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GEOLOGICAL SURVEY

OF

ALABAMA,

EUGENE ALLEN SMITH, Ph. D., State Geologist.

BULLETIN No. 6.
PRELIMINARY REPORT

ON THE

CLAYS OF ALABAMA,

HEINRICH RIES, Ph. D.

SONVILLE,
1900.

To His Excellency,
JOSEPH F, JOHNSTON,
Governor of Alabama.

Dear Sir:—I have the honor to submit herewith, as part of my
biennial report, 1898-9, a report upon the clays of Alabama by Dr.
Heinrich Ries, While the investigations of Dr. Ries here recorded
have been confined to the northern half of the State, and mainly to
one or two formations, they yet embrace the most important and
most accessible of our clay deposits. The kaolins of the granite re-
gion lie at a distance from railroad lines, and the discussion of these
and of the clays of the more recent formations, in the lower half of
the State, will be taken up in a second bulletin.

The present report shows that our clay resources include every
variety, ranging from the best of china clays downward, and there
seems to be no good reason why all these materials should not be
turned into the manufactured products, chinaware, stoneware, fire
brick, ornamental brick, paving brick, tiles, drain pipes, etc., within

our own borders and upon our own ground.

Very Respectfully,

EvucGene A. SMITH.

University of Alabama,
March 15, 1900.

I.

TABLE OF CONTENTS.

Page.

Letter of Transmittal.
Preface scisacessecsemaaauass ate meanumiee ean MERE ITON exeaaneoannen oa E
GENERAL DIscussion OF CLAYS, BY HEINRICH RIES, PH. D.......:.0:000sceeeees 3
OfigitiOf- Clay siicccgcisinstoscousstaaiiomeadishise deceaansneey wesuniawindbaniayeturenemanwemsnyelarssioiieas 3
Geological Structure and Distribution of Clay Deposits... aes, 6
Residual Clays. icc sysaucowucsonsteeanes eerssvaenseeververaiers 6
Sedimentary Clays..............:cccce ceceeeeeeeees eer 7
WISH MEO fhe siasiposduasinanedersesiitics Ladrccheat Cae seetettodaniuduinwinns earpeaaaeaneenss | 8.
Properties Gf Clay ss ais.cccasujics cvesdssaud ve vacensnedeunorsanededescuaatonianeuecs tes’ seers 8
' Chemical Properties........0..0..cc008 ve OF
Allcalies ti Clays. on cccciaaseesacaicd enncada cicnanmnrencenassimedemilndvadte aacseawa guar’ 11
Soluble Alkaline Coinpanads bibeey wis aise 1
Insoluble Alkaline Compounds.............0....:0:ccceeseeescseseeeeeercssseessenens 12
Iron Compounds in Clays..............06 wagitosis (date eptee stnasealanndzatjonangaraple se eceesieyan 13
Lime in Clays................ wixe 16
Magnesia in Clays.... sexy 19
Silica in Clays............... ve 20
Titanic Acid in Clays.......ccccccsescscseceeesseeeeeseeeeneesees asic ae eseineenatneeenbaate 21
Organic: Mattern (Clays si cinsisnacinssncndecebaeenseiy Rates Melaeiy eran aphatinbseeiiiens 22
Water in Clays 22
Moisture 23
Combined Water suo, 24
Physical Properties:of Clays :cecsssisssinasceanveass sacisanonsiseetvacnncanen bens treaevannbetsiv’ 24
Plastigh tydisscsocesioas osorctatinnancaansinn ioemaes sisroninains seeaineaneatecanemsneaeemaeetante euaeen 25
Tensile strength.. ves vee 26
Shrinkage............... ee awe 326
Fusibility of Clays vm 29)
The Thermo-Electric Pyrometer...............:ssccsseeeeeceeceeeeeees cree eesesonsees 31
Segat? Pyraitiids...:.+sis..seserionto ty. anaes onicenureanuheerenene eet yaieetivescemeatey 32
Chemical Effects of Heating Se . 38
Slaking............... Ree 2 seen 98
Absorption...........:0.::cccceeeeeee wee 89
Color of Unburned Clays... cciicissssccsedeoasissevseanessnaasiaveant eosetssedsvaas tiie 39
Mineralogy of Clays..............::0006 Sakirauinnanenanininiaa silasinmmnanaaidensve Rien vaesesiey 40
Kaolinite ssccsn: sesicaewonaneicanecseesteuarcarvnenenvewieswetnns ig srneeaapaaetienvamaneuaeds sts 40
QUALEZ: sisi cnaas rises guicas’sou yesicenitennauannens pixmy ae tena EN Tada eee, MeRsRaRamINEREN 41
Calcite...... 42
Gypsum.... 42
Mica........... 43

Tron Oxide......... sieddles dea topes aaineineemdntcddesisen dee discieglsl saint duldechve Suictinecdatietaaleiaatens 43

vi

Methods employed in Making Clay Analyses................... .
Rational Analysis of Clay........:c.ccccsccecscsssececcesscceaeacesereesecsaneceseuneeasons sees 50
Classification of Clays..........cccccceseeeeeessesceseeeeeanaenansanereseeeeesenaeaaseeseeeanans 57
Mining and Preparation of Clays...........66 cccesssseccseceeeecenceeseeesecasnnnetscusenes 59
Prospecting for Clays..........:ccssesecssesseeesessecneeeeeeeeeeeeeeeereccenereeteneaeenaas 59
Mining of Clays............. fe eee eeeeeee nese eee eeaeenenaeseeneenen ene et nese eee 60
Mining of Kaolin...... siding cadigithjaads Voheestaned eas Seaeneaenmeets gaateniest 61
Washing Of KaOlittecicccccsacacsssinaved enomecornodonearnece’ dooued venues cnn ctitiay teatpauurys 62

II. GEoLtocicAL RELATIONS OF THE CLAYS OF ALABAMA, BY EUGENE A,
SMITH, “PH, “Dsioes seerevavacasecorymestaecnoorsdesunasins sasvenenopencebiyatgnae seeeheansenns cane 69
Archean and Algonkian:. ..:.5..00: Jawcdeveaeteesctaganterseaavaceunasteatsisveonsnens neaay TO.

Cambrian and Silurian Formations.. 73
Subcarboniferous Formation...........:000c:sseeeeeeeeeeeeees a MT
Coal Measures...................- 80
Cretaceous: Formation isc. seaceawcseacwaiasseeigss spies bea ues ssguesoremenvavey evee wedi 81
Russell and, Macon ‘Counties :sscisssseccviens sus susestogerssmnaysctaieaneentavssneeaeears 87
Elmore and Autauga Counties.........0...00......0ec00e a vatieinis BuAdouletivec sista darecinils 88
Bibb: County....23 ces ccnstetwavtndncsnavcduueosuuberpupesteneadidanndvidashwavvecdeeevesvy 90
Tuscaloosa County... 92
Pickens County....... 97
Lamar County...... weve (98
Bayette’ County pp siesde on cuesiges <vasnesiies ones Saves oaachannd dhehundiuncadesesanass Halmmuess 101
Marion County...............0..ccccccesees uginglisvseddmacde dame cmemumisatedea abate koutiens 104
' Franklin County 107
Colbert Coit yes ssacciciioinanana agaaige teesermabiiunaamsinegastlewioemonssonmrdanenia. aes . 109
Lauderdale County 111
SP Ott Ary ss us'cu. sus yheve <ceoainties aetvaceirieh sas se Mia Sle hg kuna buds Hee aR eS 112
III. PRELIMINARY REPORT ON THE PHYSICAL AND CHEMICAL PROPERTIES OF THE
CLAYS OF ALABAMA, BY HEINRICH RIES, PH. D ........ ce ceecec cece eeeeee 114
China (Clays -scvis capsci aatavdnstusiaiaveasgutsgssenste jyswuwigucay an steiina sa tamauinuvncct alana
Rock Run, Cherokee: County isecccscsccmsrsedsansansces, ghnontiipsineundencennendosnna sees
Gadsden, Etowah County...... ....
Kymulga, Talladega County.....
Eureka Mine, DeKalb County
“ “ “ “
La ee EE ETC RETR MRE PR IC
Chalk Bluff, Marion County............cccccccccsesesceceeeeceeeenscteeeeeeseeeseenenenes
er oe ie re acti atah aaa acer etnsveomeeseeRk 127
Near Chalk Bluff, Marion County..........0.....::seceeec ee ceseesececesenseteeeeenes 127
Pearce’s Mill, Marion County...............:0::::ssecssseescssseeceecesssseeeseeueeseees 128
Pegram, Colbert County.......... seve 129
Bre: Clays sscciesn satanovgviese deus Suita eihmevanven he Ventre ct Gel wai area an arene gem teats xebstit 130
Peaceburg, Calhoun ‘County’... :....0...scqvss casswusicszacenuceisiisnesssenanenisteswe nies 134

Oxanna, ee CO 22s Si wiate die oie wis iel TOSS MERRIE Dao a oiaToIsa sain atre SUR Selen SNES 135

Rock Run, Cherokes County (Clays)

seed “« (Bauxites)...
Males Head, Dekalb County..........

Fort Pine fe
Bibbville, Bibb County
Woodstock “& =
Hull’s Station, Tuscaloosa i

J. C. Bean, "
Pearce’s Mill, Marion County.............0..0002
“ “ “ “
Pegram, Colbert County.............00. sings ant pling Sloe Seek ncaa heap G Adda 157
Flint Clay, “ eo
Pottery or Stoneware Clays.........ccccccccessesseee oes
White, Blount County....0......... ce ceeeeer ia
Rock Run, Cherokee County..........c:::cccccceeesenes shtditeteeesaet Gd aelaesesets cies
Chalk Bluff, Elmore County.......:......:.66 rs
“ « “ “ =
Edgewood, oa AOS « pebebuaavg odaistais Sans wt-doatnie's
Ly . WED © se Ucicdiseitskisiuiok it neee wee see
Coosada, a Oe Heetihiae sulaceceney seh ge aeeN ie@ iba camaceaandes Aepeeonds
Cribb’s Pottery, Taiealoces sprigs sp heiedhedlitecatsakybienivammaets due eoudasvanniv on cars 166
J. C. Bean, zs
be “
Roberts’ Mill, Pickens County re
Bedford, Lamar COUNY..weispcuicds coves ees ceicacamennedwessct ieee ateooa avian aleeas tates
Fernbank, ‘“ rer crore os pa bauagev ene vas meueanieRRednes
W. Dey, Fayette —
“
Shirley's Mill,“ i
H. Higgins, “
S. E. of Hamilton, Marion County.......0.....cccccceeeee cecueseceeeees feuasenaests 179
Th. Rollins, Franklin County.......... .. 180
Pegram, Colbert County.... . 180
Brick Clays....... seeped daaaaeligiansvedes eiielavaclee sss ausieg dewees xepe 181
Brick Shales, Birