     The  color  is  white,  some- 

*  The  oxygen  should  be  prepared  from  pure  potassium  chlorate 
in  glass  vessels,  or  at  any  rate  in  an  iron  one,  kept  especially  for  the 
purpose,  and  the  gas  should  be  passed  through  a  strong  solution  of 
potash  in  the  bulbs,  through  a  U-tube  containing  calcium  chloride, 
and  lastly  either  through  another  calcium  chloride  tube  or,  prefer- 
ably, over  phosphoric  anhydride  before  use. 


VARIOUS    USEFUL    MINERALS.  251 

times  tinged  with  green,  and  the  lustre  pearly. 
When  heated  in  a  matrass,  it  undergoes  no  appre- 
ciable loss  of  water  or  transparency  ;  when  subjected 
to  a  high  heat  it  exfoliates  and  hardens,  but  does 
not  melt.  Acids  have  no  effect  upon  it,  either  after 
or  before  ignition.  Talc  is  quarried  and  employed 
for  various  purposes.  It  is  mixed  with  clay  to  in- 
crease the  translucency  of  the  finished  porcelain  ; 
when  powdered  it  is  used  for  diminishing  the  fric- 
tion of  machinery,  and  as  a  basis  for  colored  cos- 
metic powders.  Pencils  are  made  from  it  for  remov- 
ing grease  from  silks  and  cloths,  and  for  marking 
out  the  paterns  of  clothes. 


CHAPTER  XIV. 

PETROLEUM,  OZOCERITE,  ASPHALT,  PEAT. 

Crude  petroleum  occurs  only  in  the  higher 
strata  of  rocks,  it  being  never  found  in  metamorphic 
rocks  or  crystalline  formation.  The  Pennsylvania 
oil  strata  belong  to  the  Devonian  age,  the  anticlinal 
ridges  being  more  favorable,  it  is  said,  than  the 
synclinal  ones.  In  Kentucky  it  occurs  near  the 
base  of  carboniferous  limestone.  In  California  it  is 
found  in  strata  belonging  to  the  tertiary  age,  in 
Colorado  and  other  western  States,  in  those  belong- 
ing to  the  cretaceous,  and  in  North  Carolina  in 
those  belonging  to  the  triassic.  In  West  Virginia 
it  occurs  in  strata  belonging  to  the  coal  measures. 
Crude  petroleum  is  a  fluid  of  a  dark  color,  sometimes 
black,  and  contains  84  to  88  per  cent,  of  carbon,  the 
rest  hydrogen. 

In  prospecting  for  petroleum,  the  prospector,  be- 
sides the  customary  outfit,  should  carry  a  stick  pro- 
vided with  a  long  iron  point.  It  is  best  to  follow 
the  courses  of  rivers  and  creeks  upward,  because  the 
progress  of  the  work  will  not  then  be  impeded  by 
the  turbidity  of  the  water.  It  is  also  advisable  to 
make  such  excursions  in  the  warm  season  of  the 
year,  because  the  oil  exudes  more  freely  at  that  time 
(252) 


PETROLEUM,  OZOCERITE,  ASPHALT,  PEAT.         253 

than  in  cooler  weather,  when  especially  heavy  oils 
and  mineral  tar,  or  maltha,  are  readily  converted 
into  a  butyraceous  mass.  It  is  also  best  to  wait 
until  the  water  in  the  rivers  and  creeks  is  low. 

Observe  whether  the  surface  of  the  water  exhibits 
variegated  iridescent  figures,  this  being  especially 
the  case  in  places  where  the  water  stands  quietly  or 
moves  very  little,  for  instance,  in  coves.  Such  an 
iridescent  film,  when  found,  may  be  due  to  petro- 
leum, but  also  to  iron  oxides  and  similar  substances. 
However,  by  touching  the  surface  of  the  water,  for 
instance,  with  the  iron-pointed  stick,  a  film  of  oxide 
of  iron  may  be  disintegrated  in  angular  pieces  and 
very  small  flakes,  which  can  be  moved  in  any  direc- 
tion, while  oil  films,  when  separated,  reunite,  and 
can  be  readily  distinguished  from  allied  indications 
by  the  many  changes  in  color  and  figures.  To  be 
sure,  films  of  very  heavy  oil  may  occasionally  be 
met  with  which  can  be  separated  into  angular  pieces, 
behaving  in  this  respect  like  iron  oxides,  but  they 
almost  invariably  exhibit  variegated  movable  rings 
of  color.  In  swamps  other  substances  may  produce 
a  phenomenon  similar  to  crude  oil. 

When  indications  of  oil  have  in  this  manner  been 
discovered  in  a  quiet  part  of  a  water-course,  try  to 
remove  the  iridescent  film  of  the  water  course  and 
turn  up  the  bottom  by  several  times  driving  the 
iron-pointed  stick  into  it.  If  films  of  oil  together 
with  bubbles  of  gas  reappear,  and  this  phenomenon 
occurs  regularly  after  repeated  experiments,  there 
may  be  an  outcrop  of  oil  which  deserves  further 
examination. 


254        PROSPECTORS    FIELD-BOOK    AND    GUIDE. 

However,  if  the  work  with,  the  iron-pointed  stick 
yields  negative  results,  the  oil  must  have  floated 
down  from  above,  and  the  examination  of  the  water 
course  has  to  be  continued  until  by  means  of  the 
iron-pointed  stick  the  source  of  the  traces  of  crude 
oil  has  been  found.  This  source  will  usually  be  in 
sandstone  or  other  porous  rock,  and  pieces  knocked 
off  with  a  hammer  will  exhibit  the  oil  generally  in 
the  form  of  drops,  partly  upon  the  surfaces  of  the 
strata  and  partly  also  in  small  cavities.  Instead  of 
petroleum,  mineral  tar — a  black,  smeary  mass — 
will  frequently  be  found. 

The  rock  itself  is  occasionally  impregnated,  which 
may  be  recognized  partly  by  the  odor  and  partly  by 
the  so-called  water-test  For  this  purpose  place  a 
piece  of  the  rock  in  quiet  water,  if  possible  exposed 
to  the  rays  of  the  sun  ;  if  the  rock  contains  oil  the 
characteristic  iridescent  colors  appear,  as  a  rule, 
immediately  upon  the  surface  of  the  water. 

The  fresh  fracture  of  oil-bearing  sandstone  is,  as 
a  rule,  of  a  darker  color  than  that  of  adjoining  rock. 
After  rain,  drops  of  water  adhere  to  out-crops  of  oil 
sandstone  in  a  manner  similar  to  that  observed  on 
other  fatty  substances. 

If  in  prospecting  in  water-courses  oil-bearing 
sandstone  has  been  found,  the  question  has  to  be 
answered  whether  the  prospector  has  to  deal  with 
contiguous  rock  or  simply  with  an  erratic  block. 
This  question  can,  as  a  rule,  be  decided  without 
much  difficulty,  from  the  position  of  the  stratifica- 
tion and  the  petrographic  character  of  the  rock  in 


PETROLEUM,  OZOCERITE,  ASPHALT,  PEAT.         255 

question  as  compared  with  the  surroundings.  How- 
ever, if  there  is  still  a  doubt,  examine,  by  means  of 
the  water-test,  the  portions  of  rock  in  the  natural 
continuation  of  the  block. 

Should  the  oil-bearing  rock  actually  turn  out  to 
be  an  erratic  block,  the  rock  from  which  it  has  been 
derived  will  be  found  above,  either  on  the  slopes  or 
in  the  water-course  itself.  Knowing  the  petro- 
graphic  character  of  the  oil-bearing  block,  it  will 
not  be  difficult  to  find  in  the  neighborhood  the  rock 
from  which  it  is  derived.  In  the  above-described 
manner  the  water-courses  are  traced  to  the  limits 
of  the  territory.  In  carrying  on  the  work  of  pros- 
pecting, it  is  advisable  to  examine  specimens  of  all 
the  sandstone  by  means  of  the  water-test,  since  the 
latter  frequently  shows  the  presence  of  petroleum, 
though  there  may  be  no  external  indications  of  it. 

It  may  be  mentioned,  that  in  cooler  weather  the 
traces  of  oil  upon  the  surface  of  the  water  do  not 
yield  blue,  red,  yellow,  etc.,  figures,  or  at  least  not 
very  vivid  ones,  but  a  milky  coloration,  which 
possibly  may  also  be  due  to  other  causes,  so  that 
determination  is  more  difficult  and  less  certain. 
This  is  another  reason  why  it  is  advisable  to  select 
warm  days  for  prospecting.  That  oil  may  also  be 
detected  by  its  odor  need  scarcely  be  mentioned. 

In  swampy  puddles  iridescent  films,  which  do  not 
consist  of  iron  oxides,  but  of  hydrocarbons  formed 
by  decomposition,  are  occasionally  met  with.  If  due 
to  the  latter  cause,  they  do  not  reappear,  or  at  least 
only  to  a  slight  extent,  when  removed  with  the  iron- 


256      prospector's  field-book  and  guide. 

pointed  stick  from  the  surface  of  the  water.  How- 
ever, in  examining  the  bottom,  gas-bubbles  gener- 
ally rise  to  the  surface.  Such  puddles  are  examined 
first  in  the  centre,  and  then  by  detaching  pieces 
from  the  edges  with  the  iron-pointed  stick. 

Salses  (mud-volcanoes),  as  well  as  abundant  ex- 
halations of  natural  gas,  if  not  derived  from  coal 
measures,  are  promising  indications  of  the  presence 
of  petroleum  in  the  territory. 

It  need  scarcely  be  mentioned  that  porous  rock — 
if  oil-bearing — justifies  greater  expectations  than 
compact  rock,  and  that  larger  quantities  of  oil  may 
be  looked  for  in  oil-bearing  sandstones  of  greater 
thickness. 

Although,  generally  speaking,  a  rich  occurrence 
of  oil  may  be  inferred  from  abundant  indications  in 
the  outcrop,  the  reverse  is  not  always  correct ;  in 
many  oil-fields,  now  productive,  the  indications 
when  first  found  were  not  especially  encouraging. 

If  the  oil  occurs  in  definite  geological  horizons, 
the  latter  must  be  particularly  searched  for  and 
traced  and  carefully  examined  in  the  water-courses 
crossing  them,  not  only  because  the  strata  are  there 
most  denuded  so  as  to  allow  of  the  best  view  of  their 
geological  structure,  but  also  because  the  oil,  since 
the  restraining  covering  is  wanting,  has  the  best 
chance  of  exuding  there,  and  the  cut  of  the  water- 
course is  generally  one  of  the  lowest  points  of  the 
outcrop,  where  the  most  abundant  exudation  takes 
place  in  consequence  of  the  greater  head  of  pressure. 

A   very  important   question  is  whether  the  oil 


PETKOLEUM,  OZOCERITE,  ASPHALT,  PEAT.         257 

occurs  in  beds  or  in  veins.  In  answering  this  ques- 
tion the  following  particulars  may  serve  as  guiding 
points : 

With  proportionately  greater  denudation  of  the 
oil-bearing  rock,  it  is  sometimes  possible  directly  to 
decide  this  question  by  observation,  whereby  the 
prospector,  however,  must  take  into  consideration 
that  even  with  a  bed-like  occurrence  the  oil  will 
collect  in  small  fissures.  With  a  vein-like  occur- 
rence a  fissure  may  be  traced  to  where  it  assumes 
larger  dimensions  in  the  strike  and  dip. 

If  the  prospector  has  to  deal  with  a  thick  seam  or 
stratum  of  sandstone,  recognized  as  oil-bearing,  im- 
bedded in  another  rock,  for  instance,  shale,  such 
seam  should  be  traced  and  pieces  freshly  cut  from  it 
examined  as  to  their  content  of  oil  by  the  water-test. 
If  positive  results  are  obtained,  it  may  be  inferred 
that  the  sandstone  is  the  bearer  of  the  oil,  and  that 
it  is  a  bed-like  occurrence. 

In  a  large  mass  of  sandstone  several  outcrops  of 
oil  may  sometimes  be  found  at  quite  a  distance 
from  each  other.  If  in  tracing  the  stratum  of  the 
first  outcrop  according  to  its  strike,  the  second, 
third,  etc.,  outcrops  are  encountered,  we  have  to  do 
with  a  bed-like  occurrence.  This  tracing  of  the 
stratum  is  effected  by  means  of  a  compass,  however, 
always  with  due  consideration  to  the  configuration 
of  the  ground.  Suppose  the  cross-section  of  the 
sandstone  bed  with  the  declivity — the  so-called  out- 
crop-line— construed  and  traced.  The  outcrop-line 
will  deviate  the  more  from  the  straight  line  of 
17 


258      prospector's  field-book  and  guide. 

strike,  the  flatter  the  strata  and  declivities  lie.  In 
tracing  the  same  stratum,  it  must  be  observed 
whether  its  strike  does  not  change,  which,  of  course, 
will  necessitate  a  change  in  the  route  of  the  pros- 
pector. 

If  some  promising  outcrops  of  oil  have  been  found, 
which  will  justify  the  execution  of  more  extensive 
and  more  expensive  prospecting  work,  it  is  advis- 
able to  mark  accurately  in  the  sketch-map,  in  addi- 
tion to  the  outcrops,  the  relative  heights,  generally 
determined  by  an  aneroid  barometer,  the  strike  and 
dip  of  the  stratum  reduced  to  the  astronomical 
meridian,  and  the  outcrops  of  well  characterized 
concordant  strata,  for  instance,  imbedded  shale,  S, 
Fig.  61,  no  matter  whether  they  lie  in  the  upcast  or 
downcast  of  the  outcrops  of  oil,  a.  The  relative 
heights  of  one  of  these  strata  are  determined  in 
several  places,  selecting  points  which  can  be  readily 
found  upon  the  map,  and,  if  possible,  lie  at  the  same 
height,  which  can  be  readily  effected  without  essen- 
tial error  with  the  assistance  of  an  aneroid  barome- 
ter by  taking  observations  in  rapid  succession.  The 
points  of  same  height,  for  instance,  1  and  2,  give 
the  strike  of  the  stratum  for  a  greater  distance. 

By  connecting  the  outcrops  of  oil  a  by  a  line  AA, 
and  again  determining  in  the  latter  several  points 
of  the  same  height,  for  instance,  3,  4  and  5,  the 
general  strike  is  again  obtained.  If  the  latter  runs 
parallel  with  the  general  strike  of  the  characteristic 
stratum  S,  previously  traced,  one  is  justified  in  in- 
ferring a  bed-like  occurrence  of  oil,  even  if  the  con- 


PETROLEUM,  OZOCERITE,  ASPHALT,  PEAT.         259 

strued  dip  of  the  outcrop  line  of  oil    corresponds 
with  the  observed  local  dip  of  the  strata. 

In  these  investigations  it  is  presupposed  that  the 
oil  is  recognized  as  exuding  from  the  solid  rock,  an 
error  regarding  the  outcrop  of  it  being,  therefore, 

Fig.  61. 


excluded.  Such  an  error  may,  however,  occur  when 
the  outcrop  is  covered  with  loose  masses  of  earth 
and  rock,  to  the  base  of  which  the  oil  exuding 
above  flows  down  hidden,  and  escapes  further  below 
by  some  accidental  cause. 

A  vein-like  occurrence  of  oil  will  not  show  the 


260 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


above-mentioned  conformities  with  the  characteristic 
concordant  strata.  Such  an  occurrence  presupposes 
a  fissure,  which  is  generally  connected  with  a  throw 
of  the  strata.  This  is  most  frequently  established 
by  the  fact  that  a  characteristic  stratum  suddenly 
ends  and  does  not  reappear  in  its  natural  continua- 
tion, but  either  to  the  right  or  left,  or  higher  or 
lower.     If  two  or  more  such  points  of  disturbance 

Fig.  62. 


have  been  found,  their  connecting  line  is  the  out- 
crop line  of  the  fissure,  Fig.  62.  If  this  line  passes 
through  the  outcrop  a,  or  if  several  outcrops  lie  in 
it,  a  vein-like  occurrence  of  oil  must  be  inferred. 

However,  sometimes  the  oil  occurs  in  a  maze  of 
smaller  and  larger  fissures.  This  is  shown  in  the 
construction  by  the  fact  that  in  the  presence  of  sev- 
eral outcrops  a  linear  distribution  of  the  same  can- 
not be  recognized,  and  that  the  combinations  yield 


PETROLEUM,  OZOCERITE,  ASPHALT,  PEAT.    261 

the  most  varying  results,  according  to  whether  ex- 
ploration is  carried  on  from  the  one  or  the  other 
outcrop.  Such  occurrence  presents  uncommon  dif- 
ficulties in  prospecting. 

It  need  scarcely  be  mentioned  that  in  prospecting 
for  oil,  it  is  of  great  importance  to  hunt  up  and  map 
the  anticlinals  and  their  saddles,  as  well  as  faults. 

The  directions  here  given  for  prospecting  may 
have  to  be  modified  according  to  local  conditions. 
With  a  sufficient  preliminary  knowledge  of  geology, 
any  difficulties  will,  as  a  rule,  be  readily  overcome 
by  thoroughly  digesting  the  principles  of  the  direc- 
tions given. 

As  regards  the  quality  of  the  surface  oil,  it  must 
be  remembered  that  it  is  not  a  criterion  for  the  oil 
occurring  at  greater  depth.  The  oil  thickens  on 
the  surface  of  the  earth,  and  with  increasing  density 
becomes  viscous  and  dark.  If  pale,  limpid,  and 
specifically  lighter  oil  is  found  at  the  outcrop,  it  is 
sure  evidence  of  oil  of  excellent  quality  at  greater 
depth.  In  every  case  it  may  be  expected  that  the 
quality  of  the  oil  at  greater  depth  is  superior  to  that 
at  the  outcrop. 

Ozocerite  is  a  mineral  paraffine  or  wax,  and 
occurs  generally  in  fissures  and  cavities  in  the 
neighborhood  of  coal-fields  and  deposits  of  rock  salt, 
or  under  sandstone  pervaded  with  bitumen.  It  is 
found  in  various  localities  in  Africa,  America,  Asia 
and  Europe.  In  the  United  States  it  occurs  in 
Arizona,  Texas  and  Utah. 

The  most  interesting  deposit  is  in  East  Galicia, 


262 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


The  ozocerite  occurs  there  in  a  saliferous  clay  be- 
longing to  the  miocene  of  the  more  recent  tertiary 
period,  and  forming  a  narrow,  almost  continuous 
strip  on  the  northern  edge  of  the  Carpathian  Moun- 
tains. This  miocene  group  of  saliferous  clay  con- 
sists chiefly  of  bluish  and  variegated  clays,  sands 
and  sandstones,  with  numerous  occurrences  of  gyp- 
sum, rock  salt  and  salt  springs.  In  Boryslaw,  the 
strata  of  saliferous  clay  form  a  perceptible  saddle  as 

Fig.  63. 


of Ozo&erc'te 


they  sink  on  the  south  below  the  so-called  menilite 
slates,  which  are  very  bituminous  and  foliated,  and 
form  here  the  most  northern  edge  of  the  Carpathian 
Mountains.  The  principal  deposit  of  ozocerite  con- 
verges with  the  axis  of  this  saddle  as  shown  in  Fig. 
63,  8  being  the  strata  of  saliferous  clay,  and  M 
menilite  slate. 

Closely  allied  to  ozocerite  are  the  following  min- 
eral resins  : 


PETROLEUM,  OZOCERITE,  ASPHALT,  PEAT.         263 

Retinite,  generally  of  a  yellowish-brown,  some- 
times of  a  green-yellow  or  red  color.  It  is  found 
with  brown  coal  in  various  localities. 

Elaterite  or  elastic  bitumen,  of  a  blackish 
brown  color,  subtranslucent,  and  occurring  in  soft, 
flexible  masses  in  the  lead-veins  of  Castleton,  in 
Derbyshire,  in  the  bituminous  sandstone  of  Wood- 
bury, Connecticut,  etc. 

Pyropissite  occurs  in  strata  in  brown  coal. 

Ozocerite  occurs  in  various  shades  of  color,  from 
pale  yellow  to  black  ;  when  melted  it  generally 
shows  a  dark-green  color.  The  pale  varieties  are 
chiefly  found  in  places  containing  much  marsh  gas. 
The  dark-green,  heavy  variety  is  the  best,  while  the 
black  kind,  or  asphaltic  wax,  is  the  poorest ;  it  con- 
tains resinous  combinations  of  oxygen,  and  is  inter- 
mediate between  mineral  oil  and  ozocerite. 

The  odor  of  ozocerite  is,  according  to  its  purity, 
agreeably  wax-like.  In  consistency  it  is  soft,  pli- 
able, flexible  to  hard  ;  the  mass  in  the  latter  case 
showing  a  conchoidal  fracture,  but  softens  on 
kneading.  The  boiling  point  lies  between  133° 
and  165°  F.,  and  of  the  so-called  "  marble  wax" 
even  as  high  as  230°  F.  The  specific  gravity  is 
from  0.845  to  0.930. 

Ozocerite  is  readily  soluble  in  oil  of  turpentine, 
petroleum,  benzine,  etc.,  and  with  difficulty  in 
alcohol  and  ether ;  it  burns  with  a  bright  flame, 
generally  leaving  no  residue.  Its  elementary  com- 
position is  about  that  of  petroleum,  85  per  cent,  of 
carbon  and  15  per  cent,  of  hydrogen. 


264      prospector's  field-book  and  guide. 

Native  Asphalt  or  Bitumen  is  solid  at  the  ordi- 
nary temperature,  of  a  black  to  blackish-brown 
color  and  a  conchoidal  fracture  with  glossy  lustre. 
Hardness  1  to  2 ;  specific  gravity  1  to  2.  It  melts 
at  90°  F.,  and  is  very  inflammable.  It  appears  to 
be  formed  by  the  oxidation  of  the  non-saturated 
hydrocarbides  in  petroleum.  The  most  remarkable 
deposits  are  in  Cuba,  Trinidad,  and  Venezuela. 
Other  noted  localities  are  the  Dead  Sea,  Seyssel 
(France),  Limmer,  the  Abruzzo,  and  Val  de  Travers. 
It  occurs  also  of  every  degree  of  consistence,  and  in 
immense  quantity,  along  the  coast  of  the  Gulf  of 
Mexico,  chiefly  in  the  States  of  Tamaulipas,  Vera 
Cruz  and  Tabasco,  where  not  unfrequently  it  is  as- 
sociated with  rock  salt  and  "saltpetre."  It  also 
occurs  in  Utah  in  widely  separated  places.  It  has 
been  found  associated  with  ozocerite  and  more  ex- 
tensively as  melted  out  of  sandstone.  California 
includes  a  large  area  which  furnishes  asphalt,  much 
the  larger  proportion  being  the  product  of  the  de- 
composition of  petroleum,  while  the  remainder 
occurs  in  veins  that  are  evidently  eruptive,  the  for- 
mer occurring  in  beds  of  greater  or  less  extent  on 
hill-sides  or  gulch  slopes,  below  springs  of  more 
fluid  bitumen.  These  deposits  are  scattered  over 
the  country  between  the  bay  of  Monterey  and  San 
Diego,  but  are  chiefly  observed  west  and  south  of 
the  coast  ranges,  between  Santa  Barbara  and  the 
Soledad  pass.  Asphalt  occurs  also  in  other  localities 
in  the  United  States,  for  instance  in  Connecticut,  in 
thin  seams  and  veins  in  eruptive  rock  ;  in  New 


PETROLEUM,  OZOCERITE,  ASPHALT,  PEAT.         265 

York  in  the  region  of  eruptive  and  metamorphic 
rocks,  in  Tennessee  in  the  Trenton  limestone,  etc. 
In  some  American  specimens  sulphur  has  been 
found  to  the  extent  of  10.85  per  cent.  Asphalt  is 
in  great  request  for  paving  purposes ;  it  is  of  in- 
creasing value,  and  deposits  are  eagerly  sought  for. 

Peat.  Peat  is  not  a  mineral,  but  consists  of  the 
cumulatively  resolved  fibrous  parts  of  certain  mosses 
and  graminacese.  It  gradually  darkens  from  brown 
to  black  with  increasing  age.  It  occurs  in  beds  or 
in  bogs.  As  a  fuel  it  is  most  economically  used  at 
the  place  where  it  is  grown.  Good  peat  yields  about 
3  to  6  per  cent,  of  tar  proper,  which  is  comparatively 
easy  to  purify  by  the  usual  method. 

The  examination  of  a  peat  bog  is  very  instructive 
with  reference  to  the  formation  of  coal  as  affording 
examples  of  vegetable  matter  in  every  stage  of  de- 
composition, from  that  in  which  the  organized 
structure  is  still  clearly  visible  to  the  black  carbon- 
aceous mass  which  only  requires  consolidation  by 
pressure  in  order  to  resemble  a  true  coal. 


CHAPTER  XV. 

GEMS    AND    PRECIOUS    STONES. 

Although  many  varieties  of  gems  and  precious 
stones  are  known  to  occur  in  the  United  States, 
systematic  mining  for  them  is  carried  on  only  at  a 
few  places,  and  the  annual  output  is  still  very  small 
in  comparison  with  the  prospective  extent  of  the 
field.  Not  many  persons  are  familiar  with  the  ap- 
pearance of  gem  stones  in  their  native  state,  so  that 
while  quartz  pebbles  are  often  mistaken  for  rough 
diamonds,  garnets  for  rubies,  ilmenite  for  black 
diamonds,  etc.,  on  the  other  hand  it  is  quite  proba- 
ble that  many  valuable  occurrences  have  escaped 
notice. 

Many  of  the  gems  are  of  comparatively  little 
value,  so  that  it  is  not  always  profitable  to  pay 
much  attention  to  their  discovery  unless  the  quan- 
tity of  them  is  great,  for  the  cost  of  polishing  is  an 
important  factor  in  assigning  a  value  to  them. 
Many  colored  transparent  and  translucent  kinds  of 
quartz  colored  by  metallic  oxides  fall  under  this 
category.  But  it  is  so  easy  to  prospect  a  stream,  for 
instance,  in  a  country  of  crystalline,  plutonic,  or 
metamorphic  rocks,  that  a  search  for  precious  stones 
and  gems  of  all  kinds  should  be  made  much  more 
frequently  than  is  usually  the  case.  With  regard  to 
(266) 


GEMS    AND    PRECIOUS    STONES.  267 

the  precious  varieties,  it  is  well  to  bear  in  mind  that 
the  valuable  specimens  may  be  associated  with  all 
sorts  of  worthless  specimens,  all  of  which,  though 
impure  in  quality,  may  really  be  sapphires,  spinels, 
chrysoberyls,  tourmalines,  zircons,  etc. 

Though  many  are  translucent  rather  than  trans- 
parent, many  dark  in  outward  appearance,  and  all 
water-worn,  more  or  less,  and  with  surfaces  not  at 
all  glass-like,  and  the  majority  not  apparently  trans- 
parent or  translucent  unless  held  up  to  the  light,  yet 
here  and  there  a  good  specimen  may  be  found. 
For  all  that,  a  knowledge  of  the  general  appearance 
of  such  impure  specimens  is  probably  of  as  much 
importance  as  that  of  the  good  ones,  for  the  pros- 
pector who  comes  across  them  has  an  encouragement 
in  his  search  for  valuable  ones. 

For  some  reason  or  other,  diamonds  and  gold  are 
often  found  in  the  same  alluvial  deposit,  and  aurif- 
erous beds  should  therefore  be  examined  for  the 
precious  stone.  The  specific  gravity  of  the  diamond 
— higher  than  that  of  quartz  or  most  pebbles — and 
that  of  gold  are  so  very  different  that  it  does  not 
follow  that,  for  instance  in  a  stream  bed,  these  two 
minerals  are  always  found  close  together. 

Whilst  certain  characteristics  of  precious  stones, 
such  as  hardness  and  specific  gravity,  given  in  the 
table  later  on,  may  be  useful  to  the  prospector,  yet 
it  is  not  always  an  easy  matter  to  distinguish  a  cer- 
tain precious  stone  from  one  which  may  be  similar 
in  appearance  though  perhaps  of  much  less  value. 
To  assist  any  one  in  doubt,  and  in  many  instances 


268      prospector's  field-book  and  guide. 

to  settle  the  point,  the  diehroiscope,  Figs.  64  and  65, 
is  very  useful,  taking  for  granted  that  some  practice 
with  the  various  kinds  of  translucent  or  transparent 

Fig.  64. 


EXAMINING  A   GEM  THROUGH  THE  DICHROISCOPE. 

stones  of  various  shades  and  colors  has  been   ac- 
quired.   The  diehroiscope  is  in  the  shape  of  a  cylin- 

Fig.  65. 


When  a  transparent  or  semi-transparent  stone  is  examined  through  the 
diehroiscope,  the  color  of  the  square  A  is  different  or  of  a  different  shade  to 
that  of  the  square  B  when  dichroism  exists. 

der  2  inches  long  and  1  inch  in  diameter,  and  thus 
easily  carried  about.. 

Placing  by  means  of  tweezers  a  translucent  or 
transparent  stone  close  to  the  one  end  of  the  instru- 


GEMS    AND    PRECIOUS    STONES.  269 

ment  where  the  two  square  images  are  seen  when 
the  instrument,  held  skywards,  is  looked  into,  and 
turning  it  about  in  various  directions,  and  at  the 
same  time  turning  the  instrument  round,  the  ob- 
server will  notice  whether  the  color  of  the  two 
squares  is  one  and  the  same.  If  the  stone  is  amor- 
phous, such  as  flint,  obsidian,  etc.,  or  crystallizing 
according  to  the  cubic  system,  such  as  diamond, 
spinel  ruby,  garnet,  etc.,  the  two  squares  will  be  of 
the  same  color  to  that  of  the  other  when  the  colored 
stone  is  examined  in  certain  directions,  though  it 
may  be  the  same  in  certain  others. 

Thus  a  true  ruby,  which  affords  two  shades  of 
pink,  can  be  distinguished  from  a  spinel  ruby  or 
garnet  without  dechroism,  or  from  a  pink  tourma- 
line, which  gives  two  colors  but  somewhat  differ- 
ently to  those  of  ruby  ;  so,  too,  a  sapphire,  which 
gives  a  blue  shade  in  one  square,  and  a  light  shade 
of  color  without  any  shade  of  blue  in  the  other,  can 
be  distinguished  from  an  amethyst,  which  affords 
two  shades  of  purple,  or  from  a  blue  spinel,  which 
does  not  show  any  twin  coloration,  or  from  an  iolite 
(or  water  sapphire),  in  which  the  coloration  is  of  its 
own  kind. 

A  tourmaline,  either  the  green  or  brown  variety, 
can  be  recognized  directly  by  the  color  of  the  one 
square  being  quite  dark  compared  to  that  of  the 
other. 

An  emerald  affords  two  distinct  shades  of  green 
(one  bluish),  easily  remembered,  so  a  green  garnet, 
which  does  not  show  twin  colorations,  cannot  be 
mistaken  for  it, 


270      prospector's  field-book  and  guide. 

With  the  dichroiscope  and  two  or  three  minerals, 
such  as  the  sapphire,  topaz  and  rock  crystal  to  test 
for  hardness  and  a  little  practice,  and  a  slight 
knowledge  of  the  crystallization  of  minerals  which, 
though  frequently  found  water-worn,  not  uncom- 
monly retain  traces  of  the  original  crystal  edges  and 
faces,  the  prospector  can  examine  his  specimens 
with  a  very  much  easier  mind  than  he  would  with- 
out them.  Frequently  neither  the  hardness  of  a 
gem  stone  nor  its  behavior  before  the  dichroiscope 
is  sufficient  to  enable  its  identity  to  be  reliably 
known.  In  such  a  case  its  specific  gravity  may 
settle  the  question,  but  this  may  require  a  more  ac- 
curate balance  than  the  prospector  may  possess,  and 
the  advice  of  an  expert  may  be  necessary. 

Diamond.  Diamonds  are  usually  met  with  in 
alluvial  soil,  often  on  gold-diggings.  In  some  In- 
dian fields  a  diamond-bearing  conglomerate  occurs 
which  is  made  up  of  rounded  stones  cemented 
together,  and  lies  under  two  layers,  the  top  one 
consisting  of  gravel,  sand  and  loam,  the  bottom 
one  of  thick  clay  and  mud.  In  the  neighborhood 
of  Pannah,  between  Sonar  and  the  Sona  river 
diamonds  are  found  in  ferriferous  pebble  conglom- 
erate and  in  river  alluvium.  The  most  beautiful 
crystallized  specimens  are,  however,  found  on  the 
west  side  of  the  Nalla-Malla  mountains,  near  Ban- 
ganpally,  between  Pennar  and  Kistnah,  in  a  dia- 
mond-bearing layer  between  beds  of  primitive  con- 
glomerate. 

In  Borneo,  the  diamond  is  found  associated  with 


GEMS    AND    PRECIOUS    STONES.  271 

magnetic  iron  ore,  gold  and  platinum,  in  alluvial 
deposits  consisting  of  serpentine  and  quartz  frag- 
ments as  well  as  marl. 

In  Brazil,  the  province  Minas  Geraes  is  rich  in 
diamonds,  the  most  important  occurrence  being  at 
Sao  Joao  do  Barro,  where  they  are  found  in  an  en- 
tirely weathered  talcose  slate.  In  other  parts  of  the 
same  country  the  diamond  is  also  obtained  from  a 
conglomerate  of  white  quartz,  pebbles  and  light 
colored  sand,  sometimes  with  yellow  and  blue 
quartz  and  iron  sand.  In  the  province  of  Bahia 
occurs  a  substance  known  as  carbonado  or  black  dia- 
mond. It  is  an  allotropic  form  of  carbon  closely 
related  to  the  diamond,  and  is  found  in  small  irreg- 
ular crypto-crystalline  masses  of  a  dark  gray  or 
black  color.  Although  its  density  is  not  so  great  as 
that  of  the  diamond,  it  is  very  much  harder ;  in  fact, 
it  is  the  hardest  substance  known.  At  first  it  was 
used  only  in  cutting  diamonds,  but  since  the  inven- 
tion of  the  core-drill  for  boring  in  rocks  it  has  found 
a  greatly  extended  use,  and  is  now  employed  for  the 
so-called  "  diamond  crown  "  of  this  drill.  The  bort 
of  the  South  African  mines  finds  a  similar  industrial 
application,  being  worthless  as  a  gem. 

In  South  Africa  the  diamond  occurs  associated 
chiefly  with  garnet  and  titanic  iron  ore,  as  well  as 
with  quartz  opal,  calcareous  spar,  and  more  rarely 
with  iron  pyrites,  bronzite,  smaragdite  and  vaalite. 
According  to  St.  Meunier  the  South  African  dia- 
mond-bearing sands  are  composed  of  an  exceedingly 
large  number  of  constituents,  eighty  different  vari- 


272 

eties  of  minerals  and  rocks  having  been  found  in 
them.  Of  minerals  occur,  for  instance,  diamond, 
topaz,  garnet,  bronzite,  ilmenite,  quartz,  tremolite, 
asbestus,  wallastonite,  vaalite,  zeolite,  iron  pyrites, 
brown  iron  ore,  calcareous  spar,  opal,  hyalite,  jasper, 
agate,  clay.  Of  rocks  are  found,  serpentine,  eklo- 
gite,  pegmatite  and  talcose  slate.  At  the  Kimberley 
mine,  which  more  or  less  represents  others  in  the 
neighborhood,  the  diamond-bearing  ground  forms  a 
"pipe"  or  "  chimney  "  surrounded  by  formations 
totally  different  from  the  payable  rock.  The  en- 
casing material  is  made  up  of  red  sandy  soil  on  the 
surface,  underneath  which  is  a  layer  of  calcareous 
tufa,  then  yellow  shale,  then  black  shale,  and  below 
this,  hard  igneous  rock.  The  diamond-bearing 
ground  consists  of  "  yellow  ground  "  (really  the  de- 
composed "  blue  ground  "),  which  is  comparatively 
friable ;  and  deeper  down  the  "  blue  ground " 
(hydrous  magnesian  conglomerate),  which  needs 
blasting  by  dynamite.  The  "  blue  ground  "  is  of  a 
dark  bluish  to  a  greenish  gray  color  and  has  a 
more  or  less  greasy  feel.  With  it  are  mixed  por- 
tions of  boulders  of  various  kinds  of  rocks  such  as 
serpentine,  quartzite,  mica-chist,  chlorite-chist, 
gneiss,  granite,  etc.  All  this  "blue  ground"  has 
evidently  been  subjected  to  heat.  The  gems  are  in 
the  matter  which  binds  these  rocks,  not  in  the  rocks 
themselves. 

Diamonds  are  also  found  in  the  Ural,  various 
parts  of  Australia,  New  Zealand  and  in  the  United 
States.     In  the  latter  country  diamonds  have  been 


GEMS    AND    PRECIOUS    STONES.  273 

found  at  a  number  of  localities,  but  never  enough  to 
warrant  any  extended  mining  for  them.  Many  ex- 
perienced geologists  hold  to  the  opinion  that  since  so 
many  associations  of  the  diamond  are  present  in 
North  Carolina  they  have  hopes  of  their  being  found 
there.  The  garnet  districts  of  Arizona  and  New 
Mexico  may  also  be  looked  upon  as  favorable  for 
the  occurrence  of  this  gem.  Of  the  localities  where 
diamonds  have  been  found  in  the  United  States  may 
be  mentioned  :  The  gold  diggings  of  Twitty's  mine 
in  the  itacolumite  region  of  Rutherford  Co.,  North 
Carolina,  1847  ;  further  in  Hall  Co.,  Georgia,  1850, 
in  the  gold  diggings  of  the  south  slopes  of  the 
Alleghany  mountains,  in  Arizona,  and  in  Califor- 
nia, together  with  platinum  in  various  gold  dig- 
gings. Further  at  Dysartville,  McDowell  Co.,  North 
Carolina,  in  Idaho,  San  Juan  Co.,  Colorado,  and 
Cherokee  Flat  and  several  other  localities  in  Butte 
Co.,  California. 

The  natural  surface  of  the  diamond  is  often 
unequal ;  its  sides  are  lined,  somewhat  convex,  and 
generally  appear  dulled,  or  as  they  are  commonly 
called,  rough,  by  the  evident  action  of  fire.  The 
diamond  breaks  regularly  into  four  principal  cleav- 
ages. It  does  not  sparkle  in  the  rough,  and  the 
best  test  is  its  hardness  and  its  becoming  electric, 
when  rubbed  before  polishing.  The  color  of  the 
diamond  varies  through  all  tones  of  the  color-scale, 
from  absolute  colorless  through  all  shades  of  yellow, 
red,  green,  blue  to  intense  black.  Some  colorless 
18 


274      prospector's  field-book  and  guide. 

diamonds  acquire  on  heating  a  reddish  shade,  which 
disappears  on  cooling. 

The  occurrence  of  diamonds  of  different  colors 
affords  a  remarkable  illustration  of  what  has  been 
said  about  the  colors  of  minerals.  As  pure  carbon, 
diamond  is  colorless,  as  are  also  the  microscopic 
diamonds  artificially  produced  by  an  electric  cur- 
rent, but  in  nature  the  stones  are  of  different  colors, 
which  are  imparted  to  them  by  a  very  small  pro- 
portion of  foreign  matter.  The  yellow  and  gray 
tints  decrease  the  value  of  the  diamond,  but  red, 
blue  and  green  varieties,  on  the  contrary,  are  so 
rare,  that  when  diamonds  are  so  colored  their  value 
is  considerably  greater  than  if  perfectly  colorless. 
For  instance,  the  best  blue  diamond  known  is  esti- 
mated at  double  the  calculated  value  of  a  good 
colorless  diamond  of  the  same  size. 

In  Borneo  a  kind  of  black  diamond  is  found 
which  is  very  highly  prized  in  consequence  of  its 
exceptional  lustre  and  rarity.  It  is  even  harder 
than  the  ordinary  diamond. 

The  specific  gravity  of  the  pure  diamond  varies 
from  3.5  to  3.6  ;  that  of  the  black  diamond  is  from 
3.012  to  3.255. 

One  of  the  most  beautiful  qualities  of  the  diamond 
is  its  power  of  refraction  ;  that  of  water  is  0.785  ; 
that  of  the  ruby,  0.739  ;  that  of  the  rock  crystal, 
0.654  ;  that  of  the  diamond,  1.396.  The  refraction 
of  the  diamond  is  single  in  the  entire  crystals  ;  when 
broken  it  possesses  double,  but  imperfect  refraction, 
in  the  thin  layers. 


GEMS    AND    PRECIOUS    STONES. 


275 


The  value  of  the  diamond  is  dependent  on  its 
color,  its  size  and  the  finish  given  to  it  by  working. 
Perfectly   colorless  stones  bring  the  highest  price, 


Fig.  m. 


and  next  stones  with  a  reddish,  greenish  andjbluish 
shade,  which,  however,  are  quite  rare.  Yellowish 
diamonds  are  of  less  value,  the  price  paid  for  them 
being  the  lower  the  more  the  yellow  color  plays  into 
brown, 


276      prospector's  field-book  and  guide. 

Of  the  largest  diamonds  each  has  its  own  name 
and  its  own  history.  Of  these  may  here  be  men- 
tioned the  Koh-i-noor  or  mountain  of  light,  Fig.  66, 
d.  It  weighs  106TV  carats.  The  Orlof,  Fig.  66,  a, 
weighs  194|  carats,  and  is  as  large  as  half  a  pigeon's 
egg  ;  it  adorns  the  sceptre  of  the  Russian  emperor. 
The  Grand  Duke  of  Tuscany  or  Florentine,  Fig.  66, 
b,  is  one  of  the  most  beautiful  diamonds.  It  is  a 
yellow  diamond,  and  weighs  139|  carats.  It  be- 
longs to  the  house  of  Austria.  The  Pitt  or  Regent, 
Fig.  66,  c,  belongs  to  the  French  treasury  and, 
with  the  exception  of  the  Koh-i-noor,  is  the  most 
beautiful  and  most  regular  diamond.  It  weighs 
136|  carats. 

Sapphire.  The  sapphire  is  the  blue  variety  of 
corundum  in  its  purest  crystalline  state.  Its  gen- 
eral composition  is  alumina  92,  silica  5.25,  oxide  of 
iron  1.0.  The  color  most  highly  valued  is  a  highly 
transparent  bright  Prussian  blue.  More  frequently 
the  color  is  a  pale  blue,  passing  by  paler  shades 
into  perfectly  colorless  varieties.  The  paler  varieties 
are  frequently  marked  by  dark  blue  spots  and 
streaks  which  detract  from  their  value.  But  these 
paler  varieties  lose  their  color  when  subjected  to 
great  heat,  a  fact  that  has  sometimes  been  taken 
advantage  of  b}^  unscrupulous  dealers  to  pass  them 
off  as  diamonds. 

The  principal  form  of  the  sapphire  is  an  acute 
rhomboid,  but  it  has  many  modifications  and  va- 
rieties. On  being  broken  it  shows  a  conchoidal 
fracture,  seldom  a  lamellar  appearance.     The  prin- 


GEMS    AND    PRECIOUS    STONES.  277 

cipal  locality  for  sapphires  in  the  United  States  is 
in  the  garnet  districts  near  Helena,  Montana  ;  Santa 
Fe,  New  Mexico ;  southern  Colorado  and  Arizona. 
Here  they  occur  in  the  sand,  associated  with  peri- 
dot, pyrope  and  alinandine  garnet. 

Ruby.  The  ruby  is  the  red  variety  of  corundum 
and  in  composition  varies  from  almost  pure 
alumina  to  a  compound  containing  10  to  20  per 
cent,  of  magnesia,  and  always  about  1  per  cent,  of 
oxide  of  iron.  The  ruby  is  subdivided  into  several 
varieties  according  to  color,  which  in  its  turn  is 
affected  by  mineral  composition,  spinel  ruby  occur- 
ring in  bright  red  or  scarlet  crystals,  rubicelle  of  an 
orange  red  color,  bala  ruby  rose  red,  almandine  ruby 
violet,  chlorospinel  green,  and  pleonast  is  the  name 
given  to  dark  varieties. 

The  crystals  are  usually  small  and  when  not 
defaced  by  friction  they  have  a  brilliant  lustre,  as 
has  also  the  lamellar  structure,  with  natural  joints 
which  it  shows  on  being  broken.  It  exhibits  va- 
rious degrees  of  transparency.  The  color  most 
valued  is  the  intense  blood  red  or  carmine  color  of 
the  spinel  ruby.  When  the  color  is  a  lilac  blue, 
the  specimen  was  formerly  known  as  the  Oriental 
amethyst,  and  was  regarded  as  a  connecting  link  be- 
tween the  ruby  and  the  sapphire.  In  the  United 
States  the  ruby  is  found  in  various  localities,  in 
some  of  which  the  cr}7stals  have  partly  decomposed 
and  show  a  soft  structure  resembling  steatite.  It 
occurs  in  gneissic  and  metamorphic  rocks  and  in 
granular  limestone.  In  Ceylon  it  is  found  with  the 
sapphire  in  the  river  deposits. 


278      prospector's  field-book  and  guide. 

Topaz  is  composed  of  silica,  alumina  and  fluorine. 
It  occurs  in  prismatic  crystals,  sometimes  furrowed 
lengthwise,  variously  terminated,  breaking  easily 
across  with  smooth  brilliant  cleavage.  Transparent 
or  semi-transparent.  White,  yellow,  greenish,  blu- 
ish, pink.  Lustre,  glassy.  Specific  gravity,  3.5. 
Hardness,  8.  Scratches  quartz  ;  is  scratched  by 
sapphire.  Infusible,  but  often  blistered  and  altered 
by  heat.  When  smooth  surfaces  are  rubbed  on 
cloth  they  become  strongly  electric,  and  can  attract 
small  pieces  of  paper,  but  rough  surfaces  do  not 
show  this.  The  brilliant  cleavage  of  topaz  distin- 
guishes it  from  tourmaline  and  other  minerals. 
Topaz  occurs  in  gneiss  or  granite  with  tourmaline, 
mica,  beryl ;  also  cassiterite  or  tin-stone,  apatite, 
fluorite.  The  white  topaz  resembles  the  diamond, 
but  unlike  the  latter  it  can  be  scratched  by  sapphire. 
The  pale  blue  variety  is  of  value  for  cutting  into 
large  stones  for  brooches ;  specimens  are  occasion- 
ally found  of  several  pounds  weight.  Topaz  of  a 
beautiful  sherry  color  occurs  in  Brazil.  Specimens 
of  this  when  heated  become  pink,  when  they  are 
known  as  burnt  topaz.  The  yellow  varieties  are 
cut  as  gems.  Although  not  very  valuable,  they  are 
quite  brilliant  and  look  very  well. 

Topaz  has  been  found  in  Arizona,  New  Mexico, 
and  occasionally  in  southern  California.  In  the 
latter  state,  and  in  Utah  and  Mexico,  it  sometimes 
occurs  in  fine,  clear  crystals  in  volcanic  rocks.  A 
notable  locality,  especially  for  very  large  crystals, 
is  at  Stoneham,  Maine,  and  another  at  Trumbull, 
Connecticut. 


GEMS    AND    PRECIOUS    STONES.  279 

Beryl  or  Emerald  is  composed  of  silica,  alumina, 
and  beryllium  or  glucinum.  It  is  almost  always 
found  in  distinct  crystals,  and  usually  in  forms  easy 
to  recognize.  The  crystals  are  hexagonal  prisms, 
usually  green,  transparent  or  opaque.  Lustre, 
glassy  ;  fracture  uneven  ;  specific  gravity,  2.7  ;  hard- 
ness, 7  to  8  ;  scratches  quartz.  Infusible,  or  nearly 
so,  but  becomes  clouded  by  heating.  Occurs  in 
granite  rocks  with  feldspar  and  quartz.  Valuable 
for  jewelry  when  transparent  and  rich  grass-green 
(emerald)  or  sea-green  (aquamarine).  Emerald  has 
been  found  in  North  Carolina  and  aquamarine  at  a 
number  of  localities  in  the  United  States. 

A  productive  emerald  mine  is  that  of  Muso,  in 
New  Granada,  Mexico.  The  emerald  occurs  in 
veins  and  cavities  in  a  black  limestone  that  contains 
fossil  ammonites.  The  limestone  also  contains 
within  itself  minute  emeralds  and  an  appreciable 
quantity  of  glucina.  When  first  obtained  the  em- 
eralds from  this  mine  are  soft  and  fragile ;  the 
largest  and  finest  emeralds  could  be  reduced  to 
powder  by  squeezing  and  rubbing  them  with  the 
hand.  After  exposure  to  the  air  for  a  little  time 
they  become  hard  and  fit  for  the  jeweler's  use. 

Phenactte  is  a  silicate  of  beryllium  or  glucinum. 
Its  hardness  is  about  the  same  as  topaz  and  its 
specific  gravity  3.4  to  3.6.  It  occurs  in  glassy 
rhombohedral  crystals,  and  its  hardness,  beautiful 
transparency  and  color  make  it  valuable  for  cutting 
as  a  gem,  since  it  is  capable  of  extreme  polish. 
Phenacite  has  been  found  at  Pike's  Peak,  Colorado, 


280      prospector's  field-book  and  guide. 

in  crystals  of  sufficient  size  and  quality  to  furnish 
fair  gems. 

Zircon  is  composed  of  silica  and  zirconia.  It  is 
found  in  square  prisms  terminated  by  pyramids, 
and  in  octahedrons,  but  often  also  in  pebbles  and 
grains.  Transparent  or  opaque.  Wine  or  brown- 
ish red,  gray,  yellow,  white.  Lustre,  glassy  ;  frac- 
ture, usually  irregular,  but  in  one  direction  it  can 
be  split  so  as  to  exhibit  a  smooth  even  cleavage 
face  having  an  adamantine  lustre  like  the  diamond. 
Specific  gravity  4.0  to  5.0  ;  hardness  7.5  ;  scratches 
quartz,  is  scratched  by  topaz.  Infusible ;  the  red 
varieties,  when  heated  before  the  blowpipe,  emit  a 
phosphorescent  light,  and  become  permanently  col- 
orless. Zircon  occurs  in  syenite,  granite,  basalt. 
In  some  regions  it  occurs  in  the  rock  so  abundantly 
that  when  the  rock  has  been  worn  down  by  the 
weather,  it  is  left  unaltered  in  considerable  quanti- 
ties. It  may  then  be  obtained  by  washing  the 
gravel  in  the  manner  of  the  gold  miner.  Clear 
crystals  are  used  in  jewelry,  in  jeweling  watches, 
and  imitation  of  diamond.  It  may  be  distinguished 
from  the  latter  by  its  inferior  hardness,  and  in  not 
becoming  so  readily  electric  by  friction.  Fine 
crystals  are  obtained  in  New  York  and  Canada  ; 
and  good  specimens  also  come  from  North  Carolina 
and  Colorado. 

Garnet  is  composed  of  silica,  alumina,  lime, 
iron,  magnesia,  manganese.  It  is  found  almost 
always  in  distinct  crystals,  and  as  these  crystals  are 
commonly  isolated  and  scattered  through  the  rock, 


GEMS    AND    PRECIOUS    STONES.  281 

it  is  not  difficult  to  recognize  them.  The  crystals 
are  usually  twelve-sided,  having  the  form  of  a 
rhombic  dodecahedron.  They  are  transparent  or 
opaque  ;  generally  red  ;  also  brown,  green,  yellow, 
black,  white.  Lustre,  glassy  or  resinous  ;  fracture 
conchoidal  or  uneven  ;  specific  gravity  3.5  to  4.3  ; 
hardness,  6.5  to  7.5  ;  cannot  be  scratched  with  a 
knife.  Fusible  with  more  or  less  difficulty.  Red 
varieties  impart  a  green  color  to  borax  bead  owing 
to  presence  of  chromium.  Garnet  usually  occurs  in 
crystals  scattered  through  granite,  gneiss  or  mica 
schist,  also  in  crystalline  limestone  ;  with  serpen- 
tine or  chromite;  also  in  some  volcanic  rocks.  Fine 
colored  transparent  varieties  (carbuncle,  cinnamon 
stone,  almandine)  are  used  in  jewelry.  The  garnets 
found  in  New  Mexico  and  Southern  Colorado,  and 
there  called  "  rubies,"  are  as  line  as  those  from  any 
other  locality,  the  blood-red  being  the  most  desir- 
able. Very  fine  crystals  of  cinnamon  stone,  cinna- 
mon garnet  or  essonite  have  been  found  in  New 
Hampshire,  Maine,  and  at  many  other  points  in 
the  United  States. 

Tourmaline  is  composed  of  silica,  alumina,  mag- 
nesia, boracic  acid,  fluorine,  oxides  of  iron  (lime 
and  alkalies).  It  is  found  in  prisms  with  three,  six, 
nine  or  more  sides,  furrowed  lengthwise,  terminat- 
ing in  low  pyramids.  Commonly  black  and  opaque, 
rarely  transparent,  and  of  a  rich  red,  yellow,  or 
green  color.  Lustre  glassy  ;  fracture  uneven  ;  spe- 
cific gravity  3.1  ;  hardness  7  to  8 ;  cannot  be 
scratched  with  a  knife.     When  the  smooth  side  of 


282      prospector's  field-book  and  guide. 

a  prism  is  rubbed  on  cloth  it  becomes  electric  and 
can  attract  a  small  piece  of  paper.  Tourmaline 
occurs  in  granite  and  slate.  Only  the  fine  colored 
transparent  varieties,  which  are  used  as  gems  and 
for  optical  purposes,  are  of  value.  The  principal 
source  of  tourmaline  in  the  United  States  is  the 
locality  Mount  Mica,  at  Paris,  Maine. 

Epidote  is  a  silicate  of  alumina,  iron  and  lime, 
but  varies  rather  widely  in  composition,  especially 
as  regards  the  relative  amounts  of  alumina  and 
iron.  It  is  usually  found  in  prismatic  crystals, 
often  very  slender  and  terminated  at  one  end  only  ; 
they  belong  to  the  monoclinic  system.  Lustre, 
vitreous ;  color,  commonly  green,  although  there 
are  black  and  pink  varieties.  Epidote  is  found  in 
many  localities  in  the  United  States  and  in  very 
large  crystals  ranging  from  brown  to  green  in  color, 
but  as  a  rule  the  crystals  are  only  translucent  or 
semi-opaque,  though  some  stones  of  considerable 
value  and  great  beauty  have  been  found  in  Rabun 
county,  Georgia. 

Opal  is  composed  of  silica  and  water.  It  is  never 
found  in  crystals,  but  only  in  massive  and  amorphous 
form.  Fracture,  conchoidal ;  specific  gravity  2.2  ; 
hardness,  6 ;  can  be  scratched  by  quartz  and  thus 
distinguished  from  it.  It  is  infusible  and  generally 
milk-white.  The  most  beautiful  variety  of  opal  is 
that  called  precious  opal,  which  exhibits  a  beautiful 
play  of  colors  and  is  a  valuable  gem.  One  kind  of 
precious  opal  with  a  bright  red  flash  of  light  is 
called  the  fire  opal,  and  another  kind  is  the  harle- 


GEMS    AND    PRECIOUS    STONES.  283 

quin  opal.  Common  opal  does  not  exhibit  this  play 
of  colors,  and  it  varies  widely  in  color  and  appear- 
ance. Milk  opal,  as  one  variety  is  called,  has  a  pure 
white  color  and  milky  opalescence,  while  resin  opal 
or  wax  opal  has  a  waxy  lustre  .and  yellow  color. 
Jasper  opal  is  intermediate  between  jasper  and  opal ; 
wood  opal  is  petrified  wood,  in  which  the  mineral 
material  is.  opal  instead  of  quartz.  Opal  is  com- 
monly met  with  in  seams  of  certain  volcanic  rocks  ; 
sometimes  it  occurs  in  limestone  and  also  in  metal- 
lic veins.  Precious  opal  is  rare  in  the  United 
States,  though  some  of  high  value  is  said  to  have 
been  found  in  Creek  Co.,  near  John  Davy's  River, 
Oregon. 

Turquois  is  a  hydrated  phosphate  of  aluminium, 
containing  also  a  little  copper  phosphate,  which  is 
probably  the  source  of  the  color,  which  in  the  most 
precious  variety  is  robin's-egg  blue,  and  bluish- 
green  in  less  highly  prized  varieties.  It  occurs  only 
in  compact  massive  forms,  filling  seams  and  cavi- 
ties in  volcanic  rock.  Specific  gravity  3.127.  Tur- 
quois has  been  found  in  the  Holy  Cross  mining 
region,  thirty  miles  from  Leadville,  Colorado,  and 
of  late  years  a  number  of  mines  have  been  opened 
in  New  Mexico,  at  Los  Carillos  and  in  Grant 
County.  The  latter  mines  produce  stones  having  a 
faint  greenish  tinge,  which  is  either  due  to  a  partial 
change  or  metamorphism,  which  has  taken  place 
while  the  turquois  was  in  the  rock,  or  it  may  be  a 
local  peculiarity.  Turquois  occurs  also  in  Arizona 
and  at  a  point  in  Southern  Nevada.     At  the  latter 


284      prospector's  field-book  and  guide. 

place  it  is  found  in  veins  of  small  grains  in  a  hard 
shaly  sandstone.  The  color  of  this  turquois  is  a 
rich  blue,  almost  equal  to  the  finest  Persian,  and 
the  grains  are  so  small  that  the  sandstone  is  cut 
with  the  turquois  in  it,  making  a  rich  mottled  stone 
for  jewelry. 

Agate  is  found  in  almost  every  part  of  the  world, 
and  the  difference  of  the  constituent  parts  makes 
the  specific  gravity  vary  from  2.58  to  2.69.  The 
agate,  properly  so  called,  is  naturally  translucent, 
less  transparent  than  crystalline  quartz,  but  yet 
less  opaque  than  jasper.  It  is  too  hard  to  be  even 
scratched  by  rock  crystal.  It  takes  a  very  good 
polish.  It  is  never  found  in  regular  forms,  but 
always  either  in  nodules,  in  stalactites,  or  in  irregu- 
lar masses.  Eye  agates  consist  of  those  parts  of  the 
stone  in  which  the  cutting  discovers  circular  bands 
of  very  small  diameter  arranged  with  regularity 
round  one  circular  spot.  These  circles  are  fre- 
quently so  perfect  that  they  appear  to  be  traced  by 
the  compass.  The  first  round  is  white,  the  second, 
black,  green,  red,  blue  or  yellow ;  the  most  rare  are 
those  whose  circles  are  at  equal  distance  from  the 
centre.  Moss  agate  contains  brown-black,  moss-like 
or  dendritic  forms  distributed  rather  thickly  through 
the  mass.  These  forms  consist  of  some  metallic 
oxide  (as  of  manganese).  Of  all  the  American 
stones  used  in  jewelry  there  is  no  other  of  which  so 
much  is  sold  as  the  moss  agate.  The  principal 
sources  of  supply  are  Utah,  Colorado,  Montana  and 
Wyoming. 


GEMS    AND    PRECIOUS    STONES.  285 

Chalcedony  is  a  semi-transparent  variety  of 
quartz,  of  a  waxy  lustre  and  varying  in  color  from 
white  through  grey,  green  and  yellow  to  brown. 
It  is  translucent  or  semi-transparent.  It  occurs  in 
stalactite,  reniform  or  botryoidal  masses,  which 
have  been  formed  in  cavities  in  greenstones  and 
others  of  the  older  rocks.  Into  these  cavities,  as 
into  miniature  caverns,  water  holding  silicious 
matter  has  penetrated  and  deposited  its  solid  con- 
tents, consisting  almost  exclusively  of  silica  tinged 
by  the  presence  of  other  minerals.  Some  of  these 
cavities  are  several  feet  in  diameter,  and  besides  the 
coloring  of  the  encircling  mass  there  are  often,  in 
the  interior  of  the  concretions  in  them,  cavities  or 
central  nuclei  which  contain  sometimes  as  many  as 
twenty-four  different  substances,  as  silver,  iron 
pyrites,  rutite,  magnetite,  tremolite,  mica,  tourma- 
line, topaz,  with  water,  naphtha,  and  atmospheric 
air. 

Chrysoprase  is  of  a  beautiful  apple-green  color, 
due  to  oxide  of  nickel.  In  a  warm,  dry  place  the 
color  of  chrysoprase  is  destroyed,  but  it  can  be  again 
restored  by  keeping  it  damp. 

Carnelian  and  Sard  have  red  or  brownish  tints 
and  are  varieties  of  chalcedony. 

Jasper  is  quartz  rendered  opaque  by  clay,  iron 
and  other  impurities.  It  is  of  a  red,  yellow  or  green 
color.  Sometimes  the  colors  are  arranged  in  rib- 
ands, or  in  other  fantastic  forms.  It  is  used  for 
ornamental  work. 

Bloodstone  or  Heliotrope  is  green  jasper,  with 
splashes  of  red  resembling  blood  spots. 


286      prospector's  field-book  and  guide. 

Rock  crystal  is  pure,  transparent,  colorless 
quartz,  and  is  found  at  a  great  many  localities  in 
the  United  States,  In  Herkimer  County,  at  Lake 
George,  and  throughout  the  adjacent  regions  in 
New  York  state,  the  calciferous  sandstone  contains 
single  crystals,  and  at  times  cavities  are  found  filled 
with  doubly  terminated  crystals,  often  of  remarkable 
perfection  and  brilliancy.  These  are  collected,  cut, 
and,  often  uncut,  are  mounted  in  jewelry  and  sold 
under  the  name  of  "  Lake  George  diamonds." 

Amethyst  is  a  transparent  variety  of  quartz  of  a 
rich  violet  or  purple  color  due  to  the  oxide  of  man- 
ganese which  it  contains.  It  crystallizes  in  the  form 
of  a  hexagon,  terminated  at  the  two  heads  by  a 
species  of  cone  with  six  facets.  These  crystals  are 
often  in  masses,  and  the  base  is  always  less  colored 
than  the  top.  Amethysts  are  generally  found  in 
metalliferous  mountains,  and  are  always  in  combi- 
nation with  quartz  and  agate.  They  occur  in  many 
localities  in  the  United  States,  but  not  in  as  fine  or 
large  specimens  as  in  Brazil  or  Siberia. 

Rose  Quartz  is  pink,  red  and  inclining  to  violet- 
blue  in  color.  Occurs  in  fractured  masses  and  is 
imperfectly  transparent.  The  color  is  most  perma- 
nent in  moisture. 

Smoky  Quartz  are  quartz  crystals  tinted  with  a 
smoky  color,  becoming  sometimes  black  and  opaque. 

Yellow  or  Citron  Quartz  or  False  Topaz 
occurs  in  light-yellow  translucent  crystals.  It  is 
often  set  and  sold  for  topaz,  but  it  may  be  distin- 
guished from  it  by  the  absence  of  cleavage. 


GEMS    AND    PRECIOUS    STONES.  287 

Onyx  and  Sardonyx.  A  variety  of  quartz  hav- 
ing a  regular  alternation  of  strata  more  or  less  even, 
and  variously  colored  in  black,  white,  brown,  gray, 
yellow  and  red.  When  the  onyx  has  one  or  two 
strata  of  red  carnelian,  it  is  more  valued  and  takes 
the  name  of  sardonyx.  In  the  onyx  the  dark  strata 
are  always  opaque  and  contrast  strongly  with  the 
clear,  which,  when  thinned,  become  almost  trans- 
lucent. 

Cat's  Eye  consists  of  a  quartz  mixed  with  paral- 
lel fibres  of  asbestus  and  amianthus.  It  is  found  in 
pebbles  and  in  pieces  more  or  less  rounded  :  it  has  a 
concave  fracture ;  is  translucent  and  also  transpar- 
ent at  the  edges.  It  has  a  vitreous  and  resinous 
light.  It  is  generally  either  green,  red,  yellow  or 
gray.  It  marks  glass.  Its  specific  gravity  is  from 
2.56  to  2.73.  When  exposed  to  a  great  heat  it  loses 
lustre  and  transparency,  but  does  not  melt  under 
the  blowpipe  unless  reduced  to  minute  fragments. 

Many  other  gem  stones  are  known  to  occur  in  the 
United  States,  and  the  following  list  compiled  by 
Mr.  George  F.  Kunz  *  is  here  given  : 

*  Mineral  Kesources  of  the  United  States,  Washington,  1883. 


288 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


List  of  gem  stones  known 
Achroite  (tourmaline). 
Agate  (quartz). 
Agatized  wood  (quartz). 
Almandine  (garnet). 
Amazon  stone  (microlene). 
Amber. 

Amethyst  (quartz). 
Aquamarine  (beryl). 
Asteria. 
Beryl. 
Bloodstone. 
Bowenite  (serpentine). 
Cairngorm  (quartz). 
Catlinite. 

Chalcedony  (quartz). 
Chiastolite. 
Chlorastrolite. 
Chondroite. 
Chrysolite. 
Danburite. 
Diamond. 

Diopside  (pyrozene). 
Elpeolite  (nephelite). 
Emerald  (beryl). 
Epidote. 

Essonite  (garnet). 
Fleche  d'amour  (quartz). 
Fluorite. 
Fossil  coral. 
Garnet. 

Grossularite  (garnet). 
Heliotrope. 
Hematite. 

Hiddenite  (spodumene). 
Hornblende  in  quartz. 
Idocrase. 

Indicolite  (tourmaline). 
Iolite. 
Isopyre. 


to  occur  in  the  United  States. 
Jade. 
Jasper. 

Jet  (mineral  coal). 
Labradorite. 

Labrador  spar  (labradorite). 
Lake  George  diamonds  (quartz). 
Lithia  emeralds  (spodumene). 
Made. 
Malachite. 

Moonstone  (feldspar  group). 
Moss  agate  (quartz). 
Novaculite  (quartz). 
Obsidian. 

Olivine  (chrysolite). 
Opalized  wood  (oyal). 
Peridot  (chrysolite). 
Phenakite. 
Prehnite. 
Pyrope  (garnet). 
Quartz. 
Rhodonite. 

Rock  crystal  (quartz). 
Rose  quartz  (quartz). 
Ruby  (corundum). 
Rubellite  (tourmaline). 
Rutile. 

Rutile  in  quartz  (quartz). 
Sagenite  (quartz). 
Sapphire  (corundum). 
Silicified  wood  (quartz). 
Smoky  quartz  (quartz). 
Smoky  topaz  (quartz). 
Spinel. 
Spodumene. 
Sunstone  (feldspar). 
Thetis  hair  stone  (quartz). 
Thomsonite. 
Tourmaline. 
Topaz. 


GEMS    AND    PRECIOUS    STONES. 


289 


Turquois. 

Venus  hair  stone  quartz. 

Willemite. 

Williamsite  (serpentine). 

Wood  agate  (quartz). 


Wood  jasper  (quartz). 

Wood  opal  (opal). 

Zircon. 

Zonochlorite  (prehnite). 


List  of  species  and  varieties  found  in  the   United  States,  but  not  met 
with  in  gem  form. 


Andalusite. 

Axinite. 

Cassiterite. 

Chrysoberyl. 

Cyanite. 


Ilvaite. 

Opal. 

Prase  (quartz). 

Sphene. 

Titanite. 


List  of  species  and  varieties  not  yet  identified  in  any  form  in  the 
United  States. 

Demantoid. 
Euclase. 
Lapislazulite. 
Ouvarite. 


Alexandrite. 
Cat's-eye  chrysoberyl 
Cat's-eye  quartz. 
Chrysoberyl  cat's  eye 
Chrysoprase. 


Quartz  cat's  eye. 


List  of  gem  stones  occurring  only  in  the  United  States. 


Bowenite". 

Chlorastrolite. 

Chondrodite. 

Hiddenite. 

Lithia  emerald. 

Novaculite. 

19 


Kutile. 

Thetis  hair  stone. 

Thompsonite. 

Willemite. 

Williamsite. 

Zonochlorite. 


290      prospector's  field-book  and  guide. 


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GEMS    AND    PRECIOUS    STONES. 


291 


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Right  rhombic  prism,  octa- 
hedral rhombic  prism. 

Hexagonal  prism. 

Long    and     short    square 
prisms.    Long  square  oc- 
tahedron.    The     prisms 
often  doubly  terminated 
with  square  pyramids. 

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rhombic      dodecahedral 
cube,         trapezohedron, 
hexa-octahedron. 

°^    P 

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Rhombic. 

Hexag- 
onal. 

Tetrag- 
onal. 

Cubical. 

Composition. 

Silica,                      34.01 
Alumina,                58.38 
Fluorine,                 15.06 
Traces  of  metallic  ox- 
ides. 
Silica,                      68.50 
Alumina,                 15.75 
Glucina,                  12.50 
Oxide  of  iron,           1.00 
Lime,            •            0.25 

Silica,                      33.0 
Zircoma,          •        66.8 
Peroxide  of  iron,     0.10 

Silica,                      38.25 
Alumina,                 19.35 
Red  oxide  of  iron,   7.33 
Lime,                       31.75 
Magnesia,                 2.40 
Protoxide  of  man-  ' 
ganese,                   0.50 

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Scratches 
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ly- 

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Emerald,  fine  green. 

Beryl  or  Aquamarine,  pale 
sea-green,  blue,  white,  yel- 
low, rarely  pink. 

Hyacinth  or  Zircon,  brown- 
ish-yellow, brownish-red, 
cinnamon. 

Jargon,    various   shades  of 
green, yellow,  white,brown. 
Garnet. 

292 


PROSPECTOR'S    FIELD-BOOK    AND    GUIDE. 


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Name  and  Color 

<1QQ      Ph      H                                   ^h                               Q 

APPENDIX. 

PROSPECTING    BY    MEANS    OF    ELECTRICITY. 

Mr.  Leon  Draft  and  Mr.  Alfred  Williams  have 
invented  a  method  of  finding  ore  by  means  of  elec- 
tricity, by  which  they  claim  to  be  able  to  detect  the 
presence  of  certain  mineral  ores  invisible  to  the  eye 
and  undiscoverable  by  mining  engineering.  It  is 
claimed  that  by  this  method  not  only  can  deposits 
be  located,  but  that  the  extent  and  depth  of  the 
lode  can  be  determined  with  an  accuracy  that  is 
quite  impossible  with  any  existing  system  of  pros- 
pecting. 

In  working  this  method  there  are  two  stations, 
the  transmitting  and  receiving.  At  the  former 
there  is  a  battery  of  12  volts,  giving  4  amperes  and 
50  watts ;  a  special  form  of  break  works  in  methyl- 
ated spirits,  and  is  driven  by  a  motor,  which  is 
supplied  with  current  by  a  special  local  battery  and 
a  primary  condenser.  The  current  is  next  led 
through  the  primary  by  an  inductor,  a  special  form 
of  induction  coil  having  a  large  core  and  a  very 
heavy  winding  on  the  secondary  circuit.  The  cur- 
rent now  passes  through  a  secondary  condenser  to 
adjustable  series  and  parallel  spark-gaps.  The  elec- 
tric waves  generated  by  this  arrangement  are  taken 
(293) 


294      prospector's  field-book  and  guide. 

to  earth  by  means  of  two  iron  spikes  driven  two  to 
three  inches  into  the  ground. 

The  receiving  set  comprises  two  similar  iron 
spikes,  driven  into  the  ground  to  a  depth  of  an  inch 
or  two,  and  connected  up  to  a  tripod  on  which  are 
placed  a  series  parallel  and  with  a  transformer  and 
two  delicate  receivers  or  resonators.  The  inter- 
rupter breaks  contact  700  times  a  minute. 

By  adjusting  his  earth  connections  the  operator 
can  focus  the  waves  on  any  field  that  he  may  wish 
to  explore ;  the  lines  of  force  travel  outward  and 
onward  until  they  reach  the  iron  spikes  in  the  re- 
ceiving set.  When  this  occurs,  the  observer  can  by 
means  of  the  resonators  detect  their  presence  by 
hearing  the  noise  of  the  break,  or  by  the  sparking 
across  the  gaps. 

Now,  in  a  normal  condition,  i.  e.,  if  the  ground 
be  of  a  homogeneous  character,  the  prospector 
should  hear  the  noises  loudest  when  exactly  oppo- 
site the  center  of  the  base  line  of  the  transmitting 
station. 

The  existence,  however,  of  a  vein  or  reef  contain- 
ing metal  has  the  tendency  of  throwing  the  waves 
out  of  normal  course,  by  reason  of  the  fact  that  it 
has  a  different  conductivity  from  the  material  by 
which  it  is  surrounded.  The  prospector  must  there- 
fore make  his  earth  connections  in  different  places, 
and  shift  his  position  until  he  can  detect  the  pres- 
ence of  the  waves.  When  directly  over  the  lode, 
the  noise  in  the  resonators  will  be  loudest. 

Condenser-discharges  from  lodes  manifest  them- 


APPENDIX.  295 

selves  as  overtones  in  the  receivers,  and  at  certain 
spots  or  nodal  points  the  noise  will  cease  altogether 
owing  to  the  influence  of  the  waves. 

The  condenser-discharges  can  be  heard  over  some 
lodes  when  the  distance  from  the  inductor  is  so  great 
that  the  noise  of  the  break  or  of  the  spark-gap  can- 
not be  heard  ;  thus  they  form  a  great  assistance  to 
prospecting,  helping  to  determine  not  only  the  posi- 
tion and  depth  of  a  mineral  deposit,  but  also,  to  a 
great  extent,  its  nature  and  characteristics. 

The  area  to  be  energized  by  the  electrical  waves 
may  be  as  small  as  300  square  feet  and  as  large  as 
30  square  miles,  and  the  terminals  may  be  placed 
hundreds  of  yards  apart. 

It  will,  of  course,  be  necessary  to  train  mining 
engineers  and  prospectors  in  the  use  of  the  instru- 
ments and  in  the  detection  of  the  presence  of  the 
waves.  The  whole  outfit  is,  however,  simple  and 
easy  to  work  with.  Its  development  during  the 
next  few  years  will  be  watched  with  interest  by  all 
interested  in  mining  operations. 

WEIGHTS  AND  MEASURES. 

British  weights  and  measures,  and  those  used  in 
our  country,  are  based  upon  the  weight  of  a  cubic 
inch  of  distilled  water  at  62°  Fall.,  and  30  inches 
height  of  the  barometer,  the  maximum  density. 
This  was  decided  by  Parliament,  in  the  reign  of 
George  IV.,  to  be  252.458  grains.  Recent  experi- 
ments, however,  show  that  a  cubic  inch  of  water  at 


the  temperature  of  maximum  density  is  252.286 
standard  grains.  On  this  account  scientists  are 
urging  the  readjustment  of  the  gallon,  bushel,  etc., 
but  at  present  the  tables  below  are  correct.  See  also 
No.  8. 

Weights  and  measures  of  various  nations  : — 

No.  1. — English  Length. 

3  barleycorns  =     1  inch. 

12  inches  =     1  foot. 

3  feet  =     1  yard. 

5£  yards  =     1  rod,  pole,  or  perch  (16J  feet). 

4« poles  or  100  links     =     1  chain  (22  yards  or  66  feet). 
10  chains  =     1  furlong  (220  yards  or  660  feet). 

8  furlongs  =     1  mile  (1760  yards  or  5280  feet). 

A  span  =  9  inches  ;  a  fathom  =  6  feet ;  a  league  =  3  miles  ;  a 
geographical  mile  =  6082.66  feet,  same  as  nautical  knot,  60  being  a 
degree,  i.  e.,  69.121  miles. 

Particular  Measures  of  Length. 

A  point,  7\  of  an  inch.  A  pace,  military,  2  feet,  6  inches. 

A  line,  j1^  of  an  inch.  A  pace,  geometrical,  5  feet. 

A  palm,  3  inches.  A  cable's  length,  120  fathoms. 

A  hand,  4  inches.  A  degree  (average),  69^  miles. 
A  link,  7.92  inches. 

No.  2. — Surface  Measure. 

144  square  inches  =  1  square  foot. 

9  square  feet  =b  1  square  yard. 

30^  square  yards  =  1  pole,  rod,  or  perch  (square). 

16  poles  (square)  =  1  chain  (sq.)  or  484  sq.  yds. 

40  poles  =  1  rood  (sq.)  or  1210  sq.  yds. 

10  chains  or  4  roods  =  1  acre  (4840  sq.  yds.). 

640  acres  =  1  sq.  mile. 


APPENDIX 

No.  3. — Surface 

Measure  in  Feet. 

9  square  feet 

= 

1  square  yard. 

272i     "       " 

= 

1  pole,  rod,  or  perch. 

4,356       "       " 

= 

1  square  chain. 

10,890       *t       i( 

— 

1  square  rood. 

43,560       "       " 

= 

1  acre. 

27,878,400       "       " 

= 

1  square  mile. 

297 


No.  4. — Solid  Measure. 

1728  cubic  inches    =     1  cubic  foot. 
27  cubic  feet         =     1  cubic  yard. 
16 j  feet  long,  1  foot  high,  and  H  feet  thick  —  1  perch  stone  = 
24f  cubic  feet. 

No.  5. — Troy  Weight. 
Platinum,  gold,  silver,  and  some  precious  stones 
are  weighed  by  Troy  weight,  diamonds  by  carats 
of  4  grains  each. 


24  grains 

20  pennyweights 

12  ounces 

No.  6.- 

16  drams 
16  ounces 
14  pounds 

2  stones 

4  quarters 
20  hundred-weight 


=     1  pennyweight. 

=     1  ounce  (480  grains). 

=     1  pound  (5760  grains). 

-Avoirdupois  Weight. 

=     1  ounce  (437-J  grains). 
=     1  pound  (7000  grains). 
=     1  stone. 
=     1  quarter. 

1  hundred-weight  (112  pounds). 

1  ton  (long  ton)  (2240  pounds). 


No.  7. — Weight  by  Specific  Gravity. 
Frequently    the    weight   of    masses    is   required 
where  it  is  very  inconvenient,  or,  perhaps,  impos- 
sible to  use  scales.     The  following  method  may  be 
sufficiently  accurate : — 


298      prospector's  field-book  and  guide. 

Find  the  average  specific  gravity  of  the  mass 
either  by  actual  weight  of  a  piece  or  by  the  follow- 
ing table.  Then  measure  the  cubic  contents  of  the 
mass  as  nearly  as  possible  and  multiply  by  the 
weight  of  a  cubic  foot.  Thus,  a  mass  of  limestone 
(say  good  marble)  measures  40  cubic  feet.  The 
specific  gravity  of  good  marble  is  2.6,  that  is,  it  is 
2.6  as  heavy  as  a  cubic  foot  of  water,  which  weighs 
62.5  pounds.     Therefore         62.5 

2.6 


3750 
1250 


162.50 
A  cubic  foot  of  good  marble  weighs  162.5  pounds, 
and  the  40  cubic  feet  will  weigh         162.5 

40 


6500.0 
or  about  3|  tons.  Of  course  all  rock  masses  have 
not  plane  sides,  and  the  irregularity  requires  some 
calculation  and  various  allowances  which  the  pros- 
pector must  make,  and  can  easily  do  with  a  little 
consideration. 

When  greater  accuracy  of  specific  gravity  and  of 
bulk  is  desired  for  small  masses,  and  no  scales  are 
at  hand,  the  following  plan  may  be  very  satisfac- 
torily adopted.  Fill  a  tub  or  hogshead  or  large  box 
with  rain  water,  after  having  inserted  a  tube  or 
piece  of  tin  pipe  into  the  upper  edge.  Pour  in  more 
water  until  it  will  hold  no  more  without  running 


APPENDIX.  299 

out  of  the  spout.  Introduce  the  mass  of  rock  and 
catch  all  the  water  which  runs  out  of  the  pipe. 
Now  measure  the  overflow ;  this  represents  the 
exact  cubic  measure  of  the  rock  introduced. 

1  gallon  contains 231  cubic  inches. 

1  quart         "        57.75  or  57f  cubic  inches. 

1  pint  "        28.87  or  28|     "  " 

1  gill  "        7.21  or    7|     " 

See  Appendix,  No.  8. 

Suppose  the  overflow  was  8  gallons,  1  quart,  4J 
gills,  and  that  the  specific  gravity  of  the  rock  or  ore 
was  6.5  by  the  table  below.  Then  the  mass  will 
cause  an  overflow  of  1936.99  cubic  inches,  and  this 
is  208.99  more  than  one  cubic  foot,  or  about  1.120 
of  a  cubic  foot  for  the  mass. 

Since  6.5  was  the  specific  gravity  of  the  ore, 
6.5x62.5  pounds  =  406.25,  which  would  be  the 
weight  of  a  cubic  foot  of  the  ore,  and  406.25  x  1.120 
=  455  pounds,  the  exact  weight  of  the  mass  you 
introduced  into  the  water. 

Specific  Gravity,  how  to  Find.  Where  the 
mass  is  of  very  nearly  the  same  density  in  all  parts, 
the  specific  gravity  may  be  taken  of  a  small  part  as 
follows : 

Suspend  the  scales  so  that  they  will  be  steady 
weigh  about  an  ounce  or  pound  of  the  ore  accu- 
rately, then  tie  the  ore  by  a  horse-hair  or  a  fine  silk 
thread  to  the  hook  that  holds  one  of  the  scales,  and 
let  it  (the  ore)  hang  below  the  scale  pan,  and  then 
weigh  the  ore  entirely  submerged  in  water.  The 
thread  or  hair  may  be  attached  to  the  centre  of  the 


300      prospector's  field-book  and  guide. 

scale  pan  and  weighed  in  that  way,  but  the  pan  in 
either  case  must  remain  on  the  scales  just  as  before. 
Then  the  weight  in  air  divided  by  the  weight  in  air 
minus  the  weight  in  water,  is  the  specific  gravity  ; 
e.  g.j  a  piece  of  ore  weighs  in  air  100  grains,  in 
water  80  grains,  then  100  divided  by  (100—80  = 
20)  =  5,  the  specific  gravity  of  that  piece  of  ore. 
You  may  now  proceed  as  in  the  case  of  the  marble 
block. 

No.  8. — Special  Weights,  etc. 

One  cubic  foot  of  water  is  equal  to  7.475  U.  S. 
gals,  of  231  cubic  inches  each,  or  7J  gallons  nearly  ; 
or  6.2321  Imperial  gals,  of  277^  cubic  inches  each. 
This,  with  what  follows,  is  important  in  the  con- 
struction of  tanks,  pools,  etc.,  where  contents, 
weight,  and  pressure  are  to  be  considered. 

It  should  be  remembered  that,  although  the  Eng- 
lish Imperial  gallon  is  277 J  cubic  inches  =  10  lbs. 
avoir,  of  distilled  water  at  62°  Fah.,  Bar.  30  inches, 
and  equal  to  277.274  cubic  inches,  the  United  States 
standard  gallon  is  231  inches,  or  58372.1754  grains, 
or  8.3389  lbs.  of  distilled  water  maximum  density. 
This  is  almost  exactly  =  to  a  cylinder  7  inches 
diameter,  6  inches  high.  The  beer  gallon  =  282 
inches. 

One  gallon  =  8.3389  lbs.;  one  quart  =  2.0847 
lbs.;  one  pint  =  1.0423  lbs.;  one  gill  =  0.2606  lb., 
U.  S.  standard  measure.  One  cubic  foot  of  water 
=  62.3210  lbs.,  British  weight;  recent  and  correct, 
62.278. 


APPENDIX. 


301 


No.  9. — French  Measures. — Length. 


Millimetre  ( j^^  of  a  metre) 
Centimetre  (rf0-       "       " 
Decimetre  (TXo  "       " 

Metre  (the  unit  of  length) 
Decametre  (10  metres) 
Hectometre  (100  metres) 
Kilometre  (1000  metres) 
Myriametre  (10,000  metres) 


.03937  inch. 
.3937      " 
3.937 
39.3708      "     or  3.2809  ft. 
32.809  ft.  or  10.9363  yds. 
109.3633  yards. 
1093.63  yds.  or  .62138  mile. 
6.2138  miles. 


Surface. 

Centiare  ( j^  of  an  are  or  sq.  metre 
Are  (unit  of  surface) 

Decare  (10  ares) 

Hectare  (100  ares) 


-  { 


1.1960  sq.  yds. 
119.6033  sq.  yards  or 

.0247  acre. 
1196.033  sq.  yards  or 

.2474  acre. 
11960.33  sq.  yards  or 

2.4736  acres. 


Solid  Measure. 


Decistere  (y1^  of  a  stere) 
Stere  (cubic  metre) 
Decastere  (10  steres) 


=        3.5317  cubic  feet. 
=      35.3166     "      " 
=    353.1658     "      " 

Weight. 


Milligramme  (ToXoo  °f  a  gramme)  =  .0154  grain. 


Centigramme  (T^ 
Decigramme  (y^ 
Gramme  (unit  of  weight) 
Decagramme  (10  grammes) 


)  —  .1544  grain. 
)  =  1.544  grains. 

==■  15.44  grains. 

==  154.4  grains. 


1,544  grains. 


Hectogramme  (100      "       ) 

Kilogramme  (1000      wt      ) 

Myriagramme  (10,000  grammes)    —  22.057  pounds. 


f  3.2167  ozs. 
j  Troy  or 
■  3.5291  ozs. 
L     Avoir. 


=  32£  ozs.  or  2.2057  pounds. 


302      prospector's  field-book  and  guide. 

No.  10. — Specific  Gravity  of  Metals, 
Ores,  Rocks,  etc. 

Platinum 16-21 

Gold 16-19.5 

Mercury 13.5 

Lead 11.35-11.5 

Silver 10.1-11.1 

Copper 8.5-8.9 

Iron  when  pure 7.78 

Iron,  cast,  average 6.7;  foundry  6.9  to  7 

Ores  :  associated  with  gold  and  silver. 

(Gold)  Iron  pyrites 4.8-5.2 

Copper  pyrites 4.0-4.3 

(Silver)  Galena 7.2-7.7 

Glance  (silver) 7.2-7.4 

Euby  silver  (dark) 5.7-5.9 

"      (light) 5.5-5.6 

Brittle  silver  (sulphide) 5.2-6.3 

Horn  silver 5.5-5.6 

Other  Ores. 

Zinc  blende 3.7-4.2 

Mercury  (Cinnabar) 8.8-9.9 

Tin — tinstone,  cassiterite 6.4-7.6 

Tin  pyrites 4.3-4.5 

Copper — Red  or  ruby  copper 5.7-6.15 

Gray.  . 5.5-5.8 

Black  oxide 5.2-6.3 

Pyrites 4.1-4.3 

Carbonate  (Malachite) 3.5-4.1 

Lead — sulphide  (Galena) 7.2-7.7 

Carbonate  (white  lead) 6.4-6.6 

Zinc— Blende 3.7-4.2 

Calamine 4.0-4.5 

Iron— Hematite  (red) •    •    •    .4.5-5.3 

Magnetic 4.9-5.9 

Brown  hematite 3.6-4.0 

Spathic  (carbonate) 3.7-3.9 

Pyrites  (mundic) 4.8-5.2 


APPENDIX.  303 

Antimony — gyray  sulphide 4.5-4.7 

Nickel — Kupfer  nickel 7.3-7.5 

Cobalt— Tin-white 6.5-7.2 

Glance 6.0 

Pyrites 4.8-5 

Bloom 2.91-2.95 

Earthy 3.15-3.29  . 

Manganese — Black  oxide 4.7-5.0 

Wad,  Bog  manganese       2.0-4.6 

Bismuth— Sulphide ,       6.4-6.6 

Oxide 4.3 

Minerals  of  Common  Occurrence. 

Quartz 2.5-2.8 

Fluorspar 3.0-3.3 

Calc  spar 2.5-2.8 

Barytes 4.3-4.8 

Granite  \  2  4_2  7 

Gneiss  / 

Mica  slate 2.6-2.9 

Syenite 2.7-3.0 

Greenstone  trap 2.7-3.0 

Basalt 2.6-3.1 

Porphyry 2.3-2.7 

Talcose  slate 2.6-2.8 

Clay  slate 2.5-2.8 

Chloritic  slate 2.7-2.8 

Serpentine 2.5-2.7 

Limestone  and  Dolomite 2.5-2.9 

Sandstones 1.9-2.7 

Shale 2.8 

Other  minerals  are  mentioned   in  the  text  with   their  specific 
gravities. 

No.  11. — A  Ton  Weight  of  the  Following  will 
Average  in  Cubic  Feet  : 

Earth  21  cubic  feet.  Pit  sand       22  cubic  feet. 

Clay  18       "      "  Biversandl9      "      " 

Chalk  14      "      "  Marl  18      "      " 

Coarse  gravel  19      "      "  Shingle        23      "       " 


304      prospector's  field-book  and  guide. 

Assay  -of  Gold  by  the  Touchstone.* 

This  is  a  rough  and  rapid  method  of  approxi- 
mately ascertaining  the  quality  of  a  gold  alloy 
without  injury  to  the  article,  as  is  the  case  in  dry 
and  wet  assaying. 

An  experienced  person  may  determine  the  correct 
standard  within  1  per  cent,  of  the  truth.  The  method 
is  based  on  the  fact  that  the  richer  an  alloy  is  in 
gold,  the  more  clearly  does  a  streak  drawn  with  it 
on  a  black  ground  exhibit  a  pure  golden  yellow 
color,  and  the  less  it  is  attacked  by  a  test  acid. 

The  touchstone  is  a  hard  siliceous  stone  of  a  black 
color,  its  surface  being  prepared  and  left  so  that  it 
will  just  abrade  the  metal  from  any  sharp  angle  of 
the  alloy  when  the  latter  is  drawn  over  the  stone. 

In  order  to  ascertain  the  quality  of  the  alloy,  its 
streak  is  compared  with  streaks  drawn  by  alloys  of 
known  fineness,  called  touch  'needles,  of  which  five 
series  are  required. 

1.  Red  series,  consisting  of  gold  and  copper,  the 
gold  increasing  by  half  carats  in  successive  needles. 

2.  White  series  contains  gold  and  silver. 

3.  Mixed  series,  in  which  the  quantities  of  silver 
and  copper  alloyed  with  the  gold  are  equal. 

4.  Unequal  mixed  series,  in  which  the  silver  is  to 
the  gold  as  2  :  1. 

5.  Series  in  which  the  silver  is  to  the  copper  as 
1:2. 

*From  Hiorns's  "Practical  Metallurgy  and  Assaying." 


APPENDIX.  305 

Besides  these,  special  needles  are  prepared  for  dif- 
ferent kinds  of  work. 

The  mark  left  on  the  stone  by  the  alloy  having 
been  matched  with  the  corresponding  mark  of  one 
of  the  touch  needles  it  is  assumed  to  have  the  same 
composition.  To  confirm  this  assumption,  a  drop 
of  acid  is  placed  on  each  streak,  allowed  to  work  for 
some  time,  and  its  effect  observed  in  each  case,  then 
wiped  off  to  see  if  the  mark  is  left  unchanged. 

The  test  acid  consists  of :  98  parts  pure  nitric  acid, 
2  parts  hydrochloric  acid,  25  parts  distilled  water. 

The  first  streak  made  by  a  body  is  discarded,  as 
in  the  case  of  colored  gold,  for  example,  the  surface 
having  a  different  composition  to  the  general  mass. 

The  above  test  mixture  has  no  effect  on  alloys  of 
18  carats  and  upwards,  so  that  streaks  made  by 
these  alloys  will  not  be  wiped  off  with  a  linen  rag 
after  treating  with  acid.  Pure  nitric  acid  has  no 
effect  on  alloys  of  15  carats  upwards. 

Estimation  of  Gold  in  Alloys  (Hiorns). 

In  places  where  a  large  number  of  assays  have  to 
be  conducted  a  special  set  of  weights  is  employed, 
as  with  silver,  the  unit  quantity  being  termed  the 
assay  pound,  which  is  subdivided  into  carats,  carat 
grains,  eights,  and  excess  grains.  The  amount 
taken  as  a  unit  may  be  10  grains  or  half  a  gramme 
=s  7.716  grains.  The  relation  of  the  parts  are 
well  shown  in  the  following  table  by  Prof.  Roberts- 
Austen  : 
20 


306      prospector's  field-book  and  guide. 


Excess 
Grains. 

Decimal 
Equiva- 
lent. 

Eights. 

1 

.1736 

Carat 
Grains. 

1 

7.5 

1.3021 

Carats. 

1 

8 

60 

10.416 

Assay 
Pound. 

1 

4 

32 

240 

41.6 

1 

24 

96 

768 

5760 

1000. 

The  excess  grains  in  one  assay  pound  are  the 
same  as  the  number  of  grains  in  the  troy  pounds. 

Gold  is  reported  to   the  trade  according  to  the 

above  table,  in  carats  or  the  decimal  equivalents. 

Thus  pure  gold  is  24  carats  or  1000  fine ;  standard 

22  x  1000 
gold,  22  carats  =    ^ =  916.66  fine. 

When  an  alloy  is  slightly  "  worse "  than  the 
standard,  it  is  said  to  be  "  worse  so  much."  When 
above  the  standard,  the  alloy  is  called  "  better  so 
much,"  the  difference  being  expressed  in  carat 
grains,  eights,  and  excess  grains,  or  in  its  decimal 


APPENDIX. 


307 


equivalent.     In  both  cases  the  excess  grains  repre- 
sent gold  present  in  excess  of  the  report. 

Standard  Values  of  Gold  in  Different 
Countries. 


Countries. 


England \ 

(one  troy  ounce)      / 

United  States  .  .  .  \ 
(one  troy  ounce)      J 

France  (Kilogramme), 

Germany  ' ' 


1,000 
(24  carats). 


£4  4  10 

$20.67 

Fr.  3,444.44 
Mk.  2,790 


916.66 
(22  carats). 


£3  17  10 

$18.95 

Fr.  3,157.40 
Mk.2,474.16 


900 
(21.6  carats). 


£3  16  6 

$18.6 

Fr.  3,100 
Mk.  2,511 


Power  for  Mills. 

As  the  Pelton  wheel  seems  to  find  the  most  fre- 
quent application  in  California,  it  may  be  conveni- 
ent to  have  the  following  rule,  applicable  to  this 
wheel : 

When  the  head  of  water  is  known  in  feet,  multi- 
ply it  by  0.0024147,  and  the  product  is  the  horse- 
power obtainable  from  one  miner's  inch  of  water. 

The  power  necessary  for  different  mill  parts  is  : 

For  each  850  lbs.  stamp,  dropping  6  inches  95  times  per 

minute 1.33  H.  P. 

For  each  750  lbs.  stamp,  dropping  C  inches  95  times  per 

minute 1.18       " 

For  each  650  lbs.  stamp,  dropping  6  inches  95  times  per 

minute .    .  1.00       " 

For  an  8-inch  by  10-inch  Blake  pattern  rock  breaker     .9.00      " 
For  a  Frne  or  Triumph  vanner  with  220  revolutions  per 

minute 0.50       " 


308      prospector's  field-book  and  guide. 

For  a  4-foot  clean-up   pan,  making  30  revolutions  per 

minute 1.50  H.  P. 

For  an  amalgamating  barrel,  making  30  revolutions  per 

minute 2.50       " 

For   a   mechanical    batea,    making   30   revolutions   per 

minute 1.00       " 

Boring. 
Rock  is  bored  with  jumpers  of  10  to  18  lbs.,  used 
alone  or  with  boring  bars  and  hammer.  The 
former  are  more  effective,  but  can  only  be  used 
perpendicularly,  or  nearly  so,  and  with  rock  of 
moderate  hardness  ;  they  require  more  skill. 

18  lb.  hammers  are  used  for  3  inch  boring  bars. 
16  lb.         "  "  "       2 j  inch  boring  bars. 

14  1b.         "  l<  k'       2  and  If  inch  boring  bars. 

5  to  7  lb.         "  "  "       1  inch  boring  bars. 

The  boring  bars  may  be  made  of  lj-inch  bar 
iron  of  various  lengths,  with  steel  bits  up  to  3 
inches.  A  bit  should  bore  from  18  to  24  feet  with 
each  steeling,  and  requires  to  be  sharpened  once  for 
every  foot  bored. 

Diamond  Drill. 

This  drill  is  applicable  to  sinking  a  bore-hole  for 
prospecting  for  minerals  or  water,  shafts,  etc.,  or 
blasting  under  water. 

It  consists  of  a  circular  row  of  "  carbonados,"  a 
species  of  diamond,  set  in  a  circular  steel  ring. 
This  is  attached  to  a  hollow  steel  tube,  which  is 
kept  rotating  at  about  250  revolutions  per  minute, 
pressed  forward  by  a  force  varying  from  400  to  800 
lbs.,  according  to  the  nature  of  the  rock.     Water  is 


APPENDIX. 


309 


supplied  through  the  tube,  which  washes  out  the 
debris  and  cools  the  diamonds. 

Granite  and  the  hardest  limestones  are  penetrated 
at  the  rate  of  2  or  3  inches  per  minute,  sandstones 
4  inches,  quartz  1  inch. 

The  diamond  drill  is  not  effective  in  soft  strata, 
such  as  clay,  sand  and  alluvial  deposits. 

The  Chemical  Elements,  their  Symbols,  Equiva- 
lents and  Specific  Gravities. 


Na 


Aluminium    . 
Antimony      .    . 
Arsenic  . 
Barium   .  .    .    - 
Bismuth     .    .    • 
Boron 
Bromine 

Cadmium      .    .     . 
Caesium .       ... 
Calcium  . 
Carbon    .      ... 
Cerium  .    .    . 

Chlorine  .  .  . 
Chromium  ... 
Cobalt  .... 
Columbium 

Copper 

Didymium    .    .    . 

Erbium 

Fluorine    .... 
Gallium  . 
Glucinum  . 
Gold  (Aurum)  .  . 
Hydrogen  .... 
Indium   .       ... 

Iodine    

Iridium  . 
Iron  (Ferrum)  . 
Lanthanum    . 
Lead  (Plumbum) 


Symbol. 

Atomic 
Weight. 

Specific 
Gravity. 

Al. 

27.5 

2.56 

Sb. 

122.0 

6.70 

As. 

75.0 

5.70 

Ba. 

137.0 

4.00 

Bi. 

210.0 

9.7 

B. 

11.0 

2.63 

Br. 

80.0 

5.54 

Cd. 

112.0 

8.60 

Cs. 

133.0 

1.88 

Ca. 

40.0 

1.58 

C. 

12  0 

3.50 

Ce. 

92.0 

6.68 

CI. 

35.5 

2.45 

Cr. 

52.5 

6.81 

Co. 

58.8 

7.7 

Cb. 

184.8 

6.00 

Cu. 

63.5 

8.96 

Di. 

96.0 

6.54 

E. 

112.6 

— 

F. 

19.0 

1.32 

Ga. 

69.9 

5.9 

Gl. 

9.5 

2.1 

An. 

196.7 

19.3 

H. 

1.0 

0.069 

In. 

113.4 

7.4 

I. 

!     127.0 

4.94 

Ir. 

;     198.0 

21.15 

Fe. 

!       56.0 

7.79 

La. 

90.2 

11  37 

Pb. 

!     207.0 

11.44 

310      prospector's  field-book  and  guide. 

The  Chemical  Elements,  their  Symbols,  Equiva- 
lents and  Specific  Gravities. 


Name. 


Lithium 

Magnesium 

Manganese 

Mercury  (Hydrargyrum) 

Molybdenum 

Nickel 

Niobium 

Nitrogen 

Osmium 

Oxygen  ....... 

Palladium 

Phosphorus 

Platinum    .  .... 

Potassium  (Kalium)  .    - 

Rhodium 

Rubidium 

Ruthenium 

Selenium 

Silicon 

Silver  (Argentum)   .  .    . 
Sodium  (Natrium)  .  .    . 

Strontium 

Sulphur 

Tantalium 

Tellurium 

Thallium 

Thorium 

Tin  (Stannum)     .... 

Titanium 

Tungsten  (Wolfram)  .    . 

Uranium 

Vanadium 

Yttrium 

Zinc  

Zirconium 


Symbol. 

Atomic 
Weight. 

Specific 
Gravity. 

Li. 

7.0 

0.59 

Mg. 

24.0 

1.75 

Mn. 

55.0 

8.01 

Hg. 

200.0 

13.59 

Mb. 

96.0 

8.60 

Ni. 

58.8 

8.60 

Nb. 

94.0 

6.27 

N. 

14.0 

0.972 

Os. 

199.0 

21.40 

0. 

16.0 

1.105 

Pd. 

106.5 

11.60 

P. 

31.0 

1.83 

Pt. 

197.4 

21.53 

K. 

39.0 

0.865 

Ro. 

104.3 

12.1 

Rb. 

85.4 

1.52 

Ru. 

104.4 

11.4 

Se. 

79.5 

4.78 

Si. 

28.0 

2.49 

Ag. 

108  0 

10.5 

Na. 

23  0 

0.972 

Sr. 

87.6 

2.54 

S. 

32.0 

2.05 

Ta. 

182.0 

10.78 

Te. 

129.0 

6.02 

Tl. 

204.0 

11.91 

Th. 

115.7 

7.8 

Sn. 

118.0 

7.28 

Ti. 

50.0 

4.3 

W. 

184.0 

17.6 

U. 

120.0 

18.4 

V. 

51.3 

5.50 

Y. 

61.7 

— 

Zn. 

65.0 

7.14 

Zr. 

89.5 

4.15 

The  figures  indicating  the  proportions  by  weight 
in  which  the  elements  unite  with  one  another  are 


APPENDIX.  311 

called  the  combining  or  atomic  weights,  because  they 
represent  the  relative  weights  of  the  atoms  of  the 
different  elements.  Since  hydrogen  is  the  lightest 
element,  it  is  taken  as  the  standard,  and  its  combin- 
ing or  atomic  weight  =  1. 

To  find  the  proportional  parts  by  weight  of  the  ele- 
ments of  any  substance  whose  chemical  formula  is 
known  : 

Rule. — Multiply  together  the  equivalent  and  the 
exponent  of  each  element  of  the  compound  ;  the 
product  will  be  the  proportion  by  weight  of  that 
element  in  the  substance. 

Example. — Find  the  proportionate  weights  of  the 
elements  of  alcohol,  C2H60  :    ' 

Carbon        Ca  =  equivalent  12  X  exponent  2  =  24 
Hydrogen  H6=         "  IX         "        6=    6 

Oxygen      O  =■■         "  16  X  "        1  —  16 

Of  every  46  lbs.  of  alcohol,  6  lbs.  will  be  H  ;  16  0  ; 
24  C. 

To  find  the  proportions  by  volume,  divide  by  the 
specific  gravity. 

Common  Names  of  Chemical  Substances. 
Common  Names.  Chemical  Names. 

Aqua  fortis.  Nitric  acid. 

Aqua  regia.  Nitro-hydrochloric  acid. 

Blue  vitriol.  Sulphate  of  copper. 

Cream  of  tartar.  Bitartrate  of  potassium. 

Calomel.  Chloride  of  mercury. 

Chalk.  Carbonate  of  calcium. 

Caustic  potash.  Hydrate  of  potassium. 

Chloroform.  Chloride  of  formyl. 


312 


PROSPECTOR  S    FIELD-BOOK    AND    GUIDE. 


Common  salt. 

Copperas  and  green  vitriol. 
Corrosive  sublimate. 
Dry  alum. 

Epsom  salts. 

Ethiops  mineral. 

Galena. 

Glauber1  s  salt. 

Glucose. 

Iron  pyrites. 

Jeweler's  putty. 

King's  yellow. 

Laughing  gas. 

Lime. 

Lunar  caustic. 

Mosaic  gold. 

Muriate  of  lime. 

Muriatic  acid. 

Nitre  or  saltpetre. 

Oil  of  vitriol. 

Potash. 

Realgar. 

Red  lead. 

Rust  of  iron. 

Sal  ammoniac. 

Salt  of  tartar. 

Slaked  lime. 

Soda. 

Spirits  of  hartshorn. 

Spirits  of  salt. 

Stucco  or  plaster  of  Paris. 

Sugar  of  lead. 

Verdigris. 

Vermilion. 

Vinegar. 

Volatile  alkali. 

Water. 

White  precipitate. 

White  vitriol. 


Chloride  of  sodium. 
Sulphate  of  iron. 
Bichloride  of  mercury. 
Sulphate  of  aluminium  and  potas- 
sium. 
Sulphate  of  magnesium. 
Black  sulphide  of  mercury. 
Sulphide  of  lead. 
Sulphate  of  sodium. 
Grape  sugar. 
Bisulphide  of  iron. 
Oxide  of  tin. 
Sulphide  of  arsenic. 
Protoxide  of  nitrogen. 
Oxide  of  calcium. 
Nitrate  of  silver. 
Bisulphide  of  tin. 
Chloride  of  calcium. 
Hydrochloric  acid. 
Nitrate  of  potash. 
Sulphuric  acid. 
Oxide  of  potassium. 
Sulphide  of  arsenic. 
Oxide  of  lead. 
Oxide  of  iron. 
Chloride  of  ammonia. 
Carbonate  of  potassium. 
Hydrate  of  calcium. 
Oxide  of  sodium. 
Ammonia. 
Hydrochloric  acid. 
Sulphate  of  lime. 
Acetate  of  lead. 
Basic  acetate  of  copper. 
Sulphide  of  mercury. 
Acetic  acid  (diluted). 
Ammonia. 
Oxide  of  hydrogen. 
Ammoniated  mercury. 
Sulphate  of  zinc. 


APPENDIX.  313 


PROSPECTORS'  POINTERS. 

OLD-TIMER   INSTRUCTS  THE   TENDERFOOT    PROSPECTOR 
ON    LOCATING. 

Take  a  soft  pine  board,  and  a  hard  lead  pencil, 
and  the  writing  will  sometimes  outlast  your  claim. 
I  have  seen  such  notices  that  have  withstood  the 
storms  of  seven  or  eight  years  and  still  remain 
legible.  There  is  a  great  variety  of  ways  to  write 
a  notice ;  and  nearly  every  prospector  has  his  own 
way.  But  the  briefest  and  most  concise  way  is  as 
good  as  any,  and  the  easiest.  Now,  I'll  write  you 
one  for  the  Catharine  this  way  : 

Catharine  Lode. 

Notice  is  hereby  given  that  I,  the  undersigned 
citizen  of  the  United  States,  having  complied  with 
Chapter  36,  Title  32,  Revised  Statutes  of  the  United 
States,  and  the  local  regulations  of  Barker  district, 
claim  by  right  of  discovery,  1500  feet  in  length,  and 
600  feet  in  width,  along  the  mineral-bearing  vein, 
to  be  known  as  the  Catharine  (or  any  other  name). 

Beginning  at  centre  of  discovery  shaft  and  run- 
ning :  "  How  far  do  you  run  northerly  ?  " 

"  Seven  hundred  feet  northeast." 

"  Seven  hundred  feet  in  a  northerly  direction  and 
800  feet  in  a  southerly  direction. 

"  Always  say  northerly,  southerly,  easterly,  and 
westerly  in  writing  notices.  Don't  give  it  any  spe- 
cific direction.     When  you  say  '  northerly,'  it  gives 


314 

you  a  chance  to  swing  your  stakes  all  round  the 
North  Pole,  if  necessary.  You  can  swing  your 
stakes  after  your  location  is  made  any  way  you 
want  to,  provided  there  are  no  conflicting  claims, 
unless  you  change  from  northerly  and  southerly  to 
easterly  and  westerly,  or  vice  versa.  In  that  case, 
you  have  to  make  an  amended  location  and  record 
it.  Let's  see.  Where  were  we  ?  Oh,  yes  ;  together 
with  300  feet  on  either  side  of  the  vein. 
"Located  this  18th  day  of  June,  1891." 
"  Locator — Tenderfoot,  Prospector." 
Now  that  is  all  that  is  necessary  to  hold  any 
claim,  as  far  as  the  notice  goes.  Some  prospectors 
put  in  a  claim  for  all  dips,  spurs,  angles,  and  varia- 
tions throughout  the  width,  breadth  and  depth  of 
the  claim ;  but  that's  all  foolishness.  The  law 
grants  you  all  the  spurs  and  angles  and  dips  you 
want.  You  just  go  ahead  and  do  as  the  law  re- 
quires you  to  do,  to  hold  any  mining  claim." — 
Butte  Bystander. 


GLOSSARY  OF  TERMS 


USED    [N    CONNECTION    WITH 

PROSPECTING,  MINING,  MINERALOGY,  GEOLOGY,  ETC. 


Abraded.     Reduced  to  powder. 

Acicular.     Needle-shaped. 

Adamantine.     Of  diamond  lustre. 

Adit.  A  nearly  horizontal  passage  from  the  surface  by  which  a 
mine  is  entered.  In  the  United  States  an  adit  is  usually  called  a 
tunnel. 

Aerolite.  A  stone  or  other  body  which  has  come  to  the  earth  from 
distant  space. 

Agate.     Name  given  to  certain  siliceous  minerals. 

Aggregation.     A  coherent  group. 

Alligator.     A  rock-breaker  operating  by  jaws. 

Alloy.     A  compound  of  two  or  more  metals  fused  together. 

Alluvium.  The  earthy  deposit  made  by  running  streams,  especi- 
ally in  times  of  Hood. 

Amalgamation.  The  production  of  an  amalgam  or  alloy  of  mer- 
cury; also  the  process  in  which  gold  and  silver  are  extracted  from 
pulverized  ores  by  producing  an  amalgam  from  which  the  mercury 
is  afterwards  expelled. 

Amorphous.      Without  any  crystallization  or  definite  form. 

Amygdaloid*.  Small  almond-shaped  vesicular  cavities  in  certain 
igneous  rocks,  partly  or  entirely  filled  with  other  minerals. 

Analysis  (in  Chemistry).  An  examination  of  the  substance  to  find 
out  the  nature  of  tiie  component  parts  and  their  quantities.  The 
former  is  called  qualitative  and  the  latter  quantitative  analysis. 

(315) 


316       prospector's  field-book  and  guide. 

Anemometer.  An  instrument  for  measuring  the  rapidity  of  an  air- 
current. 

Anticlinal.  The  line  of  a  crest,  above  or  under  ground,  on  the 
two  sides  of  which  the  strata  dip  in  opposite  directions.  The  con- 
verse of  synclinal. 

Apex.  In  the  U.  S.  Revised  Statutes,  the  end  or  edge  of  a  vein 
nearest  the  surface. 

Aqua  for 'tis.     Name  formerly  applied  to  nitric  acid. 

Aqua  regia.  A  mixture  of  nitric  and  hydrochloric  acids.  One 
volume  of  strong  nitric  to  three  or  four  of  hydrochloric  acid  is  a 
good  mixture. 

Arborescent.     Of  a  tree-like  form. 

Arenaceous.     Siliceous  or  sandy  (of  rocks). 

Argentiferous.     Containing  silver. 

Argillaceous.     Containing  clay. 

Arrastre.  Apparatus  for  grinding  and  mixing  ores  by  means  of  a 
heavy  stone  dragged  around  upon  a  circular  bed.  Chiefly  used  for 
ores  containing  free  gold. 

A  rsenite.     Compound  of  a  metal  with  arsenic. 

Assay.  To  test  ores  and  minerals  by  chemical  or  blow-pipe  ex- 
amination. 

Assay-ton.     A  weight  of  29.166f  grammes. 

Assessment-work.  The  work  done  annually  on  a  mining  claim  to 
maintain  possessory  title. 

Auriferous.     Containing  gold 

Axe  Stone.  A  species  of  jade.  It  is  a  silicate  of  magnesia  and 
alumina. 

Back  of  a  lode.     The  part  between  the  roof  and  the  surface. 

Back-shift.  The  second  set  of  miners  working  in  any  spot  each 
day. 

Bank  claim.     A  mining  claim  on  the  bank  of  a  stream. 

Banket.    Auriferous  conglomerates  cemented  together  with  quartz. 

Bar.  A  vein  or  dike  crossing  a  lode ;  also  a  sand  or  rock  ridge 
crossing  the  bed  of  a  stream. 

Bar-diggings.    Gold-washing  claims  located  on  ihe  bars  (shallows) 


GLOSSARY    OF    TERMS.  317 

of  a  stream,  and  worked  when  the  water  is  low,  or  otherwise  with 
the  aid  of  coffer-dams. 

Barilla.     Native  copper  disseminated  in  grains  in  copper  ores. 

Barrel-amalgamation.  The  amalgamation  of  silver  ores  in  wooden 
barrels  with  quicksilver,  metallic  iron,  and  water. 

Base  metals.  The  metals  not  classed  as  noble  or  precious.  See 
Noble  metals. 

Bases.  Compounds  which  are  converted  into  salts  by  the  action 
of  acids. 

Basin.  A  natural  depression  of  strata  containing  a  coal  bed  or 
other  stratified  deposit;  also  the  deposit  itself. 

Battery.  A  set  of  stamps  in  a  stamp  mill  comprising  the  number 
which  fall  in  one  mortar,  usually  five;  also  a  bulkhead  of  timber. 

Battery-amalgamation.  Amalgamation  by  means  of  mercury  placed 
in  the  mortar. 

Bed.  A  seam  or  deposit  of  mineral,  later  in  origin  than  the  rock 
below,  and  older  than  the  rock  above;  that  is  to  say,  a  regular  mem- 
ber of  the  series  of  formation,  and  not  an  intrusion. 

Bedded-vein.  A  lode  occupying  the  position  of  a  bed,  that  is, 
parallel  with  the  stratification  of  the  inclosing  rocks. 

Bed-rock.  The  solid  rock  underlying  alluvial  and  other  surface 
formations. 

Bed-way.  An  appearance  of  stratification,  or  parallel  marking,  in 
granite. 

Belly.     A  swelling  mass  of  ore  in  a  lode. 

Black  band.     A  variety  of  carbonate  of  iron. 

Black  flux.     A  mixture  of  charcoal  and  potassium  carbonate 

Blackjack.     Zinc-blende. 

Black  tin.     Tin  ore  ready  dressed  for  smelting. 

Blanch.     Lead  ore  mixed  with  other  minerals. 

Blanched  copper.     An  alloy  of  copper  and  arsenic. 

Blende.     Sulphide  of  zinc. 

Blind  level.     A  level  not  yet  connected  with  other  \rorkings. 

Blind  lode,     One  that  does  not  show  surface  croppings. 

Blossom.  The  oxidized  or  decomposed  outcrop  of  a  vein  or  coal 
bed.      Also  called  smut  and  (ailing. 


318      prospector's  field-book  and  guide. 

Blow-out.  1.  A  large  outcrop  beneath  which  the  vein  is  smaller. 
2.  A  shot  or  blast  is  said  to  blow  out  when  it  goes  off  like  a  gun,  and 
does  not  shatter  the  rock.  • 

Blue-john.     Fluorspar. 

Blue  lead.  The  bluish  auriferous  gravel  and  cement  deposit  found 
in  the  ancient  river-channels  of  California. 

Bluff.     A  high  bank  or  hill  with  a  precipitous  front. 

Bonanza.     A  body  of  rich  ore. 

Booming.  The  accumulation  and  sudden  discharge  of  a  quantity 
of  water  (in  placer-mining,  where  water  is  scarce).    See  also  Hushing. 

Bort.     Opaque  black  diamond. 

Botryoidal.     Like  a  bunch  of  grapes. 

Boulder.  A  fragment  of  rock  brought  by  natural  means  from  a 
distance,  and  usually  large  and  rounded  in  shape. 

Brasque.  A  lining  for  crucibles;  generally  a  compound  of  clay, 
etc.,  with  charcoal  dust. 

Breast.     The  face  of  a  working. 

Breccia.     A  conglomerate  in  which  the  fragments  are  angular. 

Buddie.  An  inclined  vat,  or  stationary  or  revolving  platform 
upon  which  ore  is  concentrated  by  means  of  running  water. 

Bullion.  Uncoined  gold  and  silver.  Base  bullion  is  pig  lead  con- 
taining silver  and  some  gold,  which  are  separated  by  refining. 

Buried  rivers.  .River  beds  which  have  been  buried  below  streams 
of  basalt  or  alluvial  drifts. 

Burr.     Solid  rock. 

Button.  The  globule  of  metal  remaining  in  a  crucible  at  the  end 
of  fusion. 

Cage.  A  frame  with  one  or  more  platforms  used  in  hoisting  in  a 
vertical  shaft. 

Cairngorm.  A  variety  of  quartz,  frequently  transparent;  used  as 
an  ornament. 

Calcareous.     Containing  carbonate  of  lime. 

Calcination.     Roasting  at  a  gentle  heat. 

Calcine.     To  expose  to  heat  with  or  without  oxidation. 

Calcite.     Carbonate  of  lime. 


GLOSSARY    OF    TERMS.  319 

Canon.     A  valley,  usually  precipitous;  a  gorge. 

Cap  or  cap-rock.  Barren  vein  matter,  or  a  pinch  in  a  vein,  sup- 
posed to  overlie  ore. 

Carat.  Weight,  nearly  equal  to  four  grains,  used  for  diamonds 
and  precious  stones.  With  goldsmiths  and  assayers  the  term  carat 
is  applied  to  the  proportions  of  gold  in  an  alloy;  24  carats  represents 
fine  gold.  Thus  18  carat  gold  signifies  that  18  out  of  24  parts  are 
pure  gold,  the  rest  some  other  metal. 

Carbonaceous.     Containing  carbon  not  oxidized. 

Carbonates.  The  common  term  in  the  West  for  ores  containing  a 
considerable  proportion  of  carbonate  of  lead. 

Carbonization.     Conversion  to  carbon. 

Case.     A  small  fissure  admitting  water  into  the  workings. 

Casing.     Clayey  material  found  between  a  vein  and  its  wall. 

Cawk.     Sulphate  of  baryta  (heavy  spar). 

Cement.  Gravel  firmly  held  in  a  siliceous  matrix,  or  the  matrix 
itself. 

Champion  lode.     The  main  vein  as  distinguished  from  branches. 

Chasing.     Following  a  vein  by  its  range  or  direction. 

Chert.     Hornstone;  a  siliceous  stone  often  found  in  limestone. 

Choke  damp.     Carbonic  acid  gas. 

Chlorides.     A  common  term  for  ores  containing  chloride  of  silver. 

Chloridize.  To  convert  into  chloride.  Applied  to  the  roasting  of 
silver  ores  with  salt,  preparatory  to  amalgamation. 

Chute.  A  channel  or  shaft  underground,  or  an  inclined  trough 
above  ground,  through  which  ore  falls  or  is  "  shot"  by  gravity  from 
:a  lower  to  a  higher  level. 

Claim.  The  portion  of  mining  ground  held  under  the  Federal 
;and  local  laws  by  one  claimant  or  association,  by  virtue  of  one  loca- 
tion and  record. 

Clay  slate.     A  slate  formed  by  the  induration  of  clay. 

Cleavage.  The  property  of  a  mineral  of  splitting  more  easily  in 
some  directions  than  in  others'. 

Cleavage  planes.     The  planes  along  which  cleavage  takes  place. 

Clinometer.  An  apparatus  for  measuring  vertical  angles,  particu- 
larly dips. 


320      prospector's  field-book  and  guide. 

Cobre  ores.     Copper  ores  from  Cuba. 

Oolor.     A  particle  of  gold  found  in  the  prospector's  pan. 

Concentration.  The  removal  by  mechanical  means  of  the  lighter 
and  less  valuable  portions  of  ore. 

Conchoidal.  Name  given  to  a  certain  kirid  of  fracture  resembling 
a  bivalve  shell. 

Concretion.  A  nodule  formed  by  the  aggregation  of  mineral  mat- 
ter from  without  round  some  centre. 

Conglomerate.  A  rock  consisting  of  fragments  of  other  rocks  (usu- 
ally rounded)  cemented  together. 

Consume.  The  chemical  and  mechanical  loss  of  mercury  in  amal- 
gamation. 

Contact.  The  plane  between  two  adjacent  bodies  of  dissimilar 
rock.  A  contact-vein  is  a.  vein,  and  a  contact-bed  is  a  bed,  lying,  the 
former  more  or  less  closely,  the  latter  absolutely,  along  a  contact. 

Contortion.     Crumpling  and  twisting. 

Coprolites.     Phosphate  of  lime;  petrified  excrements  of  animals. 

Counter.     A  cross  vein.     . 

Country,  or  Country  rock.  The  rock  traversed  by  or  adjacent  to 
an  ore  deposit. 

Course  of  a  lode.     Its  direction. 

Cradle.     See  Rocker. 

Cranch.     Part  of  a  vein  left  by  old  workers. 

Urate  dam.     A  dam  built  of  crates  filled  with  stone. 

Crater.     The  cup-like  cavity  at  the  summit  of  a  volcano. 

Cretaceous.     Chalky. 

Crevet.     A  crucible. 

Crevice.  A  shallow  fissure  in  the  bed-rock  under  a  gold  placer, 
in  which  small  but  highly  concentrated  deposits  of  gold  are  found; 
also  the  fissure  containing  a  vein. 

Cribbing.     Close  timbering,  as  the  lining  of  a  shaft. 

Cribble.     A  sieve. 

Cropping-out.     The  rising  of  layers  of  rock  to  the  surface. 

Cross-course.     An  intersecting  (usually),  a  barren  vein. 
-cut.     A  level  driven  across  the  course  of  a  vein. 


GLOSSARY    OF    TERMS.  321 

Cross-vein.     An  intersecting  vein. 
Cupriferous.     Containing  copper. 

Cyanidation.  Conversion  of  gold  into  a  double  cyanide  of  potas- 
sium and  gold  by  the  action  of  cyanide  of  potassium. 

Dead-roosting.  Roasting  carried  to  the  farthest  practicable  degree 
in  the  expulsion  of  sulphur. 

Bead-work.  Work  that  is  not  directly  productive,  though  it  may 
be  necessary  for  exploration  and  future  production. 

Debris.  The  fragments  resulting  from  shattering  and  disintegra- 
tion. 

Decrepitate.     To  crackle  and  fly  to  pieces  when  heated. 

Deep  Leads.  Alluvial  deposits  of  gold  or  tinstone  buried  below  a 
considerable  thickness  of  soil  or  rock. 

Delta.  The  alluvial  land  at  the  mouth  of  a  river;  usually  bounded 
by  two  branches  of  the  river,  so  as  to  be  of  a  more  or  less  triangular 
form. 

Dendritic.     Like  branches  of  trees. 

Denudation.     Rock  laid  bare  by  water  or  other  agency. 

Deoxidation.     The  removal  of  oxygen. 

Desilverization.     The  process  of  separating  silver  from  its  alloys. 

Desvlphurization.     The  removal  of  sulphur  from  sulphuret  ores. 

Detritus.  Accumulations  from  the  disintegration  of  exposed  rock 
surfaces. 

Development.     Work  done  in  opening  of  a  mine. 

Dialling.     Surveying  a  mine  by  means  of  a  dial. 

Diggings.  Applicable  to  all  mineral  deposits  and  mining  camps^ 
but  in  usage  in  the  United  States  applied  to  placer-mining  only. 

Dike.     A  vein  of  igneous  rock. 

Diluvium.     Sand,  gravel,  clay,  etc.,  in  superficial  deposits. 

Dip.     The  inclination  of  a  vein  or  stratum  below  the  horizontal. 

Disintegration.  The  breaking  asunder  of  solid  matter  due  to 
chemical  or  physical  forces. 

Dislocation.     The  displacement  of  rocks  on  either  side  of  a  crack. 

Divining  rod.     A  rod,  most  frequently  of  witch-hazel,  and  forked 

21 


322      prospector's  field-book  and  guide. 

in  shape,  used  according  to  an  old  but  still  extant  superstition  for 
discovering  mineral  veins  and  springs  of  water,  and  even  for  locating 
oil  wells. 

Discovery.  The  first  finding  of  the  mineral  deposit  in  place  upon 
a  mining  claim.  A  discovery  is  necessary  before  the  location  can  be 
held  by  a  valid  title.  The  opening  in  which  it  is  made  is  called 
discovery -shaft,  discovery-tunnel,  etc. 

Ditch.  An  artificial  water-course,  flume  or  canal  to  convey  water 
for  mining. 

Dolly.  An  apparatus  used  in  washing  gold-bearing  rocks  (Aus- 
tralia). 

Domes.     Strata  which  are  dipping  away  in  every  direction. 

Drift.  A  horizontal  passage  underground  ;  also  unstratified  dilu- 
vium. 

Druse.     A  crystallized  crust  lining  the  sides  of  a  cavity. 

Dry  ores.     Silver  ores  which  do  not  contain  lead. 

Dyke.     See  Dike. 

Efflorescence.  An  incrustation  of  powder  or  threads,  due  to  the 
loss  of  the  water  of  crystallization. 

Elements.     Substances  which  have  never  been  decomposed. 

Elutriation.  Purification  by  washing  and  pouring  off  the  lighter 
matter  suspended  in  water,  leaving  the  heavier  portions  behind. 

Entry.     An  adit. 

Erosion.     The  act  or  operation  of  wearing  away. 

Excrescence.     Grown  out  from  something  else. 

Exfoliate.     To  peel  off  in  leaves  from  the  outside. 

Exploitation.  The  productive  working  of  a  mine  as  distinguished 
from  exploration. 

Face.  In  any  adit,  tunnel,  or  slope,  the  end  at  which  work  is 
progressing  or  was  last  done. 

False  Bottom.  In  alluvial  mining  a  stratum  on  which  auriferous 
beds  lie,  but  which  has  other  bottoms  below  it. 

Fathom.     6  feet. 

Fault.     A  dislocation  of  the  strata  or  vein. 


GLOSSARY    OF    TERMS.  323 

Feather  Ore.     A  sulphide  of  lead  and  antimony. 

Feeder.     A  small  vein  adjoining  a  larger  vein. 

Feldspathie.     Containing  feldspar  as  the  principal  ingredient. 

Ferruginous.     Containing  iron. 

Fire-damp.     Light  carburetted  hydrogen  gas. 

Fissure-vein.     A  fissure  in  the  earth's  crust  filled  with  mineral. 

Flexible.     Capable  of  being  bent  without  elasticity. 

Flint.     A  massive  impure  variety  of  silica. 

Float-copper.  Fine  scales  of  metallic  copper  which  do  not  readily 
settle  in  water. 

Float-gold.  Fine  particles  of  gold  which  do  not  readily  settle 
in  water,  and  hence  are  liable  to  be  lost  in  the  ordinary  stamp-mill 
process. 

Float-ore.  Water- worn  particles  of  ore;  particles  of  vein -material 
found  on  the  surface,  away  from  the  vein  outcrop. 

Flocculent.     Cloudy,  resembling  lumps  of  wool. 

Floor.  The  rock  underlying  a  stratified  or  nearly  horizontal  de- 
posit, also  a  horizontal  flat  ore  body. 

Flume.     A  wooden  conduit  bringing  water  to  a  mine  or  mill. 

Flux.  A  salt  or  other  mineral  added  in  smelting  to  assist  fusion 
by  forming  more  fusible  compounds. 

Foliated.     Arranged  in  leaf-like  lamina  (such  as  mica  schist). 

Foot-wall.     The  wall  under  the  vein. 

Forfeiture.  The  loss  of  possessory  title  to  a  mine  by  failure  to 
comply  with  the  laws  prescribing  the  quantity  of  assessment  work,  or 
by  actual  abandonment. 

Formation.  The  series  of  rocks  belonging  to  an  age,  period  or 
epoch,  as  the  Silurian  formation. 

Fossil.  Term  applied  to  express  the  animal  or  vegetable  remains 
found  in  rocks. 

Founder  shaft.     The  first  shaft  sunk. 

Free.  Native,  uncombined  with  other  substances,  as  free  gold  or 
silver. 

Free-milling.  Applied  to  ores  which  contain  free  gold  or  silver, 
and  can  be  reduced  by  crushing  and  amalgamation,  without  roasting 
or  other  chemical  treatment. 


324      prospector's  field-book  and  guide. 

Fritting.  The  formation  of  a  slag  by  heat  with  but  incipient 
fusion. 

Fuller's  earth.  An  unctuous  clay,  usually  of  a  greenish-gray  tint, 
compact  yet  friable.     Used  by  fullers  to  absorb  moisture. 

Fuse.  In  blasting  the  fire  is  conveyed  to  the  blasting  agent  by 
means  of  a  prepared  tape  or  cord  called  the  fuse. 

Gad.     A  steel  wedge. 

Galiage.     Eoyalty. 

Gallery.     A  level  or  drift. 

Gangue.     The  mineral  associated  with  the  ore  in  a  vein. 

Gash.  Applied  to  a  vein  wide  above,  narrow  beljw,  and  termin- 
ating in  depth  within  the  formation  it  traverses. 

Geode.  A  cavity,  studded  around  with  crystals  or  mineral  matter, 
or  a  rounded  stone  containing  such  cavity. 

Geysers.     Intermittent  boiling  springs. 

Glacier.  A  body  of  ice  which  descends  from  the  high  to  the  low 
ground. 

Glance.     Literally,  shining.     Name  applied  to  certain  sulphides. 

Globule.     A  small  substance  of  a  spherical  shape. 

Goaves.     Old  workings. 

Gopher  or  Gopher-drift.  An  irregular  prospecting  drift,  following 
or  seeking  the  ore  without  regard  to  maintenance  of  a  regular  grade 
or  section. 

Gossan  or  Gozzan.  Hydrated  oxide  of  iron,  usually  found  at  the 
decomposed  outcrop  of  a  mineral  vein. 

Gravel  mine.  In  the  United  States,  an  accumulation  of  auriferous 
gravel. 

Grip.     A  small  narrow  cavity. 

Gh'it.     A  variety  of  sandstone  of  coarse  texture. 

Gubbin.     A  kind  of  iron  stone. 

Gulch.     A  ravine. 

Gullet.     An  opening  in  the  strata. 

Hade.     See  Underlay. 

Hanging-side  or  Hanging-wall,  or  Hanger.  The  wall  or  side  over 
the  vein. 


GLOSSARY    OP    TERMS.  325 

Hard  Head.  A  residual  alloy  containing  much  iron  and  arsenic, 
produced  in  the  refining  of  tin. 

Heading.  The  vein  above  a  drift;  also  an  interior  level  or  air- way- 
driven  in  the  mine. 

Heading  side.     The  under  side  of  a  lode. 

Heave.  An  apparent  lateral  displacement  of  a  lode  produced  by 
a  fault. 

Hog  back.  A  sharp  anticlinal,  decreasing  in  height  at  both  ends 
until  it  runs  out;  also  a  ridge  produced  by  highly  tilted  strata. 

Homogeneous.     Of  the  same  structure  throughout. 

Horse.     A  mass  of  country  rock  enclosed  in  an  ore  deposit. 

Hungry.  A  term  applied  to  hard  barren  vein  matter,  such  as 
white  quartz. 

Hushing.  The  discovery  of  veins  by  the  accumulation  and  sudden 
discharge  of  water,  which  washes  away  the  surface  soil  and  lays  bare 
the  rock.     See  Booming. 

Hydraulicking .  Washing  down  a  bank  of  earth  or  gravel  by  the 
use  of  pipes,  conveying  water  under  high  pressure. 

Hydrous.     Containing  water  in  its  composition. 

Igneous.  Resulting  from  the  action  of  fire,  as,  lavas  and  basalt 
are  igneous  rocks. 

Impregnation.  An  ore-deposit  consisting  of  the  country-rock  im- 
pregnated with  ore. 

Incline.  A  shaft  not  vertical;  also  &  plane,  not  necessarily  under 
ground. 

Incrustation.     A  coating  of  matter. 

Indicator  Vein.  A  vein  which  is  not  metalliferous  itself,  but,  if 
followed,  leads  to  ore  deposits. 

In  place.  Of  rock,  occupying,  relative  to  surrounding  masses,  the 
position  that  it  had  when  formed. 

In  situ.     In  place  where  formed. 

Intrusion.     Forcing  through. 

Irestone.     Hard  clay  slate:  hornstone;  horn-blende. 

Iridescent.     Showing  rainbow  colors. 


326         PROSPECTOR^    FIELD-BOOK    AND    GUIDE. 

Jigging.  Separating  ores  according  to  specific  gravity  with  a  sieve 
agitated  up  and  down  in  water.  The  apparatus  is  called  a  jig  or 
jigger. 

Jinny-road.     A  gravity  plane  underground. 

Jump.  To  take  possession  of  a  mining  claim  alleged  to  have  been 
forfeited  or  abandoned;  also,  a  dislocation  of  a  vein. 

Keckle-meckle.     The  poorest  kind  of  lead  ore. 
Kibbal  or  kibble.     An  iron  bucket  for  raising  ore. 
Kicker.     Ground  left  in  first  cutting   a  vein,  for  support  of  its 
sides. 

King's  yellow.     Sulphide  of  arsenic. 
Knits  or  knots.     Small  particles  of  ore. 

Lagoon.     A  marsh,  shallow  pond  or  lake. 
Lamellar.     In  thin  sheets. 
Lamina.     A  thin  plate  or  scale. 

Lava.     Eock  formed  by  the  consolidation  of  liquid  matter  which 
has  flowed  from  a  volcano. 
Leaching.     See  Lixiviation. 

Leads.  The  auriferous  portions  of  alluvial  deposits  marking  the 
former  courses  of  streams. 

Leath.     Applied  to  the  soft  part  of  a  vein. 

Lenticular.     Lens-like. 

Level.     A  horizontal  passage  or  drift  into  or  in  a  mine. 

Limp.     An  instrument  for  striking  the  refuse  from  the  sieve 
washing  ores. 

Litharge.     Protoxide  of  lead. 

Lixiviation.  The  separation  of  a  soluble  from  an  insoluble 
material  by  means  of  washing  with  a  solvent. 

Loadstone.  An  iron  ore  consisting  of  protoxide  and  peroxide  1 
iron;  Magnetite. 

Locate.     To  establish  a  right  to  a  mining  claim. 

Lode.     A  regular  vein  carrying  metal. 

Long  Tom.     A  kind  of  gold-washing  cradle. 


GLOSSARY    OF    TERMS.  327 

Magma.     Paste  or  groundwork  of  igneous  rocks. 
Mainway.     A  gangway  or  principal  passage. 
Marl.     Clay  containing  carbonate  of  lime. 
Mass-copper.     Native  copper  occurring  in  large  masses. 
Massicot.     See  Litharge. 

Matrix.  The  rock  or  earthy  material  containing  a  mineral  or 
metallic  ore;  the  gangue. 

Matt  or  Matte.  A  mass  consisting  chiefly  of  metallic  sulphides 
got  in  the  fusion  of  ores. 

Measures.     Strata  of  coal,  or  the  formation  containing  coal  beds. 

Meat-earth.     The  vegetable  mould. 

Metalliferous.     Metal-bearing. 

Metamorphic.     Changed  in  form  and  structure. 

Mine.  In  general,  any  excavation  for  minerals.  More  strictly, 
subterranean  workings,  as  distinguished  from  quarries,  placer  and 
hydraulic  mines,  and  surface  or  open  works. 

Mineral.     In  miners'  parlance,  ore. 

Mineralized.     Charged  or  impregnated  with  metalliferous  mineral. 

Mineral-right.  The  ownership  of  the  minerals  under  a  given  sur- 
face, with  the  right  to  enter  thereon,  mine  and  remove  them.  It 
may  be  separated  from  the  surface  ownership,  but,  if  not  so  separated 
by  distinct  conveyance,  the  latter  includes  it. 

Mine-rent.  The  rent  or  royalty  paid  to  the  owner  of  a  mineral 
right  by  the  operator  of  the  mine. 

Miners'  inch.  A  local  unit  for  the  measurement  of  water  supplied 
to  hydraulic  miners.  It  is  the  amount  of  water  flowing  under  a  cer- 
tain head  through  one  square  inch  of  the  total  section  of  a  certain 
opening  for  a  certain  number  of  hours  daily. 

Minium.     Protosesquioxide  of  lead. 

Mock  ore.     A  false  kind  of  mineral. 

Monkey  drift.     A  small  prospecting  drift. 

Monoclinal.  Applied  to  any  limited  portion  of  the  earth's  crust 
throughout  which  the  strata  dip  in  the  same  direction. 

Mountain  blue. .    Blue  copper  ore. 

Muffle.  A  semi-cylindrical  or  long-arched  oven,  usually  small 
and  made  of  fire  clay. 


328      prospector's  field-book  and  guide. 

Mundic.  Iron  pyrites,  called  so  in  Cornwall.  White  mundic  is 
mispickel. 

Nacreous.     Resembling  mother-of-pearl. 

Native.  Occurring  in  nature;  not  artificially  formed;  usually  ap- 
plied to  the  metals. 

Nickeliferous  or  Niccoliferous.     Containing  nickel. 

Nittings.     The  refuse  of  good  ore. 

Noble  metals.  The  metals  which  have  so  little  affinity  for  oxygen 
that  their  oxides  are  reduced  by  the  mere  application  of  heat  with- 
out a  reagent;  in  other  words,  the  metals  least  liable  to  oxidation 
under  ordinary  conditions.  The  list  includes  gold,  silver,  mercury, 
and  the  platinum  group. 

Nodule  or  Noddle.     A  small  round  mass. 

Nugget.     A  lump  of  native  metal,  especially  of  a  precious  metal. 

Nucleus.     A  body  about  which  anything  is  collected. 

Open  cut.     A  surface  working,  open  to  daylight. 

Ore.  A  natural  mineral  compound,  of  the  elements  of  which  one 
at  least  is  a  metal. 

Organic  Compounds.  Compounds  containing  carbon,  generally 
derived  from  animals  or  plants. 

Outcrop.  The  portion  of  a  vein  or  stratum  emerging  at  the  sur- 
face, or  appearing  immediately  under  the  soil  and  surface  debris. 

Output.     The  product  of  a  mine. 

Oxidation.     A  chemical  union  with  oxygen. 

Oxide.     The  combination  of  a  metal  with  oxygen. 

Pack  Walls.  Walls  built  of  loose  material  in  mines  to  support  the 
roof. 

Panning.  Washing  earth  or  crushed  rock  in  a  pan,  by  agitation 
with  water,  to  obtain  the  particles  of  greatest  specific  gravity  it  con- 
tains; chiefly  practiced  for  gold,  also  for  quicksilver,  diamonds  and 
other  gems. 

Parting.  The  separation  of  two  metals  in  an  alloy,  especially  the 
separation  of  gold  and  silver  by  means  of  nitric  or  sulphuric  acid. 

Pavement.     The  floor  of  a  mine. 


GLOSSARY    OF    TERMS.  329 

Pay-streak.  The  zone  in  a  vein  which  carries  the  profitable  or 
pay  ore. 

Peroxide.  An  oxide  containing  more  oxygen  than  some  other 
oxide  of  the  same  element. 

Peter  or  peter-out.     To  fail  gradually  in  size  or  quality. 

Petrified.     Changed  to  stone. 

Petrology.     Study  of  rocks. 

Phosphates.     Phosphoric  acid  combinations. 

Pinch.     To  contract  in  width. 

Pipe  or  pipe-vein.     An  ore-body  of  elongated  form. 

Piping.     Washing  gold  deposits  by  means  of  a  hose. 

Placer.  A  deposit  of  valuable  mineral,  found  in  particles  in  allu- 
vium or  diluvium,  or  beds  of  streams,  etc. 

Plasma.     A  green  variety  of  quartz. 

Plastic.     Easily  moulded. 

Plat.     The  map  of  a  survey  in  horizontal  projection. 

Plumbago.     Graphite  or  black  lead. 

Plumb  Bob.  A  weight  suspended  by  a  string  to  determine  vertical 
lines. 

Plush  Copper.     A  fibrous  red  copper  ore. 

Pocket.     A  small  body  of  ore. 

Porphyritic.     Of  the  nature  of  porphyry. 

Potstone.     Compact  steatite. 

Precipitate.  Term  applied  to  solid  matter  which  is  separated  from 
a  solution  by  the  addition  of  reagents  or  exposure  to  heat. 

Prill.     A  good  sized  piece  of  pure  ore. 

Prisms.  Solids  whose  bases  are  plane  figures,  and  whose  sides  are 
parallelograms. 

Pryan.     Ore  in  small  pebbles  mixed  with  clay. 

Pudding -Stone.     A  conglomerate  in  which  the  pebbles  are  rounded. 

Pulp-assay.  The  assay  of  samples  taken  from  the  pulp,  i.  e.,  pul- 
verized ore  and  water,  after  or  during  crushing. 

Putty  powder.     Crude  oxide  of  tin. 

Quarry.     An  open  or  day  working. 


330      prospector's  field-book  and  guide. 

Quartz.  Crystalline  silica ;  also,  any  hard  gold  or  silver  ore,  as 
distinguished  from  gravel  or  earth,  hence  quart-mining  as  dis- 
tinguished from  hydraulic  mining,  etc. 

Quartzose.     Containing  quartz  as  a  principal  ingredient. 

Quicksand.     Sand  which  is,  or  becomes,  upon  the  access  of  water, 

"quick,"  i.  e.,  shifting,  easily  movable  or  semi-liquid. 

Race.     A  small  thread  of  spar  or  ore. 

Radiating.     Diverging  from  a  centre. 

Mange.     A  mineral-bearing  belt  of  rocks. 

Ravine.     A  deep  narrow  valley. 

Reduce.  To  deprive  of  oxygen;  also,  in  general,  to  treat  metal- 
lurgically  for  the  production  of  metal. 

Refractory.     Kesisting  the  action  of  heat  and  chemical  agents. 

Reniform.     Kidney-like. 

Reticulated  Veins.     Veins  traversing  rocks  in  all  directions. 

Reverse  Faults.  Faults  due  to  thrust;  the  hanging-wall  side  of  the 
fault  being  forced  upwards  on  the  foot-wall. 

Rider.     See  Horse. 

Riffle.  A  groove  or  interstice,  or  a  cleat  or  block,  so  placed  as 
to  produce  the  same  effect,  in  the  bottom  of  a  sluice,  to  catch  free 
gold. 

Rim-rock.  The  bed-rock  rising  to  form  the  boundary  of  a  placer 
or  gravel  deposit. 

Rise.  That  portion  of  a  bed  or  coal-seam  which  lies  above  a  level 
is  said  to  be  "  to  the  rise." 

Roasting.     Calcination,  usually  with  oxidation. 

Rocker.  A  short  trough  in  which  auriferous  sands  are  agitated 
by  oscillation  in  water,  to  collect  their  gold. 

Rolley-way.     A  gangway. 

Roof.     The  strata  immediately  above  a  coal  seam. 

Rosette  copper.  Disks  of  copper,  red  from  the  presence  of  sub- 
oxide, formed  by  cooling  the  surface  of  melted  copper  through 
sprinkling  with  water. 

Royalty.  The  dues  of  a  lessor  or  landlord  of  a  mine,  or  of  the 
owner  of  a  patented  invention. 


GLOSSARY    OF    TERMS.  331 

Rusty  gold.  Free  gold  which  does  not  easily  amalgamate,  the 
particles  being  coated,  as  is  supposed,,  with  oxide  of  iron. 

Saccharoid.     Like  lump-sugar. 

Saddle.     An  anticlinal  in  a  bed  or  flat  vein. 

Sal  ammoniac.     Chloride  of  ammonium. 

Saline.     A  salt-spring  or  well;  salt  works. 

Sampling.  Mixing  ores  so  that  a  portion  taken  from  the  mixture 
may  fairly  represent  the  whole  body. 

Schist.     Crystalline  rock. 

Schorl.     Black  tourmaline. 

Seam.     A  stratum  or  bed  of  coal  or  other  mineral.  . 

Sectile.     Easily  cut. 

Sediment.     A  deposit  formed  by  water. 

Segregate.  To  separate  the  undivided  joint  ownership  of  a  mining 
claim  into  smaller  individual  ''segregated"  claims. 

Segregation.  A  mineral  deposit  formed  by  concentration  from  the 
adjacent  rock. 

Salvage  or  Selfedge.  A  layer  of  clay  or  decomposed  rock  along  a 
vein-wall. 

Shaft.     A  pit  sunk  from  the  surface. 

Shake.  A  cavern,  usually  in  limestone;  also  a  crack  in  a  block  of 
stone. 

Shale.     Consolidated  clay. 

Shift.  The  time  for  a  miner's  work  in  one  day;  also  the  gang  of 
men  working  for  that  period,  as  the  day-shift,  the  night-shift. 

Shingle.     Clean  gravel. 

Side-basset.     A  transverse  direction  to  the  line  of  dip  in  strata. 

Silicates.     Compounds  of  silica  or  silicic  acid  with  a  base. 

Siliceous.     Consisting  of  or  containing  silex  or  quartz. 

Sinter.     A  deposit  from  hot  springs. 

Slag.  The  vitreous  mass  separated  from  the  fused  metals  in  smelt- 
ing ores. 

Slate.     Indurated  clays,  sometimes  metamorphosed. 
Slickensides.    Polished  and  sometimes  striated  surfaces  on  the  walls 
of  a  vein,  or  on  interior  joints  of  the  vein-material  or  of  rock  masses. 


332      prospector's  field-book  and  guide. 

Slide.     A  fault  or  cross  course. 

Slime  ore.  Finely  crushed  ore  mixed  with  water  to  the  consistence 
of  mud  or  slime. 

Sline.     Natural  transverse  cleavage  of  rock. 

Slip.     A  vertical  dislocation  of  rocks. 

Slope.     An  inclined  opening  to  a  mine. 

Sluicing.     Washing  auriferous  earth  through  long  boxes  (sluices). 

Slums.     The  most  finely  crushed  ores. 

Spall  or  Spawl.  To  break  ore.  Pieces  of  ore  thus  broken  are 
called  spalls. 

Speiss  or  speise.  Impure  metallic  arsenides,  principally  of  iron, 
produced  in  copper  and  lead  smelting.  Cobalt  and  nickel  are  found 
concentrated  in  the  speiss  obtained  from  ores  containing  these  metals. 

Spoon.  An  instrument  made  of  an  ox  or  buffalo  horn,  in  which 
earth  or  pulp  may  be  delicately  tested  by  washing  to  detect  gold, 
amalgam,  etc. 

Spur.     A  branch  leaving  a  vein,  but  not  returning  to  it. 

Stalactites.  Icicle-like  incrustations  hanging  down  from  the  roof 
of  caves. 

Stalagmites.  Similar  to  stalactites,  but  formed  on  the  floor  of 
the  caves  by  the  deposition  of  solid  matter  held  in  solution  by  drop- 
ping water. 

Stannary.     A  tin  mine,  or  tin  works. 

Step-vein.  A  vein  alternately  cutting  through  the  strata  of  country- 
rock  and  running  parallel  with  them. 

Stockwork.  An  ore  deposit  of  such  a  form  that  it  is  worked  in 
floors  or  stories. 

Stope.     To  remove  the  ore. 

Stratum.     A  bed  or  layer. 

Streak.  The  powder  of  a  mineral,  or  the  mark  which  the  latter 
makes  when  rubbed  upon  a  harder  substance. 

Striated.     Marked  with  parallel  grooves  or  strice. 

Strike.  The  direction  of  a  horizontal  line  drawn  in  the  middle 
plane  of  a  vein  or  stratum  not  horizontal. 

String.     A  small  vein. 

Strip.  To  remove  from  a  quarry,  or  open  working,  the  overlying 
earth  and  disintegrated  or  barren  surface  rock. 


GLOSSARY    OF    TERMS.  333 

Stull.  A  platform  laid  on  timbers,  braced  across  a  working  from 
side  to  side,  to  support  workmen  or  to  carry  ore  or  waste. 

Sturt.     A  tribute-hdiYg&m  which  turns  out  profitable  for  the  miner. 

Sublimation.  The  volatilization  and  condensation  of  a  solid  sub- 
stance without  fusion. 

Submetallic.     Of  imperfect  metallic  lustre. 

Subsidence.     The  sinking  down  of. 

Subtransparent.     Of  imperfect  transparency. 

Sulphate.     A  salt  containing  sulphuric  acid. 

Sulphide.     A  combination  of  metal  with  sulphur. 

Sulphurets.  In  miners'  phrase,  the  undecomposed  metallic  ores, 
usually  sulphides.     Chiefly  applied  to  auriferous  pyrites. 

Synclinal.  The  axis  of  a  depression  of  the  strata;  also  the  depres- 
sion itself.    Opposed  to  anticlinal,  which  is  the  axis  of  an  elevation. 

Tailings.  The  lighter  and  sandy  portions  of  the  ore  on  a  buddle 
or  in  a  sluice. 

Tail-race.  The  channels  in  which  tailings,  suspended  in  water, 
are  conducted  away. 

Thermal.     Hot,  e.  g.,  thermal  springs. 

Throw.  A  dislocation  or  fault  of  a  vein  or  stratum,  which  has 
been  thrown  up  or  down  by  the  movement. 

Tinstone.     Ore  containing  small  grains  of  oxide  of  tin. 

Toadstone.     A  kind  of  trap-rock. 

Toughening.     Refining,  as  of  copper  or  gold. 

Translucent.     Allowing  light  to  pass  through,  yet  not  transparent. 

Trap.  In  miners'  parlance,  any  dark  igneous,  or  apparently 
igneous,  or  volcanic  rock. 

Trend.     The  course  of  a  vein. 

Tribute.     A  portion  of  ore  given  to  the  miner  for  his  labor. 

Trogue.     A  wooden  trough,  forming  a  drain. 

Trow.     A  wooden  channel  for  air  or  water. 

Tuff  or  Tufa.     A  soft  sandstone  or  calcareous  deposit. 

Tunnel.  A  nearly  horizontal  underground  passage,  open  at  both 
ends  to  day.     See  Adit. 

Turn.     A  pit  sunk  in  a  Drift. 


334      prospector's  fie,ld-book  and  guide. 

Underlay  or  Underlie.  The  departure  of  a  vein  or  stratum  from 
the  vertical,  usually  measured  in  horizontal  feet  per  fathom  of 
inclined  depth. 

Unstratified.     Not  arranged  in  strata. 
Upcast.     The  lifting  of  a  coal  seam  by  a  dike. 

Vanning.     Washing  "tin-stuff"  by  means  of  a  shovel. 

Vein.  See  Lode.  The  term  vein  is  also  sometimes  applied  to 
small  threads,  or  subordinate  features  of  a  larger  deposit. 

Vein  stuff.     Ore  associated  with  gangue. 

Vermilion.     Mercury  sulphide. 

Vitreous.     Glassy. 

Volatile.     Capable  of  easily  passing  off  as  vapor. 

Vug,  Vugg  or  Vugh.  A  cavity  in  the  rock,  usually  lined  with  a 
crystalline  incrustation.     See  Geode. 

Walls.  The  boundaries  of  a  lode,  the  upper  one  being  the 
'"  hanging,"  the  lower  the  "  foot  wall." 

Wash  Dirt.     Auriferous  gravel,  sand,  clay,  etc. 

Wastrel.     A  tract  of  waste  land,  or  any  waste  material. 

Weathering.  Changing  under  the  effect  of  continued  exposure  to 
atmospheric  agencies. 

Whim  or  Whimsey.  A  machine  for  hoisting  by  means  of  a  verti- 
cal drum,  revolved  by  horse  or  steam  power. 

White-damp.  A  poisonous  gas  sometimes  encountered  in  coal 
mines. 

Wild  lead.     Zinc  blende. 

Win.     To  extract  ore  or  coal. 

Wing  Dams.  Dams  built  from  the  side  of  a  river  with  the  object 
of  deflecting  it  from  its  course. 

Winze.     An  interior  shaft,  usually  connecting  two  levels. 

Working  home.     Working  toward  the  main  shaft  in  extracting  ore. 

Working  out.  Working  away  from  the  main  shaft  in  extracting 
ore. 

Zinc-scum.     The  zinc-silver  alloy  skimmed  from  the  surface  of  the 
bath  in  the  process  of  desilverization  of  lead  by  zinc. 
Zinc-white.     Oxide  of  zinc. 


INDEX, 


ACID,   nitric,    preparation   of, 
131,132 
Acidic  rocks,  185 
Acids,  12 
Actinolite,  8 
Adularia,  239 

Africa,  diamonds  in,  271,  272 
Agate,  3,  284 
Alabaster,  243 

Alaska,  burning  and  drifting  in, 
118,  119 

gold  in,  136-138 
Albite,  3 
Alloys,    estimation    of    gold   in, 

305-307 
Alluvial   claims,   estimating  the 

value  of.  41,  42 
Almaden,  Spain,  quicksilver  de- 
posits at,  204 
Almandine,  281 
Almandine  ruby,  277 
Alum,  231 

Alumina,  detection  of,  80 
Aluminite,  221 

Aluminous  schists  or  shales,  231 
Aluminium,  221-226 
Aluminium,     antimony,    manga- 
nese, 221-230 

minerals  as  sources  of,  221 
Amalgamating  assay,  120-122 
Amalgams,  202 

native,  203 
Amazon  stone,  239,  240 
Amethyst,  3,  286 

oriental,  225,  277 
Amphibole,  7,  8 
Amydolite,  27 

Analysis  of  ores  for  nickel  and 
cobalt,  209-216 

qualitative,  of  ores,  82-94 

wet  method  of,  79-94 

(335) 


Analyses  of  ores,  79 
Anglesite,  177 
Anorthite,  5 
Anthracite,  238 
Antimonite,  226,  227,  228 
Antimony,  226-228 

assay  of,  101,  102 

detection  of,  80 

glance,  226,  227,  228 
Apatite,  231-233 
Aqueous  rocks,  29-31 
Areas,  to  measure,  72-75 
Argentite,  149,  150 
Arsenic,  233,  234 

indication  of,  79 
Arsenical  pv rites,  196 
Asbestus,  8,"  11,  234 
Asbolite,  219 
Asphalt,  native,  264,  265 
Assay,  amalgamating,  120-122 

definition  of,  49,  50 

furnace,  94,  95 

furnace,    portable,    for  field 
testing,  95,  96 

of  antimony,  101,  102 

of  bismuth,  102 

of  cobalt,  102 

of  copper,  170-173 

of  copper  ore,  101 

of  galena,  101 

of  gold  and  silver  ores,  98- 
100 

of  gold  by  the  touchstone, 
304,  305 

of  lead  ore,  101 

of  manganese,  102 

of  mercury,  101 

of  nickel,  102 

of  tin  ore,  101,  181,  182 

of  zinc,  102 
Asterias,  225 


336 


INDEX. 


Augite,  9,  10 
Auriferous  lodes,  36,  37 
Australian  gold,  104,  105 
Aventurine,  239 
Avoirdupois  weight,  297 
Azoic  rock,  24 
Azurite,  165 

BANCA,  discovery  of  tin  in,  183 
Barium  sulphate,  234,  235 
Barytes,  234.  235 
Basalt,  27,  28 
Basanite,  3 
Bases,  12 
Bassets,  34 
Batea,  108 

Bauxite,  221,  222,  223 
Beds  and  layers,  34 
Bell  metal,  184 
Beryl,  270 

Billiton,  discovery  of  tin  in,  183 
Biotite,  6,  7,  31,  130,  245 
Bismuth,  205,  206 

assay  of,  102 

gold,  105 
Bitumen,  264,  265 

elastic,  263 
Bituminous  coal,  238 
Black  band  ore,  194,  195 

diamond   274 

gold,  105 

jack,  189,  190 

lead,  240-242 

mica,  245 

oxide  of  copper,  164,  165 

tellurium,  141,  142 
Blende,  189,  190 
Bloodstone,  285 
Blowing,  110 
Blow-pipe  and  its  uses,  46-58 

experiments,  53-58 

making  a,  from  a  glass  tube, 
52,  53 

manipulation  of  the,  48,  49 

practice,  chief  requirements 
for,  47 
reagents  for,  47,  48 

principal    means   of    testing 
minerals  before  the,  53 
Blue  carbonate  of  copper,  165 

ground,  272 


Blueite,  209 

Bog  iron,  occurrence  of,  44 

Bole,  237 

Borax,  47,  48,  235,  236 

blow-pipe  test  with,  53-55 
Boring.  308 

bars,  308 
Borneo,  diamonds  in,  270,  271 
Bornite,   165 
Brazil,  diamonds  in,  271 
British    weights    and    measures, 

basis  of,  295,  296 
Brittle  silver  ore,  151 
Bromic  silver,  152 
Bromyrite,  152 
Brown  coal,  238 

hematite,  193,  194 

iron  ore,  193,  194 
Burning  and  drifting,  118,  119 

pADMIUM,  220 
\J    Calcite,  hexagonal  crystal,  64 
Calamine,  188,  189 
California,  gold-bearing  beds  in, 
44 
Gulch,  Colorado,  section  of 
strata  in,  showing  portion 
of  carbonate  of  lead   de- 
posits, 176 
quicksilver-bearing  belt  of, 
204, 205 
Californian  gold,  104, 105 
Cannel  coal,  238 
Carbonate  of  lead,  176,  177 

deposits,    section 
of,  176  _ 
soda,  blow-pipe  test 
with,  55,  56 
preparation  of, 
47,48 
Carbonates,  detection  of,  81 
Carbuncle,  281 
Carnelian,  285 
Casing.  34 
Cassiterite,  182,  183 

occurrence  of,  in  the  United 
States,  184,  185 
Cat's  eye,  287 
Cement,  117 
Cerargyrite,  150,  151 
Cerussite,  176,  177 


INDEX. 


337 


Chalcedony,  3,  285 
Chalcocite,  162 

Chalcopyrite,  16,  163,  164,  208 
Chemical  elements,  rule  for  find- 
ing   the    propor- 
tional    parts    by 
weight  of,  311 
theirsymbols,equiv 
alents  and  specific 
gravities,  table  of, 
309,  310 
substances,    common    names 
of,  311,  312 
China  clay,  236,  237 
Chlorite,  10,  11 
Chlorospinel,  277 
Chromate  of  lead,  177,  178 
Chromic  iron  ore,  195 
Chromite,  195 
Chrysocolla.  164 
Chrysoprase,  285 
Chrysotile,  11 
Cinnabar,  203 
Cinnamon  stone,  281 
Citron  quartz,  286 
Clays,  236.  237 
Cleavage,  17 
Coal,  237,  238 
Cobalt,  217-220 

and  nickel  ores,  analysis  of, 
209-216 
separation  of,  215,  216 
assay  of,  102 
bloom,  219 
detection  of,  80 
geologv  of,  219,  220 
wad,  219 
Cobaltite,  218 
Colors,  accidental,  effect  of,  14 

of  minerals,  13-15 
Compass,  use  of,  in  searching  for 

ore,  200,  201 
Comstock  Lode,  extent  of,  155 

section  of,  154, 156 
Contact  deposits,  35 
Copper,  160-173 

assay  of,  170-173 
detection  of,  81 
examining  a  mineral  for.  169 
exploring  a  new  country  for, 
168,  169 


Copper,  geology  of,  166-170 

glance,  162 

in  an  ore,  to  obtain  the  per 
cent,  of,  170-173 

native,  properties  of,  160 
testing  of,  160,  161 

natural  combinations  of,  161 

nickel,  206,  207 

ore,  assay  of,  101 

ores,  weight  of,  169 

pyrites,  163,  164 

separation  of,  210 

world's  supply  of,  166 
Corundum,  221,  224-226 

and  emery,  224-226 
Country,  definition  of,  32 
Cradle,  111,  112 
Creeks,  wash  of,  as  a  guide  in 

prospecting,  38,  39 
Crocoite,  177,  178 
Crucible,  melting  ore  in  a,  99 
Crucibles,  94 
Cryolite,  221,  223,  224 
Crystalline  forms,  system  of,  59 
Crystallography,  59-69 

systems,  illustrations  of,  65, 
66 
Cube,  the,  60,  61 
Cupel,  94 
Cupellation,  98,  99 
Cuprite,  161,  162 

DARTON'S  gold  test,  122,  123 
Delfs,  34 
Deposit  of  economic  value,  first 

indications  of  a,  31,  32 
Deposits,  irregular,  35 

metalliferous  localities  of,  31, 

32 
superficial,  looking  for  indi- 
cations of,  43,  44 
surface,  35 
Diamond,  270-276 
black,  274 
colors  of,  273,  274 
drill,  308,  309 
natural  surface  of,  273 
power  of  refraction  of,  274 
specific  gravity  of,  274 
value  of,  275 
Diaspore,  221 


338 


INDEX. 


Dichroiscope,  use  of  the,  268-270 

Dip  of  a  lode,  32 

Dodecahedron,  61 

Dolerite,  27 

Dolly  Hide  Mine,  Md. ,  section 

of  copper  bed  at,  167 
Dolomite,  238 
Dry  assay  of  ores,  94-102 
Ductility,  20 

EAGLE  Vein,  Lake  Superior, 
section  of,  168 
Earth's  crust,  movements  of,  24, 

25 
Earthy  cobalt,  219 
Elastic  bitumen.  263 
Elasticity  and  flexibility,  19 
Elaterite,  263 
Electricity,  prospecting  by  means 

of,  293-295 
Emerald,  270 

nickel,  207 
Emery  and  corundum,  224-226 
Emma  Mine,  158 
English  length,  296 
Epidote,  282 
Erubiscite,  165 
Erythrite,  218,  219 
Eureka  Mines,  Nevada,  157 
Eye  agates,  284 

FALSE  topaz,  286 
Feldspar,  3-5,  239,  240 

Fire  lute,  102 

Fire  opal,  282 

Flames  of  a  sperm  candle,  49,  50 
il  lustration 
and  practice 
showing  the 
c  h  a  r  a  c  ter- 
istic  power  of 
either,  51, 52 

Flexibility  and  elasticity,  19 

Flint.  3,  240 

Float  gold,  118 

Florentine,  276 

Fluorite,  240 

Fluorspar,  240 

Foleyrite,  208 

Foliated  tellurium,  141,  142 

Formations,  definition  of,  33,  34 


Fracture,  17 
Franklinite,  192,  193 
French  measures,  301 

weight,  301 
Fuller's  earth,  237 
Fuming*  nitric  acid,  132 

GALENA,  assay  of,  101 
district  of  Wisconsin,  Il- 
linois and  Iowa,  order 
of  strata  in  the,  175 
geology  and  form  of  lodes 

of,  175 
limestones,  178,  179 
properties  of,  174 
test  for  silver  in,  174,  175 
Gap  Mine,  Lancaster  Co.,   Pa., 

nickel  in,  207,  217 
Garnet,  68,  69,  280,  281 
Garnierite,  217 

Gems  and  precious  stones,  266- 
292 
examination    of,    with     the 

dichroiscope,  268-270 
prospecting  for,  266,  267 
table   of    characteristics    of, 
290-292 
Gemstones  known  to  occur  in  the 
United  States,  list  of,  288, 
289  _ 
occurring  only  in  the  United 

States,  list  of,  289 
species  and  varieties  of,  not 
yet  identified  in  any  form, 
in  the  United  States,  289 
Geology,    mineralogy,     mining, 
prospecting,  etc  ,  glossary 
of  terms   used  in  connec- 
tion with,  315-334 
of  bismuth,  206 
of  cobalt,  219,  220 
of  copper,  166-170 
of  gold,  125-130 
of  iron,  196-198 
of  lead,  178-181 
of  manganese.  280 
of  silver  ores,  152-159 
of  zinc,  190,  191 
practical,  25-31 
Gibbsite.  221 
Girdles,  34 


INDEX. 


339 


Glance  coal,  238 
Glass  tubes,  tests  in,  57,  58 
Glossary  of  terms  used  in  connec- 
tion with  prospecting,  raining, 
mineralogy,  geology,  etc.,  315- 
334 
Gneiss,  28 
Gold.  103-140 

amalgam,  105,  124 
amalgamating  assav  of,  120- 

122 
assay  of,  by  the  touchstone, 

304,  305 
association  of,  with  iron,  124 
chief  supplies  of,  104 
color  of,  16,  106,  107 
crystallization  of,  105 
crystals,  105 
distribution  of,  103,  104 
dust,  105 

free,  in  drifts  and  sands,  128 
in  Alaska,  136-138 
in  alloys,  estimation  of,  305- 

307 
in  combination,  130-136 
in  metallic  sulphides,  sepa- 
ration of,  131-136 
in  pyrites,  detection  of,  105 
irregular  deposits  of,  127.128 
native,  constitution  of,  104 
determination  of,  79 
occurrence  of,  125 
nuggets,  105,  106 
occurrence  of,  104 

in     different 
forms,     123- 
125 
in  granitic  reg- 
ions, 126, 127 
in  quartz,  125 
of  the   Yukon   district,   de- 
rivation of,  137 
ores,  assay  of,  98-100 
original  position  of,  125,  126 
panning.  108-111 
placer,  39-41,  124 
properties  of,  107,  108 
quartz,  assaying  of,  100 
rule    for     ascertaining     the 
amount  of,  in  a  lump  of 
auriferous  quartz,  139, 140  | 


Gold,  section  showing  the  two 
conditions  under  which 
usually  found  in  rock  and 
drift,  127  ®^ 

standard  value  of,  in  differ- 
ent countries,  307 
test,  Darton's,  122,  123 
Grand  Duke  of  Tuscany,  276 
Granite,  29-31 
Granitic  regions,   gold  in,    126. 

127 
Graphic  granite.  30 

tellurium,  142,  143 
Graphite,  240-242 

test  for  the  purity  of,  242 
Gray  copper  ore,  162,  163 
Green  carbonate  of  copper,  165 

jade,  8 
Greenockite,  220 
Greenstone,  27 
Greisen,  186 
Guadalcazarite.  203 
Gypsum,  242,  243 

HAMMERS,  308 
Hard  bars,  44 
Hardness,  18,  19 

scale  of,  18,  19 
Harlequin  opal,  282,  283 
Heavy  spar,  234,  235 
Heights,  inaccessible,  to  measure, 

70-72 
Heliotrope.  285 
Hessian  crucibles,  94 
Hessite,  142 

Hexagonal  system,  62-64 
Horizons,  24 
Hornblende,  7,  8 
Horn  silver,  150,  151 
Hornstone,  3,  240 
Horse,  definition  of,  34 
Hydraulic  mining.  115-117 
Hydrogen,  apparatus  for  evolv- 
ing, 213,  214 
sulphide,  apparatus  for,  85- 
87 
Hyposyenite,  130 

IDRTA,   Austria,   cinnabar  at, 
204 
Igneous  rocks,  27,  28,  129 


340 


INDEX. 


India,  diamonds  in,  270 
Indicative  plants,  42,  43 
Infusorial  earth,  243 
Instruction,  preparatory,  1-45 
Iridium,  147 
Iron,  191-201 
alum,  231 

association  of  gold  with,  124 
geology  of,  196-198 
indication  of,  42 
meteoric.  68 
mode  of  obtaining  the  amount 

of,  in  an  ore,  96 
ores,    geologic    regions    of, 
197,  198 
of  Lake  Superior,  geo- 
logical      horizons 
around  the,  197 
pyrites,    16,   131-134,    195, 

196 
separation  of,  211 
sulphides,  gold  in,  130 
use   of    magnetic   needle  in 
prospecting  for,  1 98-201 
Ironstone  '•  blow  out,"  127 
Isometric  system,  59-61 
ltacolumite,  125 

JACINTH,  62 
Jack's  tin,  209 
Jade,  8 

Jamesonite,  178 
Jasper,  285 
Jasper  opal,  283 
Jet,  238 
Jumpers,  308 

KAOLIN,  236,  237 
Kermesite,  226 

Kimberley  mine,  diamond-bear- 
ing ground  of,  272 

Klondike  district.  Alaska,  136- 
138 

Koh-i-noor,  276 

Kunz,  George  F. ,  list  of  gem- 
stones,  known  to  occur  in  the 
United  States,  compiled  by, 
287-289 

LABKADOKITE,  4,  5 
Lake  George  diamonds,  286 


Lake    Superior    copper    region  y 

section   of   strata  in, 

168 

iron     ores,     geological 

horizons  around  the, 

•       197 

Lancaster  Co.,  Penna. ,  nickel  in, 

207 
Lapis  lazuli,  67 
Lazulite,  66 
Lead,  174-181 

and  tin,  174-187 
-antimony  ores.  178 
carbonate  of,  176.  177 
chief  sources  of,  in  the  United 

States,  180.  181 
chromate  of,  177,  178 
deposit  in  a  fissure  of  lime- 
stone, section  of.  181 
geology  of,  178-181 
indication  of,  42 
lode   in   micaceous   slate  in 
mine    near     Middletown, 
Conn.,  175 
mine,  circulation  of  water  in 

a,  180 
ochre,  178 
ore,  assay  of.  101 
phosphate  of,  177 
separation  of,  209,  210 
sulphate  of,  177 
Ledge,  32 
Length,  English,  296 

particular  measures  of,  296 
Lepidolite,  6,  7 
Lepidomelane,  7 
Licks,  247 
Lignite,  238  _ 
Lime,  detection  of,  80 
Limestone,  indication  of,  43 

lithographic,  243,  244 
Limonite,  193,  194 
Line,    ii.accessible,   to    measure, 

75-77 
Linnseite,  219 
Lithia  mica,  7 

Lithographic  limestone,  243,  244 
Loadstone,  191,  192 
Locating,  notice  of,  313,  314 
Lode,  examination  of  a,  44 
prospecting,  119 


INDEX. 


341 


Lodes,  32-34 

auriferous,  36,  37 
Long  torn,  112-114 
Lustre,  21 
Lydian  stone,  3 

MAGNESIA  alum,  231 
detection  of,  80 
Magnetic  iron  ore,  191,  192 

needle,  use  of,  in  prospecting 
for  iron,  198-201 
Magnetite,  191,  192 

occurrence  of,  44 
Malachite,  165 
Malleability,  20 
Manganese,  228-230 
assay  of,  102 
carbonate,  229,  230 
detection  of,  80 
geology  of,  230 
localities  of,  230 
occurrence  of,  44 
Massicot,  178 
Measures,  34 

and  weights,  295-304 
Meerschaum,  244 
Mercury,  202-205 

and  silver,  native  amalgams 

of,  203 
assay  of,  101 
bismuth,  nickel,  cobalt  and 

cadmium,  202-220 
detection  of,  81 
Metacinnabarite,  203 
Metallic  sulphides,  separation  of 

gold  in, 131-136 
Metalliferous   deposits,  localities 
of,  31,  32 
veins,  association  of  ore  in, 
45 
Metals,  native,  16 

specific  gravitv  of.  302,  303 
Metamorphic  rocks,  28,  29,  129 
Meteoric  iron,  68 
Mexico,  emerald  mine  in,  279 
Mica  schist,  *8,  29 
Micas,  5  7,  244,  245 
Michigan,  salt  in,  247 
Middletown,  Conn.,  lead  lode  in 
micaceous  slate  in  mine  near, 
175 


Milk  opal,  283 
Millerite,  207 
Mills,  power  of,  307,  308 
Mineral  coal,  237,  238 
definition  of  a,  2 
effect    of     intermixture     of 

coloring  matter  on  a,  14 
examining  a,  for  copper,  169 
test  of  the  hardness  of  a,  19 
tin-bearing,  testing  a,  181 
Mineralogy,     mining,      geology, 
prospecting,  etc.,  glossary 
of  terms  used  in  connec- 
tion with,  315-334 
special,  103-292 
technical,  1-25 
Minerals  associated  with  tin,  186 
basic,  12 
calculations  of  elements  in, 

11,  12 
chemical  tests  for,  46 
cleavage  of,  17 
colors  of,  13-15 
composition  of,  indicated  by 

their  forms,  59 
constituting  rocks,  3 
ductility  of,  20 
flexibility  and   elasticity  of, 

19 
fracture  of,  17 
lustre  of,  20 
malleability  of,  20 
naturally  colorless,  13 
of  common  occurrence,  spe- 
cific gravity  of,  302,  303 
phosphorescence  in,  15 
principal  means   of  testing, 

before  the  blow-pipe,  53 
properties  of,  2 
smell  of,  19,  20 
specific  gravity  of,  22 
streak  of.  17 
taste  of,  20 

tests  of,  in  glass  tubes,  57,  58 
various  useful,  231-251 
weight  and  form  of.  22,  23 
Miners'  superstitions,  37  , 

Mines.  34 

Mining,  hydraulic,  115-117 
Mining,     mineralogy,     geology, 
prospecting,    etc  ,    glossary   of 


342 


INDEX. 


terms  used  in  connection  with, 
315-334 
Mispickel,  147,  196 
Molybdenite,  245,  246 
Molybdenum,  245,  246 
Monoclinic  system,  65 
Moonstone,  239 
Moss  agate,  284 
Mountain  cork,  8 

leather,  8 

wood,  8 
Mud  volcanoes,  256 
Muffle,  94 
Muscovite,  5,  6,  31,  245 

NAGYAGLTE,  141,  142 
Native  amalgams,  203 
arsenic,  233 
asphalt,  264,  265 
Nephrite,  8 

Nevada,  rock  salt  in,  248 
New  Caledonia,  nickel  in,  217 
Nickel,  206-217 

and  cobalt  ores,  analysis  of, 
209-216 
separation  of,  215, 
216 
arsenide,  206,  207 
assay  of,  102 
detection  of.  80 
Niccolite,  206,  207 
Nitre,  246 

Nitric  acid,  preparation  of,  131, 
132 

OBSIDIAN,  28 
Octahedron,  61 
Oligoclaee,  3 
Onyx,  287 
Opal,  3,  282,  283 
Ore,  association  of,  in  metallifer- 
ous veins,  45 
copper,  assay  of,  101 
lead,  assay  of,  101 
mode      of      obtaining      the 
amount  of  iron  in  an,  69 
*       melting  of,  in  a  crucible,  99 
pulverization  of,  97 
tin,  assay  of,  101 
use  of  the  compass  in  search- 
ing for,  200,  201 


Ores,  analyses  of,  79-102 

dry  assav  of.  94-102 

gold,  assay  of,  98-100 

nickel   and   cobalt,  analysis 
of,  209-216 

preliminary  examination  of, 
79 

qualitative   analysis  of,  82- 
94 

silver,  assay  of,  98-100 

specific  gravity  of,  302.  303 
Oriental  amethyst,  225,  277 

jade,  8 

ruby,  225 

topaz,  225 
Orlof,  276 
Orpiment,  234 
Orthoclase,  3,  239 
Orthorhombic  system,  64,  65 
Osmium,  147 
Oxidizing  flame,  49 
Ozocerite,  261,  262 

PALLADIUM,  147 
Panning  out,  108-111 
Placer  deposits,  gold  in,  39,  41 
most  important,  137 
diggings,  character  of,  40,  41 
gold,  39-41,  124 
Placers,  39-41 
Plants,  indicative,  42,  43 
Plaster  of  Paris,  243 
Plastic  clay,  237 
Platinum,  143-147 

chemical  test  for,  145,  146 
Peacock  ore,  164 
Peat,  265 
Pelton  wheel,  rule  applicable  to, 

307,  308 
Petite  Anse  Island,  rock  salt  de- 
posit of,  247,  248 
Petroleum,  252  261 

bed-like  occurrence  of,  257 
indications  of,  253 
occurrence  of,  252 
ozocerite,  asphalt,  peat,  252- 

265 
prospecting  for,  252-261 
quality  of,  261 
vein-like  occurrence  of,  259, 
260 


INDEX. 


343 


Petroleum,  water  test  for,  254 

Petzite,  142 

Phenacite,  279,  280 

Phlogopite,  6 

Phosphate,  indication  of,  43 

of  lead,  177 

of  lime,  231-233 
Phosphorescence,  15 
Pilot  Knob,  Mo. ,  section  of,  198 
Pilot-stones,  39 
Pitt,  276 
Pleonast,  277 
Plumbago,  240-242 
Pockets,  35 
Polaric,  191,  192 
Polychroism,  15 
Porcelain  clay,  236,  237 
Porphyritic  granite,  30 
Potash  alum,  231 
Pot  holes,  44 
Pottery  clay,  237 
Power  for  mills,  307,  308 
Precious  stones  and  gems,   266- 

292 
Preparatory  instructions,  1-45 
Prism  compass,  use  of,  77,  78 

hexagonal,  63 
Prospecting  by   means  of    elec- 
tricity, 293-295 

color  of  the  rocks  as  a  guide 
in,  37,  38 

for  gems,  266,  267 

for  iron,  use  of  the  magnetic 
needle  in,  198-201 

for  petroleum,  252-261 

locality  for  starting,  36 

mining,  mineralogy  .geology, 
etc. ,  glossary  of  terms  used 
in  connection  with,  315- 
334 

of  lodes,  119 

wash  of  rivers  and  creeks  as 
a  guide  in,  38,  39 
Prospectors'  pointers,  313,  314 
Psilomelane,  229 
Pulverization  for  the  dry  method, 

97  y 

Pyrargyrite,  151,  152 
Pyrite,  16 
Pyrites,  arsenical,  196 

detection  of  gold  in,  105 


Pyrites,  estimating  the  available 
sulphur  in,  250 
iron,  195,  196 
Pyrolusite,  228,  229 
Pyromorphite,  177 
Pyropissite.  263 
Pyroxene,  9,  10 
Pyrrhotite,  208 

AUALITATIVE     analysis     of 
Y     ores,  82-94 
Quartz,  3 

auriferous,  rule  for  ascer- 
taining the  amount  of  gold 
in  a  lump  of,  139,  140 

crystals,  63 

limpid,  3 

occurrence  of  gold  in,  125 

rocks,  126 
Quicksilver,  202-205 

REALGAR,  233 
Ked  copper  ore,  161,  162 
hematite,  193 
oxide  of  zinc,  189 
silver  ore,  151,  152 
Reducing  flame,  49 
Reef,  32 
Regent,  276 
Resin  opal,  283 
Retinite,  263 
Retort,  making  a,  121 
Rhodocrosite,  229,  230 
Rhodium  gold,  105 
Riffle  box,  113 
Right-hand  theory,  37 
Rivers,   wash  of,   as  a  guide  in 

prospecting,  38,  39 
Roasting,  definition  of,  51 
JRock  and  drift,  section  showing 
the  two  conditions  under 
which     gold     is     usually 
found  in,  127 
azoic,  24 
boring  of,  308 
crystal,  286 
igneous,  23 
salt,  246-248 
Rocker,  111,  112 
Rocks,  acidic,  185 
aqueous,  29-31 


344 


INDEX. 


Rocks,  classification  of,  26 

color  of,  as  a  guide  to  the 

prospector,  37,  38 
definition  of,  2 
igneous,  27,  28,  1*29 
metamorphic,  28,  29,  129 
principal  constituents  of,  3 
specific  gravity  of,  302,  303 
volcanic,  27 

Rose  quartz,  286 

Rubicelle,  277 

Ruby,  277 

copper,  161, 162 
crystallization  of,  68,  69 
oriental,  225 
silver,  151,  152 

Ruby  Hill  mines,  158 

SALSES,  256 
Salt  deposits,  247 
licks,  247 

source  of  the  bulk  of,  in 
the  United  States,  248 
Saltpetre,  246 
Salts,  12 
Sandstone,  29 

examination  of,  81,  82 
oil-bearing,  254 
outcrops  of  oil  in,  257,  258 
Sapphire.  225.  276,  277 

crystallization  of,  68,  69 
Sard,  285 
Sardonyx,  287 
Satin  spar,  243 
Scale  of  hardness,  18,  19 
Scales,  96,  97 

Scranton,  W.  H. ,  on  indications 
from   the   magnetic   needle  in 
searching  for  ore,  199-201 
Scorifiers,  94 
Selenite,  243 

Selenium,  indication  of,  79 
Senarmontite,  226 
Sepiolite,  244 
Serpentine,  11 
Siberian  gold,  104,  105 
Siderite,  194 
Silicate  of  copper,  164 
Silicates,  13 
Sills,  34 
Silver,  147-159 


Silver  and  gold,  native  am  alga  mg 
of,  203 
and-  mercury,  native   amal- 
gams of,  203 
blow-pipe  test  of,  147 
chemical  test  for,  148 
glance,  149,  150 
indication  of,  43,  79 
in  galena,  test  for,  174,  175 
native,  appearance  of,  148 

determination  of,  79 
ores,  assay  of,  98-100 
geology  of,  152-159 
valuing  of,  152 
principal  source  of,  149 
sulphide,  151 
Slate,  249 
Sluices,  114,  115 
Smaltite,  206,  218 
Smell  of  minerals,  19,  20 
Smithsonite,  188 
Smoky  quartz,  286 
Soapstone,  250,  251 
Soda  alum,  231 

carbonate  of,  blow-pipe  teste 

with.  55,  56 

preparation  of, 

47,48 

Solid  measure,  297 

South  Africa,  diamonds  in,  271, 

272 
Sparta,  N.  J.,  zinc  mine,  section 

of  strata  near,  190 
Spathic  iron  ore,  194 
Specific  gravity,  20 

how  to  find,  299,  300 
of  metals,  ores,  rocks, 

etc.,  302.  303 
weight  by,  297-299 
Specular  ore,  193 
Sperm  candle  flame,  colors  of  a, 

49,  50 
Sphalerite,  189,  190 
Stannous    chloride,    preparation 

of,  146,  147 
Steatite,  250,  251 
Stephanite,  151 
Sterling    Iron     Mines,    N.    Y.„ 

nickel  at  the,  207 
Stibnite,  226,  227,  228 
Stone  coal,  238 


INDEX, 


345 


Strata,  34 

Streak,  17,  18 

Stream  tin,  182 

Strike  of  a  lode,  32 

Sudburv,    Canada,     sources     of 

nickel  in,  208 
Sulphate  of  lead,  177 
Sulphide  of  tin,  184 

of  zinc,  189,  190 
Sulphur,  249,  250 

indication  of,  79 
Sunstone,  239 
Surface  deposits,  35 

measure,  296,  297 
Surveying,  70-78 
Swampy  puddles,  prospecting  of, 

for  oil,  255,  256 
Syenite  granite,  30,  129 
Sylvanite,  142,  143 

TABLE  of  association  of  ore  in 
metalliferous  veins,  45 
of  characteristics   of   gems, 

290-292 
of  chemical  elements,   their 
symbols,  equivalents  and 
specific  gravities,  309,  310 
of  common  names  of  chemi- 
cal substances.  311,  312 
Tailings,  42 
Talc,  11,  250,  251 
Taste  of  minerals,  20 
Technical  mineralogy,  1-25 
Tellurides,  143 
Tellurium,  141 

platinum,  silver,  141-159 
Tetragonal  svstem,  61,  62 
Tetrahedrite,  162,  163 
Ticonderoga,    N.    Y. ,    graphite 

beds  at,  241 
Tin,  181-187 

-bearing  mineral,  testing  a, 

181 
detection  of,  80 
granites,  186 

minerals  associated  with,  186 
ore,  assay  of,  101,  181,  182 
pyrites,  184 
stone,  182,  183 
Titanium,  detection  of,  81 
Toad-eye  tin,  182 


Topaz,  278 

crystallization  of,  67 

false,  286 

localities  of,  67 
'"^oriental,  225 
Touchstone.  3 

assay  of  gold  by  the,  304,  305 
Tourmaline,  281,  282 
Trachyte,  27 
Traps,  27 
Tremolite,  8 
Triclinic  system,  65 
Troy  weight,  297 
Tungstate  of  soda,  187 
TurquoiS,  66,  283,  284 

localities  of,  69 

UNDERLIE,  32 
United  States,  list  of  gem- 
stones  known  to 
occur   in,   288 , 
289 
localities  of  agate 
in,  284 
of     beryl      or 
emerald    in, 
279 
of  diamonds  in 

273 
of   epidote   in, 

282 
of    garnet    in, 

281 
of  lazulite   in, 

66 
of  opal  in,  283 
ofphenacitein, 

280 
of  sapphires  in, 

277 
of  topaz  in  67, 

278 
of    tourmaline 

in,  282  > 
of  turquois  in, 
283,  284 
Ural  Mountains,  structure  of  the, 

127 
Uranium;  detection  of,  81 
Useful    minerals,    various,    231- 
251 


346 


INDEX. 


VABIEGATED  copper  pyrites, 
165 
Vitreous  copper,  162 
Volcanic  rocks,  27 

WAD,  228 
Wash,  definition  of,  38 
Water    courses,   prospecting   of, 
for  oil,  254,  255 
test  for  petroleum,  254 
weight  of,  300 
Weighing,  96,  97 
Weight  by  specific  gravity,  297- 

299 
Weights  and  measures,  295-304 

special,  300 
Wet  method  of  analysis,  79-94 
Whartonite,  208,  209 
White  jade,  8 
mica,  245 
Willemite,  189 


Witherite,  235 
Wolframite,  187 
Wood  opal,  283 
tin,  182 

YELLOW  ground,  272 
quartz,   286 
Yukon  district,  derivation  of  the 
gold  of,  137 

ZINC,  188-191 
and  iron,  188-201 
assay  of,  102 
carbonate,  188 
detection  of,  80 
geology  of,  190,  191 
indication  of,  43 
mine,  Sparta,  N,  J.,  section 
of  strata  near,  190 
Zincite.  189 
Zircon,  62 


Prospector's  Collection  Mo.  25. 


120  specimens,  averaging  2%  by  2  inches,  arranged  in  pasteboard  trays.  All 
compactly  held  in  small  cabinet  of  finest  workmanship.  Interior  of  drawers 
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knobs.  The  collection  is  conveniently  arranged  for  reference,  each  speci- 
men being  labeled  and  numbered  to  correspond  to  the  following  list.  Only 
typical  specimens  are  selected,  with  a  view  to  furnishing  the  most  character- 
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STANDARD 

COLLECTION  OF  ORES 


REQUIRED  FOR 


OSBORN'S  PROSPECTOR'S  FIELD  BOOK  AND  GUIDE. 

An  i?idisp  ens  able  aid  and  guide  to  users  of  this  book. 


GOLD. 

1.  Gold,  native,  in  quartz. 

2.  "         "         dust. 

3.  "     ore,  pyritiferous,  conglom. 

4.  "        "    telluride. 

SILVER. 

5.  Native  sihTer,  in  quartz. 

6.  Argentite,  glance. 

7.  Stephanite.  brittle  silver. 

8.  Cerargyrite,  horn        " 

9.  Pyrargyrite,  ruby       " 

COPPER. 

10.  Copper,  native. 

11.  Cuprite,  red  oxide. 

12.  Chalcocite,  copper  glance. 

13.  Tetrahedrite,  gray  copper. 

14.  Chalcopyrite.  copper  pyrites. 

15.  Chrysocolla,  silicate. 

16.  Melacouite,  black  oxide. 

17.  Malachite,  green  carbonate. 

18.  Azurite,  blue  carbonate. 

19.  Bornite,  variegated  pyrites. 

LEAD. 

20.  Galena,  sulphide,  cubic. 

21.  "        granular,  argentiferous. 

22.  Cerrusite,  carbonate,  gray. 

23.  "  "  white  cryst. 

24.  Anglesite,  sulphate. 

25.  Pyromorphite,  phosphate. 

26.  Crocoite,  chromate. 

27.  Jamesonite. 

TIN,  TUNGSTEN,  ETC. 

28.  Cassiterite,  tin  oxide  cryst'd 

29.  '•        "      in  greisen. 

30.  "        "      massive. 

31.  '•  "        "      stream  tin. 

32.  Stannite,  sulphide. 

33.  Wolframite. 

34.  Platinum,  native  grains. 

ZINC. 

35.  Smithsonite.  carbonate. 

36.  Calamine,  silicate. 

37.  Willemite. 

38.  Zincite,  oxide. 

39.  Sphalerite,  sulphide. 

IRON. 

40.  Iron,  meteoric. 

41.  Magnetite,  oxide,  granular. 

42.  "         lodestone. 

43.  Franklinite. 

44.  Hematite  cryst'd. 

45.  "  specular  ore. 


46.  Limonlte,  brown  ore. 

47.  Siderite,  spathic     " 

48.  Chromite,  chromic  ore. 

49.  Pyrite,  sulphide,  cryst'd. 

50.  "  "  massive. 

51.  Arsenopyrite,  mispickel. 

MERCURY,  ETC. 

52.  Cinnabar,  mercury  sulphide. 

53.  Bismuth,  native. 

NICKEL  AND  COBALT. 

54.  Niccnlite,  nickel  arsenide. 

55.  Zaratite,  Emerald  nickel. 

56.  Millerite,  nickel  sulphide. 

57.  Pyrrhotite,  niccoliferous  pyrite. 

58.  (iarnierite,  nickel  silicate.* 

59.  Cobaltite,  sulph-arsenide. 

60.  Asbolite,  cobalt  oxide. 

fll.  Smaltite,  Co.  and  Ni.  arsenide. 
ALUMINIUM  AND  ANTIMONY. 

62.  Bauxite,  hydrate. 

63.  Cryolite,  fluoride. 

64.  Corundum,  gray  cryst'd,  oxide. 

65.  "  emery,  black,     " 

66.  Stibnite,  antimony  sulphide. 

MANGANESE. 

67.  Wad,  bog  manganese. 

68.  Pyrolusite,  oxide. 

69.  Psilomelane,    " 

70.  Rhodochrosite,  carbonate. 

OTHER  USEFUL  MINERALS. 

71.  Apatite,  hexagonal,  cryst'd. 
72  "        phosphate-rock. 

73.  Arsenic,  native. 

74.  Realgar,  red  arsenic  sulphide. 

75.  Orpiment,  yellow    arsenic     sul- 

phide'. 

76.  Asbestns. 

77.  Barite,  orthorhombic,  cryst'd. 

78.  "     massive,  barium  sulphate. 

79.  Witherite,  barium  carbonate. 
i-0.  Anthracite  coal. 

81.  Bituminous    " 

82.  Cannel  coal. 

83.  Dolomite,  rhombohedral. 

84.  "         massive. 

85.  Orthoclase,  feldspar,  monoclinic. 

86.  "  "        cleavage. 

87.  Microcline,  Amazon-stone,  tricl. 

88.  Quartz  var.  rock  crystal,  hex. 

89.  "         •'     flint. 

90.  Fluorite,  cubic. 

91.  "        massive. 

92.  Calcite,  cleavage  rhomb. 


93.  Graphite,  plumbago. 

94.  Gypsum,  Selenite  cryst.,  mouoc. 

95.  *    "        Alabaster. 

96.  ' '       granular. 

97.  Infusorial  earth. 

98.  Lithographic  limestone. 
y9.  Meerschaum. 

100.  Biotite,  black  mica. 

101.  Muscovite,  white  mica. 

102.  Molybdenite. 

103.  Nitre. 

104.  Halite,  rock  salt. 

105.  Sulphur,  native. 

106.  Alunite,  alum  stone. 

107.  Talc,  soapstone. 

108.  Petroleum. 


109.  Ozocerite. 

110.  Elaterite,  elastic  bitumen. 

111.  Asphaltum. 

PRECIOUS  AND  SEMI-PRECIOUS 

STONES. 

112.  Diamond. 

113.  Sapphire. 

114.  Topaz. 

115.  Emerald. 

116.  Tourmaline. 

117.  Garnet. 

118.  Opal,  noble. 

119.  Turquois. 

120.  Amethyst. 


This  list  includes  all  important  minerals  mentioned  in  the  text,  besides 
illustrating  the  Scale  of  Hardness  and  the  six  systems  of  Crystallization. 

in  selecting  specimens  from  our  large  stock,  a  collection  is  secured  which 
represents,  in  a  brief  way,  the  varieties  with  which  the  prospector  or  miner 
is  most  likely  to  meet,  and  it  has,  therefore,  a  thoroughly  practical  value. 
Every  specimen  is  accurately  labeled  with  name  and  chemical  composition, 
and  numbered  to  correspond  to  above  list. 

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No.  23a.  Prospector's  Collection.  $64.00.  120  specimens,  averaging 
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No.  23.  Prospector's  Collection.  $16.00.  120  specimens,  averaging 
2%x2  inches.  Handsome  quartered  oak  case,  three  drawers,  fitted  with 
pasteboard  trays,  $10.00  extra.    (See  illustration.) 


The  following  items  are  selected  from  our  "  Collection  Catalog  "  as  of  in- 
terest to  the  prospector.  These  are  sold  in  the  size  4%x3%  inch  specimens  at 
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Includes  all  of  the  minerals  most  commonly  found  with  valuable  ores. 

No.  48.    Collection  Of  Rocks.    $6.00.    60  specimens,  averaging  2%x2  in. 

No.  34b.   Gold  and  Silver  Ores.    25  specimens,  averaging  2%x2  in.,  $25.00. 

Also  larger  series  illustrating  the  occurrence  of  Iron,  Lead,  Copper,  Zinc, 
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Sample  pages  inn.)  t 


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kSHTON. — The  Theory  and  Practice  of  the  Art  of  Designing 
Fancy  Cotton  and  Woollen  Cloths  from  Sample : 

Giving  full  instructions  for  reducing  drafts,  as  well  as  the  methods  of 
spooling  and  making  out  harness  for  cross  drafts  and  finding  any  re- 
quired reed;  with  calculations  and  tables  of  yarn.  By  Frederic  T. 
Ashton,  Designer,  West  Pittsfield,  Mass.  With  fifty-two  illustrations. 
One  vol.  folio  $5.00 

ASKINSON. — Perfumes  and  their  Preparation: 

A  Comprehensive  Treatise  on  Perfumery,  containing  Complete 
Directions  for  Making  Handkerchief  Perfumes,  Smelling-Salts, 
Sachets,  Fumigating  Pastils ;  Preparations  for  the  Care  of  the  Skin, 
the  Mouth,  the  Hair;  Cosmetics,  Hair  Dyes,  and  other  Toilet 
Articles.  By  G.  W.  Askinson.  Translated  from  the  German  by  IsiDOR 
Furst.    Revised  by  Charles  Rice.    32  Illustrations.    8vo.      $3.00 

BRONGNIART.— Coloring  and  Decoration  of  Ceramic  Ware. 
8vo $2.00 

BAIRD. — The  American  Cotton  Spinner,  and  Manager's  and 
Carder's  Guide: 

A  Practical  Treatise  on  Cotton  Spinning ;  giving  the  Dimensions  and 
Speed  of  Machinery,  Draught  and  Twist  Calculations,  etc. ;  with 
notices  of  recent  Improvements :  together  with  Rules  and  Examples 
for  making  changes  in  the  sizes  and  numbers  of  Roving  and  Yarn. 
Compiled  from  the  papers  of  the  late  Robert  H.  Baird.     iano. 

$1*0 


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3AIR.D.— Standard  Wages  Computing  Tables: 

An  Improvement  in  all  former  Methods  of  Computation,  so  arrange^ 
that  wages  for  days,  hours,  or  fractions  of  hours,  at  a  specified  rate 
per  day  or  hour,  may  be  ascertained  at  a  glance.  By  T.  Spangler 
Baird.     Oblong  folio        .         .         .         .         .         .         .         $5.00 

BAKER. — Long-Span  Railway  Bridges: 
Comprising    Investigations    of    the    Comparative    Theoretical    and 
Practical   Advantages   of  the  various  Adopted    or    Proposed    Type 
Systems  of  Construction;  with  numerous  Formulae  and  Tables.     By 
B.  Baker.     121110.  $1.00 

BAKER. — The  Mathematical  Theory  of  the  Steam-Engine: 
With  Rules  at  length,  and  Examples  worked  out  for  the  use  of 
Practical   Men.     By  T.   Baker,   C.    E.,  with  numerous  Diagrams. 
Sixth  Edition,  Revised  by  Prof.  J.  R.  Young.     i2mo.         .  75 

BARLOW. — The  History  and  Principles  of  Weaving,  by 
Hand  and  by  Power : 
Reprinted,  with  Considerable  Additions,  from  "  Engineering,"  with 
a  chapter  on  Lace-making  Machinery,  reprinted  from  the  Journal  of 
the  "Society  of  Arts."  By  Alfred  Barlow.  With  several  hundred 
illustrations.     8vo.,  443  pages  (Scarce.) 

BARR. — A  Practical  Treatise  on  the  Combustion  of  Coal: 
Including  descriptions  of  various  mechanical  devices  for  the  Eco- 
nomic Generation  of  Heat  by  the  Combustion  of  Fuel,  whether  solid, 
liquid  or  gaseous.    8vo.     .......         $2.50 

BARR. — A  Practical  Treatise  on  High  Pressure  Steam  Boilers : 
Including  Results  of  Recent  Experimental  Tests  of  Boiler  Materials, 
together  with  a  Description  of  Approved  Safety  Apparatus,  Steam 
Pumps,  Injectors  and  Economizers  in  actual  use.  By  Wm.  M.  Barr. 
204  Illustrations.     8vo.      .......         $3.00 

8AUERMAN.— A  Treatise  on  the  Metallurgy  of  Iron  : 
Containing  Outlines  of  the  History  of  Iron  Manufacture,  Methods  of 
Assay,  and  Analysis  of  Iron  Ores,  Processes  of  Manufacture  of  Iron 
and  Steel,  etc.,  etc.  By  H.  Bauerman,  F.  G.  S.,  Associate  of  the 
Royal  School  of  Mines.  Fifth  Edition,  Revised  and  Enlarged. 
Illustrated  with  numerous  Wood  Engravings  from  Drawings  by  J.  B. 
Jordan.     i2mo $2.oc 

BRANNT.— The  Metallic  Alloys:  A  Practical  Guide 

For  the  Manufacture  of  all  kinds  of  Alloys,  Amalgams,  and  Solders, 
used  by  Metal- Workers;  together  with  their  Chemical  and  Physical 
Properties  and  their  Application  in  the  Arts  and  the  Industries;,  with 
an  Appendix  on  the  Coloring  of  Alloys  and  the  Recovery  of  Waste 
Metals.  By  William  T.  Brannt.  34  Engravings.  A  New,  Re- 
vised, and  Enlarged  Edition.     554  pages.     8vo.        .         .         $4.50 

BEANS.— A   Treatise   on   Railway  Curves    and   Location  of 
Railroads : 
By  E.  W.  Beans,  C.  E.     Illustrated.     i2mo.    Tucks        .         $1.50 

BECKETT.— A  Rudimentary  Treatise  on  Clocks,  and  Watches 

and  Bells  : 

By  Sir  Edmund  Beckett,  Bart.,  LL.  D.,  Q.  C.  F.  R.  A.  S.     With 

numerous   illustrations.      Seventh  Edition,  Revised  and    Enlarged. 

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BELL. — Carpentry  Made  Easy: 

Or,  The  Science  and  Art  of  Framing  on  a  New  and  Improved 
System.  With  Specific  Instructions  for  Building  Balloon  Frames,  Bam 
Frames,  Mill  Frames,  Warehouses,  Church  Spires,  etc.  Comprising 
also  a  System  of  Bridge  Building,  with  Bills,  Estimates  of  Cost,  and 
valuable  Tables.  Illustrated  by  forty-four  plates,  comprising  nearly 
200  figures.  By  William  E.  Bell,  Architect  and  Practical  Builder. 
8vo $5.00 

BEMROSE. — Fret-Cutting  and  Perforated  Carving: 

With  fifty-three  practical  illustrations.  By  W.  Bemrose,  Jr.  I  vol. 
quarto $2.S9 

BEMROSE. — Manual  of  Buhl-work  and  Marquetry: 

With  Practical  Instructions  for  Learners,  and  ninety  colored  designs. 
By  W.  Bemrose,  Jr.     i  vol.  quarto  ....         $3.00 

BEMROSE.— Manual  of  Wood  Carving: 

With  Practical  Illustrations  for  Learners  of  the  Art,  and  Original  and 
Selected  Designs.  By  William  Bemrose,  Jr.  With  an  Intro- 
duction by  Llewellyn  Jewitt,  F.  S.  A.,  etc.  With  128  illustra- 
tions, 4to. $2.50 

BILLINGS.— Tobacco : 

Its  History,  Variety,  Culture,  Manufacture,  Commerce,  and  Various 
Modes  of  Use.  By  E.  R.  Billings.  Illustrated  by  nearly  200 
engravings.     8vo $3-oo 

BIRD. — The  American  Practical  Dyers'  Companion: 
Comprising  a  Description  of  the  Principal  Dye-Stuffs  and  Chemicals 
used  in  Dyeing,  their  Natures  and  Uses ;  Mordants,  and  How  Made ; 
with  the  best  American,  English,  French  and  German  processes  for 
Bleaching  and  Dyeing  Silk,  Wool,  Cotton,  Linen,  Flannel,  Felt, 
Dress  Goods,  Mixed  and  Hosiery  Yarns,  Feathers,  Grass,  Felt,  Fur, 
Wool,  and  Straw  Hats,  Jute  Yarn,  Vegetable  Ivory,  Mats,.  Skins, 
Furs,  Leather,  etc.,  etc.  By  Wood,  Aniline,  and  other  Processes, 
together  with  Remarks  on  Finishing  Agents,  and  Instructions  in  the 
Finishing  of  Fabrics,  Substitutes  for  Indigo,  Water-Proofing  of 
Materials,  Tests  and  Purification  of  Water,  Manufacture  of  Aniline 
and  other  New  Dye  Wares,  Harmonizing  Colors,  etc.,  etc. ;  embrac- 
ing in  all  over  800  Receipts  for  Colors  and  Shades,  accompanied  by 
170  Dyed  Samples  of  Raw  Materials  and  Fabrics.  By  F.  J.  Bird, 
Practical  Dyer,  Author  of  "  The  Dyers'  Hand-Book/'    8vo.     \-$7.$Q 

BLINN. — A  Practical  Workshop  Companion  for  Tin,  Sheet- 
Iron,  and  Copper-plate  Workers  : 
Containing  Rules  for  describing  various  kinds  of  Patterns  used  by 
Tin,  Sheet-Iron  and  Copperplate  Workers;  Practical  Geometry; 
Mensuration  of  Surfaces  and  Solids ;  Tables  of  the  Weights  of 
Metals,  Lead-pipe,  etc. ;  Tables  of  Areas  and  Circumference! 
of  Circles ;  Japan,  Varnishes,  Lackers,  Cements,  Compositions,  etc., 
etc.  By  Leroy  J.  Blinn,  Master  Mechanic.  With  One  Hundred 
and  Seventy  Illustrations.     i2mo.    .       0         .         .  #2.50 


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BOOTH.— Marble  Worker's  Manual: 

Containing  Practical  Information  respecting  Marbles  in  general,  theii 
Cutting,  Working  and  Polishing ;  Veneering  of  Marble  ;  Mosaics ; 
Composition  and  Use  of  Artificial  Marble,  Stuccos,  Cements,  Receipts, 
Secrets,  etc.,  etc.  Translated  from  the  French  by  M.  L.  Booth. 
With  an  Appendix  concerning  American  Marbles.  i2mo.,  cloth  $1.50 
BOOTH  and  MORFIT. — The  Encyclopaedia  of  Chemistry, 
Practical  and  Theoretical : 
Embracing  its  application  to  the  Arts,  Metallurgy,  Mineralogy, 
Geology,  Medicine  and  Pharmacy.  By  James  C.  Booth,  Melter 
and  Refiner  in  the  United  States  Mint,  Professor  of  Applied  Chem- 
istry in  the  Franklin  Institute,  etc.,  assisted  by  Campbell  Morfit, 
author  of  "  Chemical  Manipulations,"  etc.  Seventh  Edition.  Com- 
plete in  one  volume,  royal  8vo.,  978  pages,  with  numerous  wood-cuts 
and  other  illustrations ,,  (Scarce.) 

BRAM WELL.— The  Wool  Carder's  Vade-Mecum* 

A  Complete  Manual  of  the  Art  of  Carding  Textile  Fabrics.  By  W. 
C.  Bramwell.  Third  Edition,  revised  and  enlarged.  Illustrated. 
Pp.  400.     l2mo #2.50 

BRANNT.— A  Practical  Treatise  on  Animal  and  Vegetable 
Fats  and  Oils  : 
Comprising  both  Fixed  and  Volatile  Oils,  their  Physical  and  Chem- 
ical Properties  and  Uses,  the  Manner  of  Extracting  and  Refining 
them,  and  Practical  Rules  for  Testing  them;  as  well  as  the  Manufac- 
ture of  Artificial  Butter  and  Lubricants,  etc.,  with  lists  of  American 
Patents  relating  to  the  Extraction,  Rendering,  Refining,  Decomposing, 
and  Bleaching  of  Fats  and  Oils.  By  William  T.  Brannt,  Editor 
of  the  "  Techno-Chemical  Receipt  Book."  Second  Edition,  Revised 
and  in  a  great  part  Rewritten.  Illustrated  by  302  Engravings.  In 
Two  Volumes.     1304  pp.     8vo #10.00 

BRANNT.— A  Practical  Treatise  on  the  Manufacture  of  Soap 
and  Candles : 
Based  upon  the  most  Recent  Experiences  in  the  Practice  and  Science ; 
comprising  the  Chemistry,  Raw  Materials,  Machinery,  and  Utensils 
and  Various  Processes  of  Manufacture,  including  a  great  variety  of 
formulas.  Edited  chiefly  from  the  German  of  Dr.  C.  Deite,  A. 
Engelhardt,  Dr.  C.  Schaedler  and  others;  with  additions  and  lists 
of  American  Patents  relating  to  these  subjects.  By  Wm.  T.  Brannt. 
Illustrated  by  163  engravings.     677  pages.     8vo.      .         .         #7.50 

BRANNT.— India  Rubber,  Gutta  Percha  and  Balata : 

Occurrence,  Geographical  Distribution,  and  Cultivation,  Obtaining 
and  Preparing  the  Raw  Materials,  Modes  of  Working  and  Utilizing 
them,  Including  Washing,  Maceration,  Mixing,  Vulcanizing,  Rubber 
and  Gutta-Percha  Compounds,  Utilization  of  Waste,  etc.  By  Will- 
iam T.  Brannt.     Illustrated.     i2mo.    (1900.)         .        .        $3.00 


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BRANNT- WAHL- The  Techno-Chemical  Receipt  Books 

Containing  several  thousand  Receipts  covering  the  latest,  most  .m 
portant,  and  most  useful  discoveries  in  Chemical  Technology,  anc 
their  Practical  Application  in  the  Arts  and  the  Industries.  Editec 
ihiefly  from  the  German  of  Drs.  Winckler,  Eisner,  Heintze,  Mier 
zinski,  Jacobsen,  Roller,  and  Heinzerling,  with  additions  by  Wm.  1. 
Brannt  and  Wm.  H.  Wahl,  Ph.  D.  illustrated  by  78  engravings. 
J2mo.     495  pages     .         .  $2.o<3 

BROWN. — Five  Hundred  and  Seven  Mechanical  Movements: 
Embracing  all  those  which  are  most  important  in  Dynamics,  Hy- 
draulics, Hydrostatics,  Pneumatics,  Steam-Engines,  Mill  and  other 
Gearing,  Presses,  Horology  and  Miscellaneous  Machinery;  and  in- 
cluding many  movements  never  before  published,  and  several  of 
which  have  only  recently  come  into  use.  By  Henry  T.  Brown, 
i2mo $i.oo 

BUCKMASTER.— The  Elements  of  Mechanical  Physics: 
By  J.   C.   Buckmaster.       Illustrated    with    numerous    engravings. 
i2mo $1.00 

9ULLOCK.— The  American  Cottage  Builder  : 
A  Series  of  Designs,  Plans  and  Specifications,  from  $200  to  $20,000, 
for  Homes  for  the  People ;  together  with  Warming,  Ventilation, 
Drainage,  Painting  and  Landscape  Gardening.  By  John  Bullock, 
Architect  and  Editor  of  "  The  Rudiments  of  Architecture  and 
Building,"  etc.,  etc.     Illustrated  by  75  engravings.     8vo.  #2.50 

BULLOCK.— The  Rudiments  of  Architecture  and  Building: 
For  the  use  of  Architects,   Builders,   Draughtsmen,   Machinists,  En- 
gineers and  Mechanics.     Edited  by  John  Bullock,  author  of  "  The 
American  Cottage  Builder."  Illustrated  by  250  Engravings.  8vo.  $2.50 

BURGH.— Practical    Rules    for    the    Proportions   of     Modern 
Engines  and  Boilers  for  Land  and  Marine  Purposes. 
By  N.  P.  Burgh,  Engineer.     i2mo.  ....         $1.50 

BYLES.— Sophisms    of     Free    Trade    and    Popular    Political 

Economy  Examined. 

By  a  Barrister  (Sir  John  Barnard  Byles,  Judge  of  Common 

Pleas).       From  the    Ninth    English   Edition,  as    published    by    the 

Manchester  Reciprocity  Association.      i2mo.      .         .         .         #1.25 

BO  WM  AN. —The  Structure  of  the  Wool  Fibre  in  its  Relation 
to  the  Use  of  Wool  for  Technical  Purposes  : 
Being  the  substance,  with  additions,  of  Five  Lectures,  delivered  at 
the  request  of  the  Council,  to  the  members  of  the  Bradford  Technical 
College,  and  the  Society  of  Dyers  and  Colorists.  By  F.  H.  Bow- 
man, D.  Sc,  F.  R.  S.  E.,  F.  L.  S.      Illustrated   by  32   engravings. 

8vo fe.ooi 

BYRNE. — Hand-Book  for  the  Artisan,  Mechanic,  and  Engi- 
neer : 

Comprising  the  Grinding  and  Sharpening  of  Cutting  Tools,  Abia-.ve 
Processes,  Lapidary  Work,  Gem  and  Glass  Engraving,  Varnishing 
and  Lackering,  Apparatus,  Materials  and  Processes  for  Grinding  and 


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Polishing,  etc.  By  Oliver  Byrne.  Illustrated  by  185  wood  en- 
gravings.    8vo. $5»Oc 

8YRNE.— Pocket-Book  for  Railroad  and  Civil  Engineers  : 

Containing  New,  Exact  and  Concise  Methods  for  Laying  out  Railroad 
Curves,  Switches,  Frog  Angles  and  Crossings ;  the  Staking  out  of 
work;  Levelling;  the  Calculation  of  Cuttings;  Embankments;  Earth- 
work, etc.  By  Oliver  Byrne.  i8mo.,  full  bound,  pocket-book 
form  ..........        $1.50 

BYRNE.— The  Practical  Metal-Worker's  Assistant : 
Comprising  Metallurgic  Chemistry;  the  Arts  of  Working  all  Metals 
and  Alloys;  Forging  of  Iron  and  Steel;  Hardening  and  Tempering; 
Melting  and  Mixing;  Casting  and  Founding  ;  Works  in  Sheet  Metal; 
the  Processes  Dependent  on  the  Ductility  of  the  Metals;  Soldering; 
and  the  most  Improved  Processes  and  Tools  employed  by  Metal- 
workers. With  the  Application  of  the  Art  of  Electro-Metallurgy  to 
Manufacturing  Processes ;  collected  from  Original  Sources,  and  from 
the  works  of  Holtzapffel,  Bergeron,  Leupold,  Plumier,  Napier, 
Scoffern,  Clay,  Fairbairn  and  others.  By  Oliver  Byrne.  A  new, 
revised  and  improved  edition,  to  which  is  added  an  Appendix,  con- 
taining The  Manufacture  of  Russian  Sheet- Iron.  By  John  Percy, 
M.  D.,  F.  R.  S.  The  Manufacture  of  Malleable  Iron  Castings,  and 
Improvements  in  Bessemer  Steel.  By  A.  A.  Fesquet,  Chemist- and 
Engineer.  With  over  Six  Hundred  Engravings,  Illustrating  every 
Branch  of  the  Subject.     8vo #5-OC 

BYRNE.— The  Practical  Model  Calculator: 
For  the  Engineer,  Mechanic,  Manufacturer  of  Engine  Work,  Naval 
Architect,  Miner  and  Millwright.     By  Oliver  Byrne.     8vo.,  nearly 
600  pages  .........         &3-00 

CABINET  MAKER'S  ALBUM  OF  FURNITURE'. 
Comprising  a  Collection  of  Designs  for  various  Styles  of  Furniture. 
Illustrated  by  Forty-eight   Large  and   Beautifully  Engraved   Plates. 
Oblong,  8vo .  #1.50 

CALLINGHAM.— Sign  Writing  and  Glass  Embossing: 

A  Complete  Practical  Illustrated  Manual  of  the  Art.  By  James 
Callingham.  To  which  are  added  Numerous  Alphabets  and  the 
Art  of  Letter  Painting  Made  Easy.  By  James  C.  Badenoch.  258 
pages.     i2mo. $1 .50 

CAMPIN. — A  Practical  Treatise  on  Mechanical  Engineering: 
Comprising  Metallurgy,  Moulding,  Casting,  Forging,  Tools,  Work* 
shop  Machinery,  Mechanical  Manipulation,  Manufacture  of  Steam' 
Engines,  etc.  With  an  Appendix  on  the  Analysis  of  Iron  and  Iron 
Ores.  By  Francis  Campin,  C.  E.  To  which  are  added,  Observations 
on  the  Construction  of  Steam  Boilers,  and  Remarks  upon  Furnaces 
used  for  Smoke  Prevention ;  with  a  Chapter  on  Explosions.  Bv  R. 
Armstrong,  C.  E.,  and  John  Bourne.  (Scarce.) 


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CAREY.— A  Memoir  of  Henry  C.  Carey. 
By  Dr.  Wm.  Elder.    With  a  portrait.     8vo.,  cloth         .        .        75 

CAREY.— The  Works  of  Henry  C.  Carey : 

Harmony  of  Interests  :    Agricultural,  Manufacturing  and  Commer- 
cial.    8vo.  .....  .         .         $1.25 

Manual  of  Social  Science.     Condensed  from  Carey's  "  Principles 
of  Social  Science."     By  Kate  McKean.  i  vol.  i2mo.     .        #2.00 
Miscellaneous  Works.     With  a  Portrait.    2  vols.    8vo.         #10.00 
Past,  Present  and  Future.     8vo.    ...         .         .         .         #2.50 

Principles  of  Social  Science.  3  volumes,  8vo.  .  .  $7.50 
The  Slave-Trade,  Domestic  and  Foreign;  Why  it  Exists,  and 
How  it  may  be  Extinguished  (1853).     8vo.        .         .  ,         #2.00 

The  Unity  of  Law :  As  Exhibited  in  the  Relations  of  Physical, 
Social,  Mental  and  Moral  Science  (1872).     8vo.         .         .         #2.50 

CLARK. — Tramways,  their  Construction  and  Working : 

Embracing  a  Comprehensive  History  of  the  System.  With  an  ex' 
haustive  analysis  of  the  various  modes  of  traction,  including  horse- 
power, steam,  heated  water  and  compressed  air;  a  description  of  the 
varieties  of  Rolling  stock,  and  ample  details  of  cost  and  working  ex- 
penses. By  D.  Kinnear  Clark.  Illustrated  by  over  200  wood 
engravings,  and  thirteen  folding  plates.       I  vol.     8vo.         .        #7.50 

COLBURN.— The  Locomotive  Engine  : 

Including  a  Description  of  its  Structure,  Rules  for  Estimating  its 
Capabilities,  and  Practical  Observations  on  its  Construction  and  Man- 
agement.    By  Zerah  Colburn.    Illustrated.     121110.         .         #1.00 

ELLENS.— The  Eden  of  Labor;  or,  the  Christian  Utopia. 
By  T.  Wharton  Collens,  author  of  "  Humanics,"    "  The  Historj 
of  Charity,"  etc.     i2mo.     Paper  cover,  #1.00;  Cloth  .         #1.25 

^OOLEY. — A  Complete  Practical  Treatise  on  Perfumery : 
Being  a  Hand-book  of  Perfumes,  Cosmetics  and  other  Toilet  Articlet 
With   a  Comprehensive    Collection  of  Formulae.     By   Arnold  } 
Cooley.    121110 #i.fjo 

COOPER.- A  Treatise  on  the  use  of  Belting  for  the  Trant- 
mission  of  Power. 
With  numerous  illustrations  of  approved  and  actual  methods  of  ar 
ranging  Main  Driving  and  Quarter  Twist  Belts,  and  of  Belt  Fasten 
ings.  Examples  and  Rules  in  great  number  for  exhibiting  and  cal- 
culating the  size  and  driving  power  of  Belts.  Plain,  Particular  and 
Practical  Directions  for  the  Treatment,  Care  and  Management  or 
Belts.  Descriptions  of  many  varieties  of  Beltings,  together  witn 
chapters  on  the  Transmission  of  Power  by  Ropes;  by  Iron  and 
Wood  Frictional  Gearing;  on  the  Strength  of  Belting  Leather;  and 
on  the  Experimental  Investigations  of  Morin,  Briggs,  and  others.  By 
John  H.  CoorER,  M.  E.  8vo #3-50 

CRAIK. — The  Practical  American  Millwright  and  MUler. 
By  David  Craik,  Millwright.     Illustrated  by  numerous  wood  en 
gcavings  and  two  folding  plates.     $vo (Scarce.) 


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CROSS.— The  Cotton  Yarn  Spinner: 

Showing  how  the  Preparation  should  be  arranged  for  Differem. 
Counts  of  Yarns  by  a  System  more  uniform  than  has  hitherto  been 
practiced;  by  having  a  Standard  Schedule  from  which  we  make  all 
our  Changes.     By  Richard  Cross.     122  pp.     i2mo.         .  75 

CRISTIANI.— A  Technical  Treatise  on  Soap  and  Candles: 
With  a  Glance  at  the  Industry  of  Fats  and  Oils.     By  R.  S.  Cris- 
tiani,  Chemist.     Author  of  "  Perfumery  and  Kindred  Arts."     Illus- 
trated by  176  engravings.     581  pages,  8vo.  $15.00 

COURTNEY.— The    Boiler    Maker's  Assistant   in   Drawing, 
Templating,   and    Calculating    Boiler   Work    and    Tank 
Work,  etc. 
Revised  by  D.  K.  Clark.     102  ills.     Fifth  edition.     .        .        80 
COURTNEY.— The  Boiler  Maker's  Ready  Reckoner: 

With  Examples  of  Practical  Geometry  and  Templating.  Revised  by 
D.  K.  CLARK,  C.  E.     37  illustrations.     Fifth  edition.        •         $1.60 

DAVIDSON.— A  Practical  Manual  of  House  Painting,  Grain- 
ing, Marbling,  and  Sign- Writing: 
Containing  full  information  on  the  processes  of  House  Painting  in 
Oil  and  Distemper,  the  Formation  of  Letters  and  Practice  of  Sign- 
Writing,  the  Principles  of  Decorative  Art,  a  Course  of  Elementary 
Drawing  for  House  Painters,  Writers,  etc.,  and  a  Collection  of  Useful 
Receipts.  With  nine  colored  illustrations  of  Woods  and  Marbles, 
and  numerous  wood  engravings.     By  Ellis  A,  Davidson.     i2mo. 

$2.00 

DAVIES.— A  Treatise  on  Earthy  and  Other    Minerals   and 
Mining: 
By  D.  C.  Davies,  F.  G.  S.,  Mining  Engineer,  etc.     Illustrated  by 
76  Engravings.     l2mo.         .......     $5.00 

DAVIES. — A  Treatise  on  Metalliferous  Minerals  and  Mining: 
By  D.  C.  Davies,  F.  G.  S  ,  Mining  Engineer,  Examiner  of  Mines, 
Quarries  and  Collieries.  Illustrated  by  148  engravings  of  Geological 
Formations,  Mining  Operations  and  Machinery,  drawn  from  the 
practice  of  all  parts  of  the  world.  Fifth  Edition,  thoroughly  Revised 
and  much  Enlarged  by  his  son,  E.  Henry  Davies.  i2mo.,  524 
pages        .......  .  #5-oo 

DAVIES.— A  Treatise  on  Slate  and  Slate  Quarrying: 

Scientific,  Practical  and  Commercial.  By  D  C.  Davies,  F.  G.  S., 
Mining  Engineer,  etc.  With  numerous  illustrations  and  folding 
plates.     !2mo. $1.20 

DAVIS. — A  Practical  Treatise  on  the  Manufacture  of  Brick, 

Tiles  and  Terra-Cotta  : 

Including  Stiff  Clay,  Dry  Clay,  Hand   Made,  Pressed  or  Front,  and 

Roadway  Paving  Brick,  Enamelled  Brick,  with  Glazes  and  Colors, 

Fire  Brick  and  Blocks,  Silica  Brick,  Carbon  Brick,  Glass  Pots,  Re- 


lo  HENRY  CAREY  BAIRD  &  CO.'S  CATALOGS.* 

torts,  Architectural  Terra-Cotta,  Sewer  Pipe,  Drain  Tile,  Glazed  and 
Unglazed  Roofing  Tile,  Art  Tile,  Mosaics,  and  Imitation  of  Intarsia 
or  Inlaid  Surfaces.  Comprising  every  product  of  Clay  employed  in 
Architecture,  Engineering,  and  the  Blast  Furnace.  With  a  Detailed 
Description  of  the  Different  Clays  employed,  the  Most  Modern 
Machinery,  Tools,  and  Kilns  used,  and  the  Processes  for  Handling, 
Disintegrating,  Tempering,  and  Moulding  the  Clay  into  Shape,  Dry- 
ing, Setting,  and  Burning.  By  Charles  Thomas  Davis.  Third  Edi- 
tion. Revised  and  in  great  part  rewritten.  Illustrated  by  261 
engravings.     662  pages     .         .         .         .         .  •       .         .         $5 .00 

DAVIS. — A  Treatise  on  Steam-Boiler  Incrustation  and  Meth- 
ods for  Preventing  Corrosion  and  the  Formation  of  Scale: 
By  Charles  T.  Davis.     Illustrated  by  65  engravings.     8vo. 

DAVIS.— The  Manufacture  of  Paper: 

Being  a  Description  of  the  various  Processes  for  the  Fabrication, 
Coloring  and  Finishing  of  every  kind  of  Paper,  Including  the  Dif- 
ferent Raw  Materials  and  the  Methods  for  Determining  their  Values, 
the  Tools,  Machines  and  Practical  Details  connected  with  an  intelli- 
gent and  a  profitable  prosecution  of  the  art,  with  special  reference  to 
the  best  American  Practice.  To  which  are  added  a  History  of  Pa- 
per, complete  Lists  of  Paper-Making  Materials,  List  of  American 
Machines,  Tools  and  Processes  used  in  treating  the  Raw  Materials, 
and  in  Making,  Coloring  and  Finishing  Paper.  By  Charles  T. 
Davis.     Illustrated  by  156  engravings.     608  pages,  8vo.  $6.00 

DAVIS.— The  Manufacture  of  Leather: 

Being  a  Description  of  all  the  Processes  for  the  Tanning  and  Tawing 
with  Bark,  Extracts,  Chrome  and  all  Modern  Tannages  in  General 
Use,  and  the  Currying,  Finishing  and  Dyeing  of  Every  Kind  of  Leather ; 
Including  the  Various  Raw  Materials,  the  Tools,  Machines,  and  all 
Details  of  Importance  Connected  with  an  Intelligent  and  Profitable 
Prosecution  of  the  Art,  with  Special  Reference  to  the  Best  American 
Practice.  To  which  are  added  Lists  of  American  Patents  ( 1884-1897) 
for  Materials,  Processes,  Tools  and  Machines  for  Tanning,  Currying, 
etc.  By  Charles  Thomas  Davis.  Second  Edition,  Revised,  and 
in  great  part  Rewritten.  Illustrated  by  147  engravings  and  14  Sam- 
ples of  Quebracho  Tanned  and  Aniline  Dyed  Leathers.  8vo,  cloth, 
712  pages.     Price $7-5° 

DAWIDOWSKY— BRANNT.— A   Practical  Treatise  on  the 

Raw  Materials  and  Fabrication  of  Glue,  Gelatine,  Gelatine 

Veneers  and  Foils,  Isinglass,  Cements,  Pastes,  Mucilages, 

etc. : 

Based  upon  Actual  Experience.     By  F.  Dawidowsky,  Technical 

Chemist.     Translated  from  the   German,  with   extensive  additions, 

including  a  description  of  the  most  Recent  American  Processes,  by 

William  T.  Brannt,  Graduate  of  the  Royal  Agricultural  College 

of  Eldena,  Prussia.     35  Engravings.     i2mo.    .         .         .         #2.50 

DE  GRAFF.— The  Geometrical  Stair-Builders'  Guide: 
Being  a  Plain  Practical  System  of  Hand-Railing,  embracing  all  it9 
necessary  Details,  and  Geometrically  Illustrated  by  twenty-two  Steel 
Engravings ;   together  with  the  use  of  the  most  approved  principle? 
of  Practical  Geometry.      By  Simon  De  Graff,  Architect  (Scarce.) 


HENRY  CAREY   BAIRD   &   CO.'S   CATALOGUE.       H 

DE  KONINCK— DIETZ.— A  Practical  Manual  of  Chemical 
Analysis  and  Assaying : 

As  applied  to  the  Manufacture  of  Iron  from  its  Ores,  and  to  Cast  Iron, 
Wrought  Iron,  and  Steel,  as  found  in  Commerce.  By  L.  L.  De 
Koninck,  Dr.  Sc,  and  E.  Dietz,  Engineer.  Edited  with  Notes,  by 
Robert  Mallet,  F.  R.  S.,  F.  S.  G.,  M.  I.  C.  E.,  etc.  American 
Edition,  Edited  with  Notes  and  an  Appendix  on  Iron  Ores,  by  A.  A. 
Fesquet,  Chemist  and  Engineer.     i2mo.  .         .         .         $1.50 

DUNCAN.— Practical  Surveyor's  Guide: 
Containing  the  necessary  information  to  make  any  person  of  com 
mon  capacity,  a  finished  land  surveyor  without  the  aid  of  a  teacher 
By  Andrew  Duncan.    Revised.  72  engravings,  2,14  pp.  i2mo.  $1.50 

CUPLAIS. — A  Treatise  on  the  Manufacture  and  Distillation 
of  Alcoholic  Liquors : 
Comprising  Accurate  and  Complete  Details  in  Regard  to  Alcohol 
from  Wine,  Molasses,  Beets,  Grain,  Rice,  Potatoes,  Sorghum,  Aspho 
del,  Fruits,  etc. ;  with  the  Distillation  and  Rectification  of  Brandy 
Whiskey,  Rum,  Gin,  Swiss  Absinthe,  etc.,  the  Preparation  of  Aro- 
matic Waters,  Volatile  Oils  or  Essences,  Sugars,  Syrups,  Aromatic 
Tinctures,  Liqueurs,  Cordial  Wines,  Effervescing  Wines,  etc.,  the 
Ageing  of  Brandy  and  the  improvement  of  Spirits,  with  Copious 
Directions  and  Tables  for  Testing  and  Reducing  Spirituous  Liquors, 
etc*  etc.  Translated  and  Edited  from  the  French  of  MM.  Duplais, 
By  M.  McKennie,  M.  D.     Illustrated.     743  pp.     8vo.         $15.00 

DYER  AND  COLOR-MAKER'S  COMPANION: 

Containing  upwards  of  two  hundred  Receipts  for  making  Colors,  on 
the  most  approved  principles,  for  all  the  various  styles  and  fabrics  now 
in  evistence ;  with  the  Scouring  Process,  and  plain  Directions  for 
Preparing,  Washing-off,  and  Finishing  the  Goods.      i2mo.         $1  OO 

EIDHERR.— The  Techno-Chemical  Guide  to  Distillation: 
A  Hand-Book  for  the  Manufacture  of  Alcohol  and  Alcoholic  Liquors, 
including  the  Preparation  of  Malt  and  Compressed  Yeast.     Edited 
from  the  German  of  Ed.  Eidherr.    Fully  illustrated.    (In  preparation.) 

EDWARDS.— A  Catechism  of  the  Marine  Steam-Engine, 
For  the  use  of  Engineers,  Firemen,  and  Mechanics.  A  Practical 
Work  for  Practical  Men.  By  Emory  Edwards,  Mechanical  Engi- 
neer. Illustrated  by  sixty-three  Engravings,  including  examples  of 
the  most  modern  Engines.  Third  edition,  thoroughly  revised,  with 
much  additional  matter.     1 2  mo.  414  pages        ...         #2  00 

EDWARDS. — Modern  American  Locomotive  Engines, 
Their  Design,  Construction  and  Management.     By  EMORY  EDWARDS* 
Illustrated  i2mo #2.00 

EDWARDS.— The  American  Steam  Engineer: 

Theoretical  and  Practical,  with  examples  of  the  latest  and  most  ap- 
proved American  practice  in  the  design  and  construction  of  Steam 
Engines  and  Boilers.  For  the  use  of  engineers,  machinists,  boiler- 
uvikers,  and  engineering  students.  By  Emory  Edwards.  Fully 
mustrated,  419  pages.     i2mo.  •  $2jjo 


12  HENRY  CAREY  BAIRD  &  CO.'S   CATALOGUE. 


EDWARDS. — Modern  American  Marine  Engines,  Boilers,  and 
Screw  Propellers, 

Their  Design  and   Construction.     Showing  the  Present  Practice  of 
the  most   Eminent  Engineers  and   Marine  Engine  Builders  in  the 
United  States.    Illustrated  by  30  large  and  elaborate  plates.  4to.  $5.00 
EDWARDS.— The  Practical  Steam  Engineer's  Guide 

In  the  Design,  Construction,  and  Management  of  American  Stationary, 
Portable,  and  Steam  Fire- Engines,  Steam  Pumps,  Boilers,  Injectors, 
Governors,  Indicators,  Pistons  and  Rings,  Safety  Valves  and  Steam 
Gauges.  For  the  use  of  Engineers,  Firemen,  and  Steam  Users.  By 
Emory  Edwards.  Illustrated  by  119  engravings.  420  pages. 
i2mo #2  50 

EISSLER.— The  Metallurgy  of  Gold  : 
A  Practical  Treatise  on  the  Metallurgical  Treatment  of  Gold-Bear- 
ing  Ores,  including  the  Processes  of  Concentration  and  Chlorination, 
and  the  Assaying,  Melting,  and  Refining  of  Gold.     By  M.  Eissler. 

With  132  Illustrations.     i2mo #7«50 

EISSLER.— The  Metallurgy  of  Silver  : 

A  Practical  Treatise  on  the  Amalgamation,  Roasting,  and  Lixiviation 
of  Silver  Ores,  including   the  Assaying,   Melting,  and  Refining  of 
Silver    Bullion.     By    M.     Eissler.     124    Illustrations.      336    pp. 
i2mo.       ..........         $4.25 

ELDER. — Conversations  on  the  Principal  Subjects  of  Political 
Economy. 

By  Dr.  William  Elder.     8vo #2.50 

ELDER.— Questions  of  the  Day, 

Economic  and  Social.     By  Dr.  William  Elder.     8vo.     .      $3.00 
ERNI  AND  BROWN.— Mineralogy  Simplified. 

Easy  Methods  of  Identifying  Minerals,  including  Ores,  by  Means  of 
the  Blow-pipe,  by  Flame  Reactions,  by  Humid  Chemical  Analysis, 
and  by  Physical  Tests.     By  Henri  Erni,  A.  M.,  M.  D.     Third  Edi- 
tion, revised,  re-arranged  and  with  the  addition  of  entirely  new  matter, 
including  Tables  for  the  Determination  of  Minerals  by  Chemical  and 
Pyrognostic   Characters,  and  by  Physical  Characters.     By  Amos  P. 
Brown,  E.  M.,  Ph.  D.     350  pp.,  illustrated  by  96  engravings,  pocket- 
book  form,  full  flexible  morocco,  gilt  edges        .         .         .         #2.50 
FAIRBAIRN.— The  Principles  of  Mechanism  and  Machinery 
of  Transmission  • 
Comprising   the    Principles  of   Mechanism,   Wheels,    and    Pulleys, 
Strength  and  Proportions  of  Shafts,  Coupling  of  Shafts,  and  Engag- 
ing and  Disengaging   Gear.     By  Sir  William   Fairbairn,  Bart 
C.   E.     Beautifully   illustrated   by   over   150   wood-cuts.      In  one 

volume.  i2mo ."         .        $2.00 

FLEMING.— Narrow  Gauge  Railways  in  America. 
A  Sketch  of  their  Rise,  Progress,  and  Success.     Valuable  Statistics 
as  to  Grades,  Curves,  Weight  of  Rail,  Locomotives,  Cars,  etc.     By 

Howard  Fleming.     Illustrated,  8vo |i  00 

FORSYTH.— Book  of  Designs  for  Headstones,   Mural,  and 
other  Monuments : 
Containing  78  Designs.     By  James  Forsyth.   With  an  Introduction 
by  Charles  Boutell,  M.  A. .  4  to.,  cloth    -a-,     •        •        #3.50 


HENRY   CAREY   BAIRD   &   CO.'S   CATALOGUE.        13 


FRANKEL— HUTTER.— A  Practical  Treatise  on  the  Manu* 
facture  of  Starch,  Glucose,  Starch-Sugar,  and  Dextrine: 
Based  on  the  German  of  Ladislaus  Von  Wagner,  Professor  in  the 
Royal  Technical  High  School,  Buda-Pest,  Hungary,  and  other 
authorities.  By  Julius  Frankel,  Graduate  of  the  Polytechnic 
School  of  Hanover.  Edited  by  Robert  Hutter,  Chemist,  Practical 
Manufacturer  of  Starch- Sugar.  Illustrated  by  58  engravings,  cover- 
ing every  branch  of  the  subject,  including  examples  of  the  most 
Recent  and  Best  American  Machinery.     8vo.,  344  Dp.      .         $3.  co 

GARDNER.— The  Painter's  Encyclopaedia: 
Containing  Definitions  of  all  Important  Words  in  the  Art  of  Plain 
and  Artistic  Painting,  with  Details  of  Practice  in  Coach,  Carriage, 
Railway  Car,  House,  Sign,  and  Ornamental  Painting,  including 
Graining,  Marbling,  Staining,  Varnishing,  Polishing,  Lettering, 
Stenciling,  Gilding,  Bronzing,  etc.  By  Franklin  B.  Gardner. 
158  Illustrations.     l2mo.     427  pp $2.oc 

GARDNER.— Everybody's  Paint  Book  : 

A  Complete  Guide  to  the  Art  of  Outdoor  and  Indoor  Painting.  38 
illustrations.      !2mo,  183  pp ,  #1.00 

GEE. — The  Jeweller's    Assistant  in  the   Art  of  Working  in 
Gold: 
A  Practical  Treatise  for  Masters  and  Workmen.     i2mo.      .       $3.00 
GEE.— The  Goldsmith's  Handbook : 

Containing  full  instructions  for  the  Alloying  and  Working  of  Gold, 
including  the  Art  of  Alloying,  Melting,  Reducing,  Coloring,  Col- 
lecting, and  Refining;  the  Processes  of  Manipulation,  Recovery  of 
Waste;  Chemical  and  Physical  Properties  of  Gold;  with  a  New 
System  of  Mixing  its  Alloys ;  Solders,  Enamels,  and  other  Useful 
Rules  and  Recipes.     By  George  E.  Gee.     i2mo.   „         .         $1.25 

GEE.— The  Silversmith's  Handbook  : 

Containing  full  instructions  for  the  Alloying  and  Working  of  Silver, 
including  the  different  modes  of  Refininrr  and  Melting  the  Metal;  its 
Solders ;  the  Preparation  of  Imitation  Alloys ;  Methods  of  Manipula- 
tion; Prevention  of  Waste  ;  Instructions  for  Improving  and  Finishing 
the  Surface  of  the  Work ;  together  with  other  Useful  Information  and 
Memoranda.     By  George  E.  Gee.     Illustrated.     i2mo.         Si. 25 

GOTHIC  ALBUM  FOR  CABINET-MAKERS: 

Designs  for  Gothic  Furniture.     Twenty-three  plates.     Oblong  $1.50 

GRANT.  —A  Handbook  on  the  Teeth  of  Gears  : 
Their  Curves,  Properties,  and  Practical  Construction.     By  George 
B.  Grant.     Illustrated.     Third  Edition,  enlarged.     8vo.  #1.00 

GREENWOOD.— Steel  and  Iron  : 

Comprising  the  Practice  and  Theory  of  the  Several  Methods  Pur- 
sued in  their  Manufacture,  and  of  their  Treatment  in  the  Rolling- 
Mills,  the  Forge,  and  the  Foundry.  By  William  Henry  Green* 
WOOD,  F.  C.  S.     With  97  Diagrams,  536  pages.     i2mo.         #1.75 


14       HENRY   CAREY   BAIRD   &   CO.'S  CATALOGUE 


GREGORY. — Mathematics  for  Practical  Men : 

Adapted  to  the  Pursuits  of  Surveyors,  Architects,  Mechanics,  and 
Civil  Engineers.     By  Olinthus  Gregory.     8vo.,  plates        #3.00 

GRISWOLD. — Railroad  Engineer's  Pocket  Companion  for  tht 
Field : 
Comprising  Rules  for  Calculating  Deflection  Distances  and  Angles, 
Tangential  Distances  and  Angles,  and  all  Necessary  Tables  for  En 
gineers;  also  the  Art  of  Levelling  from  Preliminary  Survey  to  the 
Construction  of  Railroads,  intended  Expressly  for  the  Young  En- 
gineer, together  with  Numerous  Valuable  Rules  and  Examples.  By 
W.  Griswold.     i2mo„  tucks $1.50 

'GRUNER. — Studies  of  Blast  Furnace  Phenomena: 

By  M.  L.  Gruner,  President  of  the  General  Council  of  Mines  0$ 
France,  and  lately  Professor  of  Metallurgy  at  the  Ecole  des  Mines. 
Translated,  with  the  author's  sanction,  with  an  Appendix,  by  L.  D, 
B.  Gordon,  F.  R.  S.  E.,  F.  G.  S.     8vo.  .        .        .        #2.50 

Hand-Book  of  Useful  Tables  for  the  Lumberman,  Farmer  and 
Mechanic : 
Containing  Accurate  Tables  of  Logs  Reduced  to  Inch  Board  Meas- 
ure,  Plank,  Scantling  and  Timber  Measure;  Wages  and  Rent,  by 
Week  or  Month;  Capacity  of  Granaries,  Bins  and  Cisterns;  Land 
Measure,  Interest  Tables,  with  Directions  for  Finding  the  Interest  on 
any  sum  at  4,  5,  6,  7  and  8  per  cent.,  and  many  other  Useful  Tables. 
32  mo.,  boards.     186  pages .25 

HASERICK.— The  Secrets  of  the  Art  of  Dyeing  Wool,  Cotton* 
and  Linen, 
Including  Bleaching  and  Coloring  Wool  and  Cotton  Hosiery  and 
Random  Yarns.  A  Treatise  based  on  Economy  and  Practice.  By 
E.  C.  Haserick.  Illustrated  by  323  Dyed  Patterns  of  the  Yarm 
or  Fabrics.    8vo $S-00 

HATS  AND  FELTING: 

A  Practical  Treatise  on  their  Manufacture.  By  a  Practical  Hatter, 
Illustrated  by  Drawings  of  Machinery,  etc.     8vo.       .         .         #1.25 

HERMANN. — Painting  oh  Glass  and  Porcelain,  and  Enamel 
Painting: 
A  Complete  Introduction  to  the  Preparation  of  all  the  Colors  and 
Fluxes  Used  for  Painting  on  Glass,  Porcelain,  Enamel,  Faience  and 
Stoneware,  the  Color  Pastes  and  Colored  Glasses,  together  with  a 
Minute  Description  ot  the  Firing  ot  Colors  and  Enamels,  on  the 
Basis  of  Personal  Practical  Experience  of  the  Art  up  to  Date.  18 
illustrations.     Second  edition. 

HAUPT.— Street  Railway  Motors: 

With  Descriptions  and  Cost  of  Plants  and  Operation  of  the  Various 
Systems  now  in  Use.     I2W9,  «         .         •         .         JM-75 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.         15 

HAUPT. — A  Manual  of  Engineering  Specifications  and  Con- 
tracts. 

By  Lewis  M.  Haupt,  C.  E.  Illustrated  with  numerous  maps. 
328pp.     8vo ^3  00 

HAUPT.— The  Topographer,  His  Instruments  and  Methods. 
By  Lewis  M.  Haupt,  A.  M.,  C.  E.  Illustrated  with  numerous 
plates,  maps  and  engravings.     247  pp.    8vo.      .         .         .         #3.00 

HUGHES. — American  Miller  and  Millwright's  Assistant: 
By  William  Carter  Hughes.    i2mo $1.50 

HULME. — Worked  Examination  Questions  in  Plane  Geomet- 
rical Drawing  : 
For  the  Use  of  Candidates  for  the  Royal  Military  Academy,  Wool- 
wich ;  the  Royal  Military  College,  Sandhurst ;  the  Indian  Civil  En, 
gineering  College,  Cooper's  Hill  ;  Indian  Public  Works  and  Tele- 
graph Departments ;  Royal  Marine  Light  Infantry ;  the  Oxford  and 
Cambridge  Local  Examinations,  etc.  By  F.  Edward  Hulme,  F.  L. 
S.,  F.  S.  A.,  Art-Master  Marlborough  College.  Illustrated  by  300 
examples.     Small  quarto $1.50 

JERVIS.— Railroad  Property: 

A  Treatise  on  the  Construction  and  Management  of  Railways; 
designed  to  afford  useful  knowledge,  in  the  popular  style,  to  the 
holders  of  this  class  of  property ;  as  well  as  Railway  Managers,  Offi- 
cers, and  Agents.  By  John  B.  Jervis,  late  Civil  Engineer  of  the 
Hudson  River  Railroad,  Croton  Aqueduct,  etc.    i2mo.,  cloth       $2.oc 

KEENE.— A  Hand-Book  of  Practical  Gauging: 

For  the  Use  of  Beginners,  to  which  is  added  a  Chapter  on  Distilla- 
tion, describing  the  process  in  operation  at  the  Custom-House  for 
ascertaining  the  Strength  of  Wines.  By  James  B.  Keene,  of  H.  M. 
Customs.     8vo $l.oa 

KELLEY.— Speeches,  Addresses,  and  Letters  on  Industrial  and 
Financial  Questions : 
By  Hon.  William  D.  Kelley,  M.  C.     544  pages,  8vo.  .        $2.50 

KELLOGG.— A  New  Monetary  System  : 
The  only  means  of  Securing  the  respective  Rights  of  Labor  and 
Property,  and  of  Protecting  the  Public  from   Financial  Revulsions. 
By   Edward   Kellogg.     121110.     Paper  cover,  #1.00.     Bound  in 
cloth $1-25 

KEMLO.— Watch- Repairer's  Hand-Book : 
Being  a  Complete  Guide  to  the  Young  Beginner,  in  Taking  Apart, 
Putting  Together,  and  Thoroughly  Cleaning  the  English  Lever  and 
other  Foreign  Watches,  and  all  American  Watches.     By  F.  Kemlo, 
■Hractical  Watchmaker.     With  Illustrations.     i2mo,  .        #1.25 


f6  HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


KENTISH.— A  Treatise  on  a  Box  of  Instruments, 
And  the  Slide  Rule ;  with  the  Theory  of  Trigonometry  and  Loga 
rithms,  including  Practical  Geometry,  Surveying,  Measuring  of  Tim. 
ber,  Cask  and  Malt  Gauging,  Heights,  and  Distances.     By  THOMA? 
Kentish.     In  one  volume.     i2mo.  ....         #i.oa 

KERL—  The  Assayer's  Manual: 

An  Abridged  Treatise  on  the  Docimastic  Examination  of  Ores,  and 
Furnace  and  other  Artificial  Products.  By  Bruno  Kerl,  Professor 
in  the  Royal  School  of  Mines.  Translated  from  the  German  by 
William  T.  Brannt.  Second  American  edition,  edited  with  Ex- 
tensive Additions  by  F.  Lynwood  Garrison,  Men>ber  of  the 
American  Institute  of  Mining  Engineers,  etc.  Illustrated  by  87  en- 
gravings.    8vo.  (Scarce.^) 

KICK.— Flour  Manufacture . 
A  Treatise  on  Milling  Science  and  Practice.  By  Frederick  Kick 
Imperial  Regierungsrath,  Professor  of  Mechanical  Technology  in  tht 
Imperial  German  Polytechnic  Institute,  Prague.  Translated  from 
the  second  enlarged  and  revised  edition  with  supplement  by  H.  H. 
P.  Powles,  Assoc.  Memb.  Institution  of  Civil  Engineers.  Illustrated 
with  28  Plates,  and  167  Wood-cuts.     367  pages.     8vo.      .      #10.00 

KINGZETT.— The  History,  Products,  and  Processes  of  the 
Alkali  Trade : 
Including  the  most  Recent  Improvements.     By  Charles  Thomas 
K 1  nozett.  Consulting  Chemist.    With  23  illustrations.    8vo.       #2.50 

KIRK.— The  Cupola  Furnace : 

A  Practical  Treatise  on  the  Construction  and  Management  of  Foundry 
Cupolas.  By  Edward  Kirk,  Practical  Moulder  and  Melter,  Con- 
sulting Expert  in  Melting.  Illustrated  by  78  engravings.  Second 
Edition,  revised  and  enlarged.     450  pages.     8vo.     1903.  $3-S° 

LANDRIN.— A  Treatise  on  Steel : 

Comprising  its  Theory,  Metallurgy,  Properties,  Practical  Working, 
and  Use.  By  M.  H.  C.  Landrin,  Jr.  From  the  French,  by  A.  A. 
Fesquet.     i2mo $2.50 

LANGBEIN.— A  Complete  Treatise  on  the  Electro-Deposi. 
tion  of  Metals : 
Comprising  Electro-Plating  and  Galvanoplastic  Operations,  the  De- 
position of  Metals  by  the  Contact  and  Immersion  Processes,  the  Color- 
ing of  Metals,  the  Methods  of  Grinding  and  Polishing,  as  well  as 
Descriptions  of  the  Electric  Elements,  Dynamo-Electric  Machines, 
Thevmo-Piles  and  of  the  Materials  and  Processes  used  in  Every  De- 
partment of  the  Art.  From  the  German  of  Dr.  George  Langbein, 
with  additions  by  Wm.  T.  Brannt.  Fourth  Edition,  thoroughly  revised 
and  much  enlarged.    150  Engravings.   590  pages.   8vo.    1902.     $4.00 

LARDNER.— The  Steam-Engine : 
For  the  Use  of  Beginners.     Illustrated.     i2mo.    •         •        •       .60 

LEHNER.— The  Manufacture  of  Ink: 
Comprising  the  Raw  Materials,  and  the  Preparation  df  W«iting, 
Copying  and  Hektograph  Inks,  Safety  Inks,  Ink  Extracts  and  Pow- 
ders, etc.     Translated  from  the  German  of  SiGMUND  Lehner,  with 
additions  by  William  T.  Brannt.    Illustrated.     i2mo.  $zJoo 


HENRY   CAREY    BAIRD   &   GO.'S   CATALOGUE.        17 

LARKIN* — The  Practical  Brass  and  Iron  Founder's  Guide  1 
A  Concise  Treatise  on  Brass  Founding,  Moulding,  the  Metals  and 
their  Alloys,  etc. ;  to  which  are  added  Recent  Improvements  in  the 
Manufacture  of  Iron,  Steel  by  the  Bessemer  Process,  etc.,  etc.  Bj 
Tames  Larkin,  late  Conductor  of  the  Brass  Foundry  Department  ia 
Keany,  Neafie  &  Co.'s  Penn  Works,  Philadelphia.  New  edition, 
revised,  with  extensive  additions.    414  pages.     121x10.         .         $2.50 

LEROUX.— A  Practical  Treatise  on  the  Manufacture  0$ 
Worsteds  and  Carded  Yarns  : 
Comprising  Practical  Mechanics,  with  Rules  and  Calculations  applied 
to  Spinning ;  Sorting,  Cleaning,  and  Scouring  Wools ;  the  English 
and  French  Methods  of  Combing,  Drawing,  and  Spinning  Worsteds, 
and  Manufacturing  Carded  Yarns.  Translated  from  the  French  of 
Charles  Leroux,  Mechanical  Engineer  and  Superintendent  of  a 
9pinning-Mill,  by  Horatio  Paine,  M.  D.,  and  A.  A.  Fesquet, 
Chemist  and  Engineer.  Illustrated  by  twelve  large  Plates.  To  which 
is  added  an  Appendix,  containing  Extracts  from  the  Reports  of  the 
International  Jury,  and  of  the  Artisans  selected  by  the  Committe* 
appointed  by  the  Council  of  the  Society  of  Arts,  London,  on  Woolec 
and  Worsted  Machinery  and  Fabrics,  as  exhibited  in  the  Paris  Uni« 
versal  Exposition,  1867.    8vo.  .....         $5.00 

LEFFEL. — The  Construction  of  Mill-Dams  : 
Comprising  also  the  Building  of  Race  and  Reservoir  Embankments 
and  Head-Gates,  the   Measurement  of  Streams,  Gauging  of  Water 
Supply,  etc.     By  James  Leffel  &  Co.    Illustrated  by  58  engravings. 
8vo. $2.50 

LESLIE.— Complete  Cookery: 
Directions  for  Cookery  in  its  Various  Branches.     By  Miss  Leslie. 
Sixtieth  thousand.     Thoroughly  revised,  with  the  addition  of  New 
Receipts.      121110.      .  .         #1-5° 

LE  VAN.— The  Steam  Engine  and  the  Indicator : 

Their  Origin  and  Progressive  Development ;  including  the  Most 
Recent  Examples  of  Steam  and  Gas  Motors,  together  with  the  Indi- 
cator, its  Principles,  its  Utility,  and  its  Application.  By  William 
Barnet  Le  Van.  Illustrated  by  205  Engravings,  chiefly  of  Indi- 
cator-Cards.    469  pp.     8vo $4.00 

LIEBER.— Assayer's  Guide  : 
Or,  Practical  Directions  to  Assayers,  Miners,  and  Smelters,  for  the 
Tests  and  Assays,  by  Heat  and  by  Wet  Processes,  for  the  Ores  of  all 
ty     principal  Metals,  of  Gold  and  Silver  Coins  aad  Alloys,  and  of 
Coal,  etc.     By  Oscar  M.  Lieber.      Revised.  283  pp.  i2mo.     $1.50 

Lockwood's  Dictionary  of  Terms  : 

Used  in  the  Practice  of  Mechanical  Engineering,  embracing  those 
Current  in  the  Drawing  Office,  Pattern  Shop,  Foundry,  Fitting,  Turn- 
ing, Smith's  and  Boiler  Shops,  etc.,  etc.,  comprising  upwards  of  Six 
Thousand  Definitions.  Edited  by  a  Foreman  Pattern  Maker,  author 
tj  "  Patterr  Making."     417  pp.     i2mo.  ,         .  .         $$.75 


18         HENRY  CAREY  BArRD  &  CO.'S  CATALOGUE. 

LUKIN.— The  Lathe  and  Its  Uses : 

Or  Instruction  in  the  Art  of  Turning  Wood  and  Metal.  Including 
a  Description  of  the  Most  Modern  Appliances  for  the  Ornamentation 
of  Plane  and  Curved  Surfaces,  an  Entirely  Novel  Form  of  Lathe 
for  Eccentric  and  Rose-Engine  Turning;  A  Lathe  and  Planing 
Machine  Combined;  and  Other  Valuable  Matter  Relating  to  the 
Art.  Illustrated  by  462  engravings.  Seventh  edition.  315  pages. 
8vo #4.25 

MAIN  and  BROWN.— Questions  on  Subjects  Connected  with 
the  Marine  Steam-Engine : 

And  Examination  Papers;  with  Hints  for  their  Solution.  By 
Thomas  J.  Main,  Professor  of  Mathematics,  Royal  ^aval  College, 
and  Thomas  Brown,  Chief  Engineer,  R.  N.    i2mo.,  cloth  .       #1.00 

MAIN  and  BROWN. — The  Indicator  and  Dynamometer: 
With  their  Practical  Applications  to  the  Steam-Engine.     By  THOMAS 
J.  Main,   M.  A.  F.  R.,  Ass't    S.   Professor   Royal   Naval   College, 
Portsmouth,  and  Thomas  Brown,  Assoc.  Inst.  C.  E.,  Chief  Engineer 
R.  N.,  attached  to  the  R.  N.  College.     Illustrated.     8vo.  . 

MAIN  and  BROWN.— The  Marine  Steam-Engine. 
By  Thomas  J.  Main,  F.  R.  Ass't  S.  Mathematical  Professor  at  the 
Royal    Naval    College,   Portsmouth,  and    Thomas    Brown,  Assoc. 
Inst.  C.  E.,  Chief  Engineer  R.  N.     Attached  to  the  Royal  Naval 
College.     With  numerous  illustrations.     8vo. 

MAKINS.— A  Manual  of  Metallurgy: 

By  George  Hogarth  Makins.  100  engravings.  Second  edition 
rewritten  and  much  enlarged.     i2mo..  592  pages 

MARTIN.— Screw-Cutting  Tables,  for  the  Use  of  Mechanic*) 
Engineers  : 
Showing  the  Proper  Arrangement  of  Wheels  for  Cutting  the  Threads 
of  Screws  of  any  Required  Pitch ;  with  a  Table  for  Making  the  Uni- 
versal Gas-Pipe  Thread  and  Taps.  By  W.  A.  Martin,  Engineer. 
8vo -5o 

MICH  ELL — Mine  Drainage: 
Being  a  Complete  and  Practical  Treatise  on  Direct-Acting  Under 
ground  Steam  Pumping  Machinery.  With  a  Description  of  a  largt 
number  of  the  best  known  Engines,  their  General  Utility  and  ihe 
Special  Sphere  of  their  Action,  the  Mode  of  their  Application,  and 
their  Merits  compared  with  other  Pumping  Machinery.  By  Stephen 
Michell.     Illustrated  by  247  engravings.    8vo.,  369  pages.     $12  50 

MOLESWORTH.— Pocket-Book   of    Useful    Formulae    and 
Memoranda  for  Civil  and  Mechanical  Engineers. 
By  Guilford  L.  Molesworth,  Member  of  the  Institution  of  Civil 
Engineers,  Chief  Resident  Engineer  of  the  Ceylon  Railway.     Full- 
bound  in  Pocket-book  form $1.00 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.         t> 

MOORE.— The  Universal  Assistant  and  the  Complete  Ml 
chanic : 

Containing  over  one  million  Industrial  Facts,  Calculations,  Receipt*. 
Processes,  Trades  Secrets,  Rules,  Business  Forms,  Legal  Items,  Etc., 
in  every  occupation,  from  the  Household  to  the  Manufactory.  By 
R.  Moore.     Illustrated  by  500  Engravings.     i2mo.  .         $2.50 

MORRIS. — Easy  Rules  for  the  Measurement  of  Earthworks : 
By  means  of  the  Prismoidal  Formula.  Illustrated  with  Numerouf 
Wood-Cuts,  Problems,  and  Examples,  and  concluded  by  an  Exten 
sive  Table  for  finding  the  Solidity  in  cubic  yards  from  Mean  Areas, 
The  whole  being  adapted  for  convenient  use  by  Engineers,  Surveyors! 
Contractors,  and  others  needing  Correct  Measurements  of  Earthwork 

By  Elwood  Morris,  C.  E.    8vo #1.50 

MAUCHLINE.— The  Mine  Foreman's  Hand-Book 

Of  Practical  and  Theoretical  Information  on  the  Opening,  Venti- 
lating, and  Working  of  Collieries.      Questions  and  Answers  on  Prac- 
tical  and  Theoretical  Coal  Mining.     Designed  to  Assist  Students  and 
Others   in    Passing    Examinations    for    Mine    Foremanships.     By 
Robert  Mauchline,  Ex-Inspector  of  Mines.    A  New,  Revised  and 
Enlarged    Edition.      Illustrated    by    114   engrarings.      8vo.      337 
pages        ..........         #3-75 

NAPIER. — A  System  of  Chemistry  Applied  to  Dyeing. 
By  James  Napier,  F.  C.  S.  A  New  and  Thoroughly  Revised  Edi- 
tion. Completely  brought  up  to  the  present  state  of  the  Science, 
including  the  Chemistry  of  Coal  Tar  Colors,  by  A.  A.  Fesquet, 
Chemist  and  Engineer.  With  an  Appendix  on  Dyeing  and  Ca)ica 
Printing,  as  shown  at  the  Universal  Exposition,  Paris,  1867.  Illus- 
trated. 8vo.  422  pages #3.00 

NEVILLE.— Hydraulic  Tables,  Coefficients,  and  Formulae,  fot 
finding  the  Discharge  of  Water  from  Orifices,  Notches, 
Weirs,  Pipes,  and  Rivers : 
Third  Edition,  with  Additions,  consisting  of  New  Formulae  for  the 
Discharge  from  Tidal  and  Flood  Sluices  and  Siphons ;  general  infor 
mation  on  Rainfall,  Catchment-Basins,  Drainage,  Sewerage,  Water 
Supply  for  Towns  and  Mill  Power.  By  Tohn  Neville,  C.  E.  M  R 
I.  A. ;  Fellow  of  the  Royal  Geological  Society  of  Ireland.     Thick 

l2mo £5.50 

NEWBERY.— Gleanings  from  Ornamental  Art  of  every 
style : 
Drawn  from  Examples  in  the  British,  South  Kensington,  Indian, 
Crystal  Palace,  and  other  Museums,  the  Exhibitions  of  1851  and 
1862,  and  the  best  English  and  Foreign  works.  In  a  series  of  100 
exquisitely  drawn  Plates,  containing  many  hundred  examples.     By 

Robert  Newbery.    4to. (Scarce.) 

NICHOLLS.—  The  Theoretical  and  Practical  Boiler- M aker  and 
Engineer's  Reference  Book: 
Containing  a  variety  of  Useful  Information  for  Employers  of  Labor 
Foremen  a'\d  Working  Boiler-Makers.  Iron,  Copper,  and  Tinsnuth* 


20        HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

Draughtsmen,  Engineers,  the  General  Steam- using  Public,  and  for  the 
Use  of  Science  Schools  and  Classes.  By  Samuel  NiCHOLLS.  Illus* 
trated  by  sixteen  plates,  i2mo. #2.5C 

NICHOLSON.— A  Manual  of  the  Art  of  Bookbinding : 
Containing  full  instructions  in  the  different  Branches  of  Forwarding, 
Gilding,  and  Finishing.     Also,  the  Art  of  Marbling  Book-edges  and 
Paper.     By  James  B.  Nicholson.     Illustrated.  i2mo.,  cloth     #2.25 

NICOLLS.— The  Railway  Builder: 
A  Hand-Book  for  Estimating  the  Probable  Cost  of  American  Rail- 
way Construction  and  Equipment.     By  William  J.  Nicolls,  Civil 
Engineer.    Illustrated,  full  bound,  pocket-book  form  .         $2.00 

NORMANDY.— The  Commercial  Handbook  of  Chemical  An- 
alysis : 
Or  Practical  Instructions  for  the  Determination  of  the  Intrinsic  01 
Commercial  Value  of  Substances  used  in  Manufactures,  in  Trades, 
and  in  the  Arts.  By  A.  Normandy.  New  Edition,  Enlarged,  and 
to  a  great  extent  rewritten.  By  Henry  M.  Noad,  Ph.D.,  F.R.S., 
thick  i2mo Scarce 

NORRIS. — A  Handbook  for  Locomotive  Engineers  and  Ma- 
chinists : 
Comprising  the  Proportions  and  Calculations  for  Constructing  Loco- 
motives; Manner  of  Setting  Valves;  Tables  of  Squares,  Cubes,  Areas, 
etc.,  etc.  By  Septimus  Norris,  M.  E.  New  edition.  Illustrated, 
I2mo. $1.50 

NYSTROM. — A  New  Treatise  on  Elements  of  Mechanics : 
Establishing  Strict  Precision  in  the   Meaning  of  Dynamical  Terms  1 
accompanied  with  an  Appendix  on  Duodenal  Arithmetic  and   Me* 
trology.     By  John  W.  Nystrom,  C.  E.     Illustrated.     8vo.        #3.0* 

NYSTROM. — On  Technological  Education  and  the  Construc- 
tion of  Ships  and  Screw  Propellers : 
For  Naval  and  Marine  Engineers.     By  John  W.  Nystrom,  IaU 
Acting  Chief  Engineer,  U.  S.  N.     Second  edition,  revised,  with  addi 
tional  matter.     Illustrated  by  seven  engravings.      i2mo.     .         $l-2l 

O'NEILL. — A  Dictionary  of  Dyeing  and  Calico  Printing: 
Containing  a  brief  account  of  all  the  Substances  and  Processes  in 
use  in  the  Art  of  Dyeing  and  Printing  Textile  Fabrics  ;  with  Practical 
Receipts  and  Scientific  Information.  By  Charles  O'Neill,  Analy- 
tical Chemist.  To  which  is  added  an  Essay  on  Coal  Tar  Colors  and 
their  application  to  Dyeing  and  Calico  Printing.  By  A.  A.  Fesquet, 
Chemist  and  Engineer.  With  an  appendix  on  Dyeing  and  Calico 
Printing,  as  shown  at  the  Universal  Exposition,  Paris,   1867-     8vo., 

491  pages  . $3.00 

•RTON. — Underground  Treasures-. 

How  and  Where  to  Find  Them.  A  Key  for  the  Ready  Determination 
of  all  the  Useful  Minerals  within  the  United  States.  By  James 
OrTON,  A.M.,  Late  Professor  of  Natural  History  in  Vassar  College, 
N.  Y.;  author  of  the  "Andes  and  the  Amazon,"  etc.  A  New  Edi- 
tion, with  An  Appendix  on  Ore  Deposits  and  Testing  Minerals  (1901). 
Illustrated ,         $1-50 


HENRY    CAREY   BAIRD   &   CO.'S   CATALOGUE.        21 

OSBORN.— The  Prospector's  Field  Book  and  Guide. 

In  the  Search  For  and  the  Easy  Determination  of  Ores  and  Other 
Useful  Minerals.  By  Prof.  H.  S.  Osborn,  LL.  D.  Illustrated  by  58 
Engravings.      i2mo.      Fifth      Edition.      Revised    and    Enlarged 

(iqoi) I1.50 

OSBORN — A  Practical  Manual  of  Minerals,  Mines  and  Min- 
ing: 
Comprising  the  Physical  Properties,  Geologic  Positions,  Local  Occur- 
rence and   Associations  of  the  Useful  Minerals;  their  Methods   of 
Chemical  Analysis  and  Assay  ;  together  with  Various  Systems  of  Ex- 
cavating and  Timbering,  Brick  and  Masonry  Work,  during  Driving, 
Lining,  Bracing  and  other  Operations,  etc.     By  Prof.  H.  S.  Osborn, 
LL.  D.,  Author  of  «  The  Prospector's  Field-Book  and  Guide."     171 
engravings.     Second  Edition,  revised.     8vo.      .         .         .         $4.50 
OVERMAN.— The  Manufacture  of  Steel : 
Containing  the  Practice  and  Principles  of  Working  and  Making  Steel. 
A  Handbook  for  Blacksmiths  and  Workers  in  Steel  and  Iron,  Wagon 
Makers,  Die  Sinkers,  Cutlers,  and  Manufacturers  of  Files  and  Hard- 
ware,  of  Steel  and    Iron,  and  for  Men   of  Science  and  Art.     By 
Frederick  Overman,  Mining  Engineer,  Author  of  the  "  Manu- 
facture of  Iron,"  etc.     A  new,  enlarged,  and  revised  Edition.     By 
A.  A.  Fesql'£T,  Chemist  and  Engineer.     i2mo.         .         .         $1.50 
OVERMAN.— The  Moulder's  and  Founder's  Pocket  Guide  : 
A  Treatise  on  Moulding  and  Founding  in  Green-sand,  Dry-sand,  Loam, 
and  Cement;  the  Moulding  of  Machine  Frames,  Mill-gear,  Hollow* 
ware,  Ornaments,  Trinkets,  Bells,  and  Statues;  Description  of  Moulds 
for  Iron,  Bronze,  Brass,  and  other  Metals;   Plaster  of  Paris,  Sulphur, 
Wax,  etc. ;  the  Construction  of  Melting  Furnaces,  the  Melting  and 
Founding  of  Metals  ;  the  Composition  of  Alloys  and  their  Nature, 
etc.,  etc.     By  Frederick  Overman,  M.  E.     A  new  Edition,  ta 
which  is  added  a  Supplement  on  Statuary  and  Ornamental  Moulding, 
Ordnance,  Malleable  Iron  Castings,  etc.     By  A.  A.  Fesquet,  Chenv- 
ist  and  Engineer.     Illustrated  by  44  engravings.     l2mo.    .         $2.oCI 
PAINTER,  GILDER,  AND  VARNISHER'S  COMPANION. 
Comprising  the  Manufacture  and  Test  of  Pigments,  the  Arts  of  Paint 
ing,  Graining,  Marbling,  Staining,  Sign- writing,  Varnishing,  Glass- 
staining,  and   Gilding  on  Glass ;   together  with  Coach  Painting  and 
Varnishing,   and  the    Principles    of  the  Harmony  and  Contrast  of 
Colors.     Twenty-seventh  Edition.     Revised,  Enlarged,  and  in  great 
part  Rewritten.     By  William  T.  Brannt,  Editor  of  "  Varnishes, 
Lacquers,  Printing  Inks  and  Sealing  Waxes."     Illustrated.     395  pp. 

121110.  , $1 .50 

PALLETT.— The  Miller's,  Millwright's,  and  Engineer's  Guide. 
By  Henry  Pallett.     Illustrated.     i2mo.       .         .         .         #2.00 


22         riENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

PERCY.— The  Manufacture  of  Russian  Sheet-Iron. 
By  John  Percy,  M.  D.,  F.  R.  S.     Paper.      ...        25  cts. 

PERKINS.— Gas  and  Ventilation: 

Practical  Treatise  on  Gas  and  Ventilation.    Illustrated.    I2mo.    $1.25 

PERKINS  AND  STOWE.-A  New  Guide  to  the  Sheet-iron 
and  Boiler  Plate  Roller  : 
Containing  a  Series  of  Tables  showing  the  Weight  of  Slabs  and  Piles 
to  Produce  Boiler  Plates,  and  of  the  Weight  of  Piles  and  the  Sizes  of 
Bars  to  produce  Sheet-iron ;  the  Thickness  of  the  Bar  Gauge 
in  decimals ;  the  Weight  per  foot,  and  the  Thickness  on  the  Bar  or 
Wire  Gauge  of  the  fractional  parts  of  an  inch;  the  Weight  per 
sheet,  and  the  Thickness  on  the  Wire  Gauge  of  Sheet-iron  of  various 
dimensions  to  weigh  112  lbs.  per  bundle;  and  the  conversion  of 
Short  Weight   into    Long   Weight,  and    Long  Weight   into    Short. 

#1.50 

POSSELT. — Recent  Improvements  in  Textile  Machinery  Re- 
lating to  Weaving : 
Giving  the  Most  Modern  Points  on  the  Construction  of  all  Kinds 
of  Looms,  Warpers,  Beamers,  Slashers,  Winders,  Spoolers,  Reeds, 
Temples,  Shuttles,  Bobbins,  Heddles,  Heddle  Frames,  Pickers, 
Jacquards,  Card  Stampers,  etc.,  etc.     600  illus.  .         .         $3  00 

POSSELT.— Technology  of  Textile  Design: 
The  Most  Complete  Treatise  on  the  Construction  and  Application 
of  Weaves  for  all  Textile  Fabrics  and  the  Analysis  of  Cloth.     By  E. 
A.  Posselt.     1,500  illustrations.     4to $5-00 

POSSELT. — Textile  Calculations: 

A  Guide  to  Calculations  Relating  to  the  Manufacture  of  all  Kinds 
of  Yarns  and  Fabrics,  the  Analysis  of  Cloth,  Speed,  Power  and  Belt 
Calculations.     By  E.  A.  POSSELT.     Illustrated.     4to.        .        #2.00 

REGNAULT.— Elements  of  Chemistry: 
By  M.  V.  Regnault.  Translated  from  the  French  by  T.  Forrest 
Betton,  M.  D.,  and  edited,  with  Notes,  by  James  C.  Booth,  Melter 
and  Refiner  U.  S.  Mint,  and  William  L.  Faber,  Metallurgist  and 
Mining  Engineer.  Illustrated  by  nearly  700  wood-engravings.  Com- 
prising nearly  1,500  pages.     In  two  volumes,  8vo.,  cloth    .        $6.00 

RICHARDS.— Aluminium : 

Its  History,  Occurrence,  Properties,  Metallurgy  and  Applications, 
including  its  Alloys.  By  Joseph  W.  Richards,  A.  C,  Chemist  and 
Practical  Metallurgist,  Member  of  the  Deutsche  Chemische  Gesell- 
schaft.     lllusr.     Third  edition,  enlarged  and  revised  (1895)    .    #6.00 

RIFFAULT,  VERGNAUD,  and  TOUSSAINT.— A  Practical 
Treatise  on  the  Manufacture  of  Colors  for  Painting: 
Comprising  the  Origin,  Definition,  and  Classification  of  Colors;  the 
Treatment  of  the  Raw  Materials ;  the  best  Formulae  and  the  Newest 
Processes  for  the  Preparation  of  every  description  of  Pigment,  and 
the  Necessary  Apparatus  and  Directions  for  its  Use;  Dryers;  the 
Testing.  Application,  and  Qualities  of  Paints,  etc.,  etc.  By  MM. 
Riffault,  Vergnaud,  and  Toussaint.     Revised  and  Edited  by  M. 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  *3 


F.  Malepeyre.  Translated  from  the  French,  by  A.  A.  FesQOT^ 
Chemist  and  Engineer.     Illustrated  by  Eighty  engravings.     In  one 

vol.,  8vo.,  659  pages $5-°° 

ROPER. — Catechism  for  Steam  Engineers  and  Electricians: 

Including  the  Construction  and  Management  of  Steam  Engines, 
Steam  Boilers  and  Electric  Plants.  By  Stephen  Roper.  Twenty- 
first  edition,  rewritten  and  greatly  enlarged  by  E.  R.  Keller  and 
C.  W.  Pike.     365  pages.     Illustrations.      i8mo.,  tucks,  gilt.     #2.00 

ROPER.— Engineer's  Handy  Book: 

Containing  Facts,  Formulae,  Tables  and  Questions  on  Power,  its 
Generation,  Transmission  and  Measurement;  Heat,  Fuel,  and  Steam; 
The  Steam  Boiler  and  Accessories;  Steam  Engines  and  their  Parts; 
Steam  Engine  Indicator ;  Gas  and  Gasoline  Engines ;  Materials ; 
their  Properties  and  Strength ;  Together  with  a  Discussion  of  the  Fun- 
damental Experiments  in  Electricity,  and  an  Explanation  of  Dynamos, 
Motors,  Batteries,  etc.,  and  Rules  for  Calculating  Sizes  of  Wires.  By 
Stephen  Roper.  15th  edition.  Revised  and  enlarged  by  E.  R. 
Keller,  M.  E.  and  C.  W.  Pike,  B.  S.  (1899),  with  numerous  illus- 
trations.    Pocket-book  form.     Leather.     ....        $3.50 

ROPER. — Hand-Book  of  Land  and  Marine  Engines  : 
Including  the   Modelling,  Construction,   Running,  and  Management 
of  Land  and  Marine  Engines  and  Boilers.     With  illustrations.     By 
Stephen  Roper,  Engineer.    Sixth  edition.     i2mo.,tvcks,  gilt  edge. 

$3-5* 
ROPER.— Hand-Book  of  the  Locomotive  : 

Including  the  Construction  of  Engines  and  Boilers,  and  the  Construc- 
tion, Management,  and  Running  of  Locomotives.  By  Stephen 
Roper.     Eleventh  edition.     i8mo.,  tucks,  gilt  edge  .         $2. 5a 

ROPER.— Hand-Book  of  Modern  Steam  Fire- Engines. 
With  illustrations.     By  Stephen  Roper,  Engineer.     Fourth  edition, 
i2mo.,  tucks,  gilt  edge #3-50 

ROPER. — Questions  and  Answers  for  Engineers. 

This  little  book  contains  all  the  Questions  that  Engineers  will  be 
asked  when  undergoing  an  Examination  for  the  purpose  of  procuring 
Licenses,  and  they  are  so  plain  that  any  Engineer  or  Fireman  of  or 
dinary  intelligence  may  commit  them  to  memory  in  a  short  time.  By 
Stephen  Roper,  Engineer.     Third  edition       .         .         .         #2.00 

ROPER.— Use  and  Abuse  of  the  Steam  Boiler. 
By  Stephen  Roper,  Engineer.     Eighth  edition,  with  illustrations. 
l8mo.,  tucks,  gilt  edge #2.00 

ROSE.— The  Complete  Practical  Machinist : 

Embracing  Lathe  Work,  Vise  Work,  Drills  and  Drilling,  Taps  and 
Dies,  Hardening  and  Tempering,  the  Making  and  Use  of  Tools 
Tool  Grinding,  Marking  out  Work,  Machine  Tools,  etc.  By  Joshua 
Rose.  395  Engravings.  Nineteenth  Edition,  greatly  Enlarged  with 
New  and  Valuable  Matter.     i2mo.,  504  pages.  .         .         #2.50 

ROSE.— Mechanical  Drawing  Self-Taught : 

Comprising  Instructions  in  the  Selection  and  Preparation  of  Drawing 
Instruments,  Elementary  Instruction  in  Practical  Mechanical  Draw- 


24         HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 

ing,  together  with  Examples  in  Simple  Geometry  and  Elementary 
Mechanism,  including  Screw  Threads,  Gear  Wheels,  Mechanical 
Motions,  Engines  and  Boilers.  By  Joshua  Rose,  M.  E.  Illustrated 
by  330  engravings.     8vo.,  313  pages  ....         #4.00 

ROSE.— The  Slide- Valve  Practically  Explained: 

Embracing  simple  and  complete  Practical  Demonstrations  of  th. 
operation  of  each  element  in  a  Slide-valve  Movement,  and  illustrat- 
ing the  effects  of  Variations  in  their  Proportions  by  examples  care- 
fully  selected  from  the  most  recent  and  successful  practice.  By 
Joshua  Rose,  M.  E.     Illustrated  by  35  engravings  .         $1.00 

ROSS. — The  Blowpipe  in  Chemistry,  Mineralogy  and  Geology: 

Containing  all  Known  Methods  of  Anhydrous  Analysis,  many  Work- 
ing Examples,  and  Instructions  for  Making  Apparatus.  By  Lieut.- 
Colonel  W.  A.   Ross,  R.  A.,  F.  G.  S.      With   120  Illustrations. 

i2mo #2.00 

SHAW.— Civil  Architecture : 

Being  a  Complete  Theoretical  and  Practical  System  of  Building,  con- 
taining  the  Fundamental  Principles  of  the  Art.  By  Edward  Shaw, 
Architect.  To  which  is  added  a  Treatise  on  Gothic  Architecture,  etc. 
By  Thomas  W.  Silloway  and  George  M.  Harding,  Architects. 
The  whole  illustrated  by  102  quarto  plates  finely  engraved  on  copper. 
Eleventh  edition.     4to #6.00 

SHUNK. — A  Practical  Treatise  on  Railway  Curves  and  Loca- 
tion, for  Young  Engineers. 
By  W.  F.  Shunk,  C.  E.     i2mo.    Full  bound  pocket-book  form  $2.00 

SLATER.— The  Manual  of  Colors  and  Dye  Wares. 
By  J.  W.  Slater.     i2mo #3.00 

SLOAN. — American  Houses  : 

A  variety  of  Original  Designs  for  Rural  Buildings.  Illustrated  by 
26  colored  engravings,  with  descriptive  references.  By  Samuel 
Sloan,  Architect.     8vo. .75 

SLOAN. — Homestead  Architecture: 

Containing  Forty  Designs  for  Villas,  Cottages,  and  Farm-houses,  with 
Essays  on  Style,  Construction,  Landscape  Gardening,  Furniture,  etc., 
etc.  JUustrated  by  upwards  of  200  engravings.  By  Samuel  Sloan, 
Architect.     8vo #2.50 

SLOANE.— Hoir»e  Experiments  m  Science. 

By  T.  O'Conor  Slcane,  E.  M.,  A.  M.,  Fh.  D.  Illustrated  by  91 
engravings.     i2mo.  .......        $1.00 

SMEATON.— Builder's  Pocket  Companion : 

4  Containing  the  Elements  of  Building,  Surveying,  and  Architecture; 
with  Practical  Rules  and  Instructions  corrected  with  the  subject. 
By  A.  C.  Smeaton,  Civil  Engineer,  etc.     l2mo. 

SMITH.— A  Manual  of  Political  Economy. 
By  E.  Peshine  Smith.     A  New  Edition,  to  which  is  added  a  full 
Index.     i2mo. #1-25 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  25 

SMITH.— Parks  and  Pleasure-Grounds: 

Or  Practical  Notes  on  Country  Residences,  Villas,  Public  Parks,  and 
Gardens.  By  Charles  H.  J.  Smith,  Landscape  Gardener  and 
Garden  Architect,  etc.,  etc.      121110.  ....         $2.03 

SMITH.— The  Dyer's  Instructor: 

Comprising  Practical  Instructions  in  the  Art  of  Dyeing  Silk,  Cotton* 
Wool,  and  Worsted,  and  Woolen  Goods ;  containing  nearly  800 
Receipts.  To  which  is  added  a  Treatise  on  the  Art  of  Padding;  ancjj 
the  Printing  of  Silk  Warps,  Skeins,  and  Handkerchiefs,  and  tha 
various  Mordants  and  Colors  for  the  different  styles  of  such  work* 
By  David  Smith,  Pattern  Dyer.     121110.  .         .         .        $1.50/ 

SMYTH. — A  Rudimentary  Treatise  on  Coal  and  Coal-Mining. 
By  Warrington  W.  Smyth,  M.  A.,  F.  R.  G.,  President  R.  G.  S, 
of  Cornwall.  Fifth  edition,  revised  and  corrected.  With  numer- 
ous illustrations.      i2mo.  ......         #i«75 

SNIVELY. — Tables  for  Systematic  Qualitative  Chemical  Anal, 
ysis. 
By  John  H.  Snively,  Phr.  D.     8vo.         .         .         .         ,         $i.oa 

SNIVELY. — The  Elements  of  Systematic  Qualitative  chemical 
Analysis : 
A  Hand-book  for  Beginners.    By  John  H.  Snively,  Phr.  D.    i6mo. 

$2.O0 

STOKES.— The  Cabinet-Maker  and  Upholsterer's  Companion: 

Comprising  the  Art  of  Drawing,  as  applicable  to  Cabinet  Work; 
Veneering,  Inlaying,  and  Buhl- Work;  the  Art  of  Dyeing  and  Stain- 
ing Wood,  Ivory,  Bone,  Tortoise-Shell,  etc.  Directions  for  Lacker- 
ing, Japanning,  and  Virnishing;  to  make  French  Polish,  Glues, 
Cements,  and  Compos"".i<"  as ;  with  numerous  Receipts,  useful  to  work 
men  generally.  Bv  Stokes.  Illustrated.  A  New  Edition,  with 
an  Appendix  upor     /ench  Polishing,  Staining,  Imitating,  Varnishing, 

etc.,  etc.    i2mo #1.25 

STRENGTH  AND  OTHER  PROPERTIES  OF  METALS; 
Reports  of  Experiments  on  the  Strength  and  other  Properties  of 
Metals  for  Cannon.  With  a  Description  of  the  Machines  for  Testing 
Metals,  and  of  the  Classification  of  Cannon  in  service.  By  Officers 
of  the  Ordnance  Department,  U.  S.  Army.  By  authority  of  the  Secre- 
tary of  War.  Illustrated  by  25  large  steel  plates.  Quarto  .  $5.00 
SULLIVAN.— Protection  to  Native  Industry. 
By  Sir  Edward  Sullivan,  Baronet,  author  of  "  Ten  Chapters  ©11 

Social  Reforms."     8vo $1.00 

SHERRATT.— The  Elements  of  Hand-Railing  : 

Simplified  and  Explained  in  Concise  Problems  that  are  Easily  Under- 
stood. The  whole  illustrated  with  Thirty-eight  Accurate  and  Origi- 
nal Plates,  Founded  on  Geometrical  Principles,  and  Showing  how  to 
Make  Rail  Without  Centre  Joints,  Making  Better  Rail  of  the  Same 
Material,  with  Half  the  Labor,  and  Showing  How  to  Lay  Out  Stairs 
of  all  Kinds.     By  R.  J.  Sherratt.     Folio.      ,         ,         ,         #2.50 


HENRY  CAREY  BAIRfcj  &  CO.'S  CATALOGUE. 


SYME. — Outlines  of  an  Industrial  Science. 
By  David  Syme.     i2mo.  .         .  .  $2.oo 

TABLES     SHOWING     THE     WEIGHT     OF     ROUND, 
SQUARE,  AND  FLAT  BAR  IRON,  STEEL,  ETC., 
By  Measurement.     Cloth •  63 

THALLNER.— Tool-Steel : 

A  Concise  Handbook  on  Tool-Steel  in  General.  Its  Treatment  in 
the  Operations  of  Forging,  Annealing,  Hardening,  Tempering,  etc., 
and  the  Appliances  Therefor.  By  Otto  Thallner,  Manager  in 
Chief  of  the  Tool-Steel  Works,  Bismarckhiitte,  Germany.  From  the 
German  by  William  T.  Brannt.  Illustrated  by  69  engravings. 
194  pages.     8vo.     1902. $2.00 

TEMPLETON.— The  Practical  Examinator  on  Steam  and  thd 

Steam -Engine: 

With  Instructive  References  relative  thereto,  arranged  for  the  Use  of 

Engineers,  Students,  and  others.     By  William  Templeton,  En. 

gineer.     i2mo.  ........         #1.00 

THAUSING.— The  Theory  and  Practice  of  the  Preparation  of 
Malt  and  the  Fabrication  of  Beer: 
With  especial  reference  to  the  Vienna  Process  of  Brewing.  Elab- 
orated from  personal  experience  by  Julius  E.  Thausing,  Professor 
at  the  School  for  Brewers,  and  at  the  Agricultural  Institute,  Modling, 
near  Vienna.  Translated  from  the  German  by  William  T.  Brannt, 
Thoroughly  and  elaborately  edited,  with  much  American  matter,  and 
according  to  the  latest  and  most  Scientific  Practice,  by  A.  Schwarz 
and  Dr.  A.  H.  Bauer.  Illustrated  by  140  Engravings.  8vo.,  815 
pages $10.00 

THOMPSON.— Political  Economy.     With  Especial  Reference 
to  the  Industrial  History  of  Nations  : 
By  Robert  E.  Thompson,  M.  A.,  Professor  of  Social  Science  in  the 
University  of  Pennsylvania.      i2mo.  .         .         .         .         $1.50 

THOMSON.— Freight  Charges  Calculator: 

By  Andrew  Thomson,  Freight  Agent.     241110.        .        .        #1.25 

TURNER'S  (THE)  COMPANION: 
Containing  Instructions  in  Concentric,  Elliptic,  and  Eccentric  Turn- 
ing; also  various  Plates  of  Chucks,  Tools,  and  Instruments;  and 
Directions  for  using  the  Eccentric  Cutter,  Drill,  Vertical  Cutter,  and 
Circular  Rest;  with  Patterns  and  Instructions  for  woiking  them, 
l2mo #1.00 

TURNING  :   Specimens  of  Fancy  Turning   Executed  on  the 

Hand  or  Foot- Lathe :  ( 

With  Geometric,  Oval,  and  Eccentric  Chucks,  and  Elliptical  Cutting 

Frame.     By  an  Amateur.     Illustrated  by  30  exquisite  Photographs. 

4*0. #2.50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.  27 


VAILE. — Galvanized-Iron  Cornice-Worker's  Manual : 

Containing  Instructions  in  Laying  out  the  Different  Mitres,  and 
Making  Patterns  for  all  kinds  of  Plain  and  Circular  Work.  Also, 
Tables  of  Weights,  Areas  and  Circumferences  of  Circles,  and  other 
Matter  calculated  to  Benefit  the  Trade.  By  Charles  A.  Vaile. 
Illustrated  by  twenty-one  plates.    4to.         .  *  .         .         $5.00 

VILLE. — On  Artificial  Manures  : 
Their  Chemical  Selection  and  Scientific  Application  to  Agriculture. 
A  series  of  Lectures  given  at  the  Experimental  Farm  at  Vincennes, 
during  1867  and  1874-75.     By  M.  Georges  Ville.     Translated  and 
Edited  by  William  Crookes,  F.  R.  S.     Illustrated  by  thirty-one 

engravings.    8vo.,  450  pages $6.00 

VILLE.— The  School  of  Chemical  Manures  : 
Or,  Elementary  Principles  in  the  Use  of  Fertilizing  Agents.  From 
the  French  of  M.  Geo.  Ville,  by  A.  A.  Fesquet,  Chemist  and  En- 
gineer. With  Illustrations.  i2mo.  .  .  .  .  $1.25 
VOGDES. — The  Architect's  and  Builder's  Pocket-Companion 
and  Price-Book : 
Consisting  of  a  Shoit  but  Comprehensive  Epitome  of  Decimals,  Duo- 
decimals, Geometry  and  Mensuration  ;  with  Tables  of  United  States 
Measures,  Sizes,  Weights,  Strengths,  etc.,  of  Iron,  Wood,  Stone, 
Brick,  Cement  and  Concretes,  Quantities  of  Materials  in  given  Sizes 
and  Dimensions  of  Wood,  Brick  and  Stone;  and  full  and  complete 
Bills  of  Prices  for  Carpenter's  Work  and  Painting;  also,  Rules  for 
Computing  and  Valuing  Brick  and  Brick  Work,  Stone  Work,  Paint- 
ing, Plastering,  with  a  Vocabulary  of  Technical  Terms,  etc.  By 
Frank  W.  Vogdes,  Architect,  Indianapolis,  Ind.  Enlarged,  revised, 
and  corrected.     In  one  volume,  368  pages,  full-bound,  pocket-book 

form,  gilt  edges $2.00 

Cloth         .  I.50 

VAN  CLEVE.— The  English  and  American  Mechanic : 
Comprising  a  Collection  of  Over  Three  Thousand  Receipts,  Rules, 
and  Tables,  designed  for  the  Use  of  every  Mechanic  and  Manufac- 
turer. By  B.  Frank  Van  Cleve.  Illustrated.  500  pp.  i2mo.  $2.00 
VAN  DER  BURG.— School  of  Painting  for  the  Imitation  of 
Woods  and  Marbles : 
A  Complete,  Practical  Treatise  on  the  Art  and  Craft  of  Graining  and 
Marbling  with  the  Tools  and  Appliances.     36  plates.     Folio,  12x20 

inches #10.00 

WAHNSCHAFFE.— A  Guide  to  the  Scientific  Examination 
of  Soils : 
Comprising  Select  Methods  of  Mechanical  and  Chemical  Analysis 
and  Physical  Investigation.  Translated  from  the  German  of  Dr.  F. 
Wahnschaffe.  With  additions  by  William  T.  Brannt.  Illus- 
trated by  25  engravings.  121110.  177  pages  .  .  .  #1.50 
WALTON.— Coal-Mining  Described  and  Illustrated: 
By  Thomas  H.  Walton,  Mining  Engineer.  Illustrated  by  24  Jarg? 
and  elaborate  Plates,  after  Actual  Workings  and  Apparatus.      £5.00 


28         HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE. 


WARE.— The  Sugar  Beet. 
Including  a  History  of  the  Beet  Sugar  Industry  in  Europe,  Varietie 
of  the  Sugar  Beet,  Examination,  Soils,  Tillage,  Seeds  and  Sowing 
Yield  and  Cost  of  Cultivation,  Harvesting,  Transportation,  Conserva 
tion,  Feeding  Qualities  of  the  Beet  and  of  the  Pulp,  etc.  By  Lewi* 
S.  Ware,  C.  E.,  M.  E.     Illustrated  by  ninety  engravings.     8vo. 

WARN.— The  Sheet-Metal  Worker's  Instructor: 

For  Zinc,  Sheet-Iron,  Copper,  and  Tin-Plate  Workers,  etc.  Contain- 
ing a  selection  of  Geometrical  Problems ;  also,  Practical  and  Simple 
Rules  for  Describing  the  various  Patterns  required  in  the  different 
branches  of  the  above  Trades.  By  Reuben  H.  Warn,  Practical 
Tin-Plate  Worker.  To  which  is  added  an  Appendix,  containing 
Instructions  for  Boiler-Making,  Mensuration  of  Surfaces  and  Solids, 
Rules  for  Calculating  the  Weights  of  different  Figures  of  Iron  and 
Steel,  Tables  of  the  Weights  of  Iron,  Steel,  etc.  Illustrated  by  thirty- 
two  Plates  and  thirty-seven  Wood  Engravings.     8vo.  .         $3.00 

WARNER.— New  Theorems,  Tables,  and  Diagrams,  for  the 
Computation  of  Earth-work : 
Designed  for  the  use  of  Engineers  in  Preliminary  and  Final  Estimates 
of  Students  in  Engineering,  and  of  Contractors  and  other  non-profes. 
sional  Computers.  In  two  parts,  with  an  Appendix.  Part  I.  A  Prac- 
tical Treatise;  Part  II.  A  Theoretical  Treatise,  and  the  Appendix. 
Containing  Notes  to  the  Rules  and  Examples  of  Part  I. ;  Explana- 
tions of  the  Construction  of  Scales,  Tables,  and  Diagrams,  and  a 
Treatise  upon  Equivalent  Square  Bases  and  Equivalent  Level  Heights. 
By  John  Warner,  A.  M.,  Mining  and  Mechanical  Engineer.  Illus- 
trated by  14  Plates.     8vo. $3-CO 

WILSON. — Carpentry  and  Joinery: 

By  John  Wilson,  Lecturer  on  Building  Construction,  Carpentry  and 
Joinery,  etc.,  in  the  Manchester  Technical  School.  Third  Edition, 
with  65  full  page  plates,  in  flexible  cover,  oblong       .         .  .80 

WATSON.— A  Manual  of  the  Hand-Lathe  : 

Comprising  Concise  Directions  for  Working  Metals  of  all  kinds, 
Ivory,  Bone  and  Precious  Woods;  Dyeing,  Coloring,  and  French 
Polishing;  Inlaying  by  Veneers,  and  various  methods  practised  to 
produce  Elaborate  work  with  Dispatch,  and  at  Small  Expense.  By 
Egbert  P.  Watson,  Author  of  "  The  Modern  Practice  of  American 
Machinists  and  Engineers."     Illustrated  by  78  engravings.  $1.50 

WATSON.— The  Modern  Practice  of  American  Machinists  and 
Engineers 
Including  the  Construction,  Application,  and  Use  of  Drills,  Laths 
Tools,  Cutters  for  Boring  Cylinders,  and  Hollow-work  generally,  with 
the  most  Economical  Speed  for  the  same;  the  Results  verified  bj 
Actual  Practice  at  the  Lathe,  the  Vise,  and  on  the  Floor.     Togethe? 


HENRY   CAREY   BAIRD   &  CO.'S  CATALOGUE.        29 


with  Workshop  Management,  Economy  of  Manufacture,  the  Steam 
Engine,  Boilers,  Gears,  Belting,  etc.,  etc.  By  Egbert  P.  Watson. 
Illustrated  by  eighty-six  engravings.      i2mo.       .         .         .         $2.50 

WATT.— The  Art  of  Soap  Making  : 

A  Practical  Hand-Book  of  the  Manufacture  of  Hard  and  Soft  Soaps, 
Toilet  Soaps,  etc.  Fifth  Edition,  Revised,  to  which  is  added  an 
Appendix  on  Modern  Candle  Making.  By  Alexander  Watt. 
111.     121110 $3.00 

WEATHERLY.- Treatise  on  the  Art  of  Boiling  Sugar,  Crys- 
tallizing, Lozenge-making,  Comfits,  Gum  Goods, 
And  other  processes  for  Confectionery,  etc.,  in  which  are  explained, 
in  an  easy  and  familiar  manner,  the  various  Methods  of  Manufactur- 
ing every  Description  of  Raw  and  Refined  Sugar  Goods,  as  sold  by 
Confectioners  and  others.     l2mo.      .....         $1.50 

WILL,. —  Tables  of  Qualitative  Chemical  Analysis  : 

With  an  Introductory  Chapter  on  the  Course  of  Analysis.  By  Pro- 
fessor Heinrich  Will,  of  Giessen,  Germany.  Third  American, 
from  the  eleventh  German  edition.  Edited  by  Charles  F.  Himes, 
Ph.  D.,  Professor  of  Natural  Science,  Dickinson  College,  Carlisle, 
Pa.     8vo $1.50 

WILLIAMS.— On  Heat  and  Steam  : 

Embracing  New  Views  of  Vaporization,  Condensation  and  Explo- 
sion.    By  Charles  Wye  Williams,  A.  I.  C.  E.    Illustrated.    8vo. 

$2.50 

WILSON. — First  Principles  of  Political  Economy: 

With  Reference  to  Statesmanship  and  the  Progress  of  Civilization. 
By  Professor  W.  D.  Wilson,  of  the  Cornell  University.  A  new  and 
revised  edition.     i2mo.     .......         $l-S° 

WILSON.— The  Practical  Tool-Maker  and  Designer: 

A  Treatise  upon  the  Designing  of  Tools  and  Fixtures  for  Machine 
Tools  and  Metal  Working  Machinery,  Comprising  Modern  Examples 
of  Machines  with  Fundamental  Designs  for  Tools  for  the  Actual  Pro- 
duction of  the  work;  Together  with  Special  Reference  to  a  Set  of 
Tools  for  Machining  the  Various  Parts  of  a  Bicycle.  Illustrated  by 
189  engravings.     1898 $2.50 

CONTENTS  :  Introductory.  Chapter  I.  Modern  Tool  Room  and  Equipment. 
II.  Files,  Their  Use  and  Abuse.  III.  Steel  and  Tempering.  IV.  Making  Jigs. 
V.  Milling  Machine  fixtures.  VI.  Tools  and  Fixtures  for  Screw  Machines.  VII. 
Broaching.  VIII.  Punches  and  Dies  for  Cutting  and  Drop  Press.  IX.  Tools  for 
Hollow- Ware.  X.  Embossing:  Metal,  Coin,  and  Stamped  Sheet-Metal  Orna- 
ments. XI.  Drop  Forging.  XII.  Solid  Drawn  Shells  or  Ferrules;  Cupping  or 
Cutting,  and  Drawing  ;  Breaking  Down  Shells.  XIII.  Annealing,  Pickling  and 
Cleaning.  XIV.  Tools  for  Draw  Bench.  XV.  Cutting  and  Assembling  Pieces 
by  Means  of  Ratchet  Dial  Plates  at  One  Operation.  XVI.  The  Header.  XVII. 
Tools  for  Fox  Lathe.  XVIII.  Suggestions  for  a  Set  of  Tools  for  Machining  the 
Various  Parts  of  a  Bicycle.  XIX.  The  Plater's  Dynamo.  XX.  Conclusion — 
With  a  Few  Random  Ideas.     Appendix.     Index. 

WOODS. — Compound  Locomotives: 

By  Arthur  Tannatt  Woods.  Second  edition,  revised  and  enlarged 
by  David  Leonard  Barnes,  A.  M.,  C.  E.    8vo.     330  pp.       #3.00 


30        HENRY   CAREY   BAIRD   &   CO.'S  CATALOGUE. 


WOHLER.-A  Hand-Bookof  Mineral  Analysis: 

By  F.  Wohler,  Professor  of  Chemistry  in  the  University  of  Gotthv 
gen.  Edited  by  Henry  B.  Nason,  Professor  of  Chemistry  in  the 
Renssalaer  Polytechnic  Institute,  Troy,  New  York.  Illustrated. 
i2mo. 

WORSSAM.— On  Mechanical  Saws: 

From  the  Transactions  of  the  Society  of  Engineers.  1869.  By  S.  W. 
Worssam,  Jr.     Illustrated  by  eighteen  large  plates.    8vo.          $1.5° 


RECENT   ADDITIONS. 

BRANNT. — Varnishes,  Lacquers,  Printing  Inks  and  Sealing - 
Waxes : 
Their  Raw  Materials  and  their  Manufacture,  to  which  is  added  the 
Art  of  Varnishing  and  Lacquering,  including  the  Preparation  of  Put- 
ties and  of  Stains  for  Wood,  Ivory,  Bone,  Horn,  and  Leather.  By 
William  T.  Brannt.  Illustrated  by  39  Engravings,  338  pages. 
i2mo #3.00 

BRANNT— The  Practical  Scourer  and  Garment  Dyer: 

Comprising  Dry  or  Chemical  Cleaning;  the  Art  of  Removing  Stains; 
Fine  Washing ;  Bleaching  and  Dyeing  of  Straw  Hats,  Gloves,  and 
Feathers  of  all  kinds;  Dyeing  of  Worn  Clothes  of  all  fabrics,  in- 
cluding Mixed  Goods,  by  One  Dip;  and  the  Manufacture  of  Soaps 
and  Fluids  for  Cleansing  Purposes.  Edited  by  William  T.  Brannt, 
Editor  of  "The  Techno-Chemical  Receipt  Book."  Illustrated. 
203  pages.     i2mo. $2.00 

BRANNT.— Petroleum . 

its  History,  Origin,  Occurrence,  Production,  Physical  and  Chemical 
Constitution,  Technology,  Examination  and  Uses;  Together  with 
the  Occurrence  and  Uses  of  Natural  Gas.  Edited  chiefly  from  the 
German  of  Prof.  Hans  Hoefer  and  Dr.  Alexander  Veith,  by  Wm. 
T.  Brannt.  Illustrated  by  3  Plates  and  284  Engravings.  743  pp. 
8vo.  #7-50 

BRANNT. — A  Practical  Treatise  on  the  Manufacture  of  Vine- 
gar and  Acetates,  Cider,  and  Fruit- Wines  : 
Preservation  of  Fruits  and  Vegetables  by  Canning  and  Evaporation ; 
Preparation  of  Fruit-Butters,  Jellies,  Marmalades,  Catchups,  Pickles, 
Mustards,  etc.  Edited  from  various  sources.  By  William  T. 
Brannt.     Illustrated  by  79  Engravings.     479  pp.     8vo.        #6.00 

BRANNT.— The  Metal  Worker's  Handy-Book  of  Receipts 
and  Processes : 
Being  a  Collection  of  Chemical  Formulas  and  Practical  Manipula- 
tions for  the  working  of  all  Metals ;  including  the  Decoration  and 
Beautifying  of  Articles  Manufactured  therefrom,  as  well  as  their 
Preservation.  Edited  from  various  sources.  By  Willi  AM  T. 
Brannt.     Illustrated,     iamo.  $2.50 


HENRY  CAREY  BAIRD  &  CO.'S  CATALOGUE.         31 

DEITE. — A  Practical  Treatise  on  the  Manufacture  of  Per- 
fumery : 

Comprising  directions  for  making  all  kinds  of  Perfumes,  Sachet 
Powders,  Fumigating  Materials,  Dentifrices,  Cosmetics,  etc.,  with  a 
full  account  of  the  Volatile  Oils,  Balsams,  Resins,  and  other  Natural 
and  Artificial  Perfume-substances,  including  the  Manufacture  of 
Fruit  Ethers,  and  tests  of  their  purity.  By  Dr.  C.  Deite,  assisted 
by  L.  Borchert,  F.  Eichbaum,  E.  Kugler,  H.  Toeffner,  and 
other  experts.  From  the  German,  by  Wm.  T.  Brannt.  28  Engrav- 
ings.   358  pages.    8vo. $3-°o 

EDWARDS. — American    Marine  Engineer,    Theoretical   and 
Practical : 
With  Examples  of  the  latest  and  most  approved  American  Practice. 
By  Emory  Edwards.     85  illustrations.     i2mo.      .         .        $2.50 

EDWARDS. — 900    Examination   Questions  and   Answers: 

For  Engineers  and  Firemen  (Land  and  Marine)  who  desire  to  ob- 
tain a  United  States  Government  or  State  License.     Pocket-book 

form,  gilt  edge $1-5° 

FLEMMING.- Practical  Tanning: 

A  Handbook  of  Modern  Processes,  Receipts,  and  Suggestions  for  the 
Treatment  of  Hides,  Skins,  and  Pelts  of  Every  Description.  By 
Lewis  A.  Flemming.  American  Tanner.  472  pp.   8 vo.  (1903)  #4.00. 

POSSELT. — The  Jacquard  Machine  Analysed  and  Explained: 

With  an  Appendix  on  the  Preparation  of  Jacquard  Cards,  and 
Practical  Hints  to  Learners  of  Jacquard  Designing.  By  E.  A. 
Posselt.  With  230  illustrations  and  numerous  diagrams.  127  pp. 
4to. $3-0O 

POSSELT.— The  Structure  of  Fibres,  Yarns  and  Fabrics: 

Being  a  Practical  Treatise  for  the  Use  of  all  Persons  Employed  in 
the  Manufacture  of  Textile  Fabrics,  containing  a  Description  of  the 
Growth  and  Manipulation  of  Cotton,  Wool,  Worsted,  Silk  Flax, 
Jute,  Ramie,  China  Grass  and  Hemp,  and  Dealing  with  all  Manu- 
facturers' Calculations  for  Every  Class  of  Material,  also  Giving 
Minute  Details  for  the  Structure  of  all  kinds  of  Textile  Fabrics,  and 
an  Appendix  of  Arithmetic,  specially  adapted  for  Textile  Purposes. 
By  E.  A.  Posselt.     Over  400  Illustrations,     quarto.       .  $5-oo 

RICH. — Artistic  Horse-Shoeing: 

A  Practical  and  Scientific  Treatise,  giving  Improved  Methods  of 
Shoeing,  with  Special  Directions  for  Shaping  Shoes  to  Cure  Different 
Diseases  of  the  Foot,  and  for  the  Correction  of  Faulty  Action  in 
Trotters.  By  George  E.  Rich.  62  Illustrations.  153  pages, 
lamo. $1.00 


32       HENRY  CAREY   BAIRD   &  CO.'S  CATALOGUE. 

RICHARDSON.— Practical  Blacksmithing : 

A  Collection  of  Articles  Contributed  at  Different  Times  by  Skilled 
Workmen  to  the  columns  of  "  The  Blacksmith  and  Wheelwright," 
and  Covering  nearly  the  Whole  Range  of  Blacksmithing,  from  the 
Simplest  Job  of  Work  to  some  of  the  Most  Complex  Forgings. 
Compiled  and  Edited  by  M.  T.  Richardson. 

Vol.1.     210  Illustrations.     224  pages.     i2mo.  .         .         $1.00 

Vol.11.  230  Illustrations.  262  pages.  i2mo.  .  .  #1.00 
Vol.  III.  390  Illustrations.  307  pages.  i2mo.  ,  .  $1.00 
Vol.  IV.     226  Illustrations.     276  pages.     l2mo.      ,         .         #1.00 

RICHARDSON.— The  Practical  Horseshocr: 
Being  a  Collection  of  Articles  on  Horseshoeing  in  all  its  Branches* 
which  have  appeared  from  time  to  time  in  the  columns  of  "  T  he 
Blacksmith  and  Wheelwright,"  etc.     Compiled  and  edited  by  M.  T. 
Richardson.     174  illustrations #1.00 

ROPER. — Instructions    and    Suggestions   for   Engineers  and 
Firemen : 
By  Stephen  Roper,  Engineer.     i8mo.     Morocco        .        $2.00 

ROPER.— The  Steam  Boiler:  Its  Care  and  Management: 
By  Stephen  Roper,  Engineer.     i2mo.,  tuck,  gilt  edges.        #2.00 

ROPER.— The  Young  Engineer's  Own  Book: 

Containing  an  Explanation  of  the  Principle  and  Theories  on  which 
the  Steam  Engine  as  a  Prime  Mover  is  Based.  By  Stephen  Roper, 
Engineer.     160  illustrations,  363  pages.     i8mo.,  tuck       .  $2.50 

ROSE. — Modern  Steam- Engines: 
An  Elementary  Treatise  upon  the  Steam-Engine,  written  in  Plain 
language ;  for  Use  in  the  Workshop  as  well  as  in  the  Drawing  Office. 
Giving  Full  Explanation  j  of  the  Construction  of  Modern  Steanv 
Engines  :  Including  Diagrams  showing  their  Actual  operation.  To- 
gether with  Complete  but  Simple  Explanations  of  the  operations  of 
Various  Kinds  of  Valves,  Valve  Motions,  and  Link  Motions,  etc., 
thereby  Enabling  the  Ordinary  Engineer  to  clearly  Understand  the 
Principles  Involved  in  their  Construction  and  Use,  and  to  Plot  out 
their  Movements  upon  the  Drawing  Board.  By  Joshua  Rose.  M.  E. 
Illustrated  by  422  engravings.     Revised.  358  pp.       .         .         #6.00 

ROSE.— Steam  Boilers: 
A  Practical  Treatise  on  Boiler  Construction  and  Examination,  for  the 
Use  of  Practical  Boiler  Makers,  Boiler  Users,  and  Inspectors;  and 
embracing  in  plain  figures  all  the  calculations  necessary  in  Designing 
or  Classifying  Steam  Boilers.  By  Joshua  Rose,  M.  E.  Illustrated 
by  73  engravings.      250  pages.     8vo.         .         .         .  #2.50 

3CHRIBER—  The  Complete  Carriage  and  Wagon  Painter: 
A  Concise  Compendium  of  the  Art  of  Painting  Carriages,  Wagons, 
and  Sleighs,  embracing  Full  Directions  in  all  the  Various  Branches, 
including  Lettering,  Scrolling,  Ornamenting,  Striping,  Varnishing, 
and  Coloring,  with  numerous  Recipes  for  Mixing  Colors.  73  Illus- 
trations.    177  pp.     i2mo $i.ort 


DEC  16  1903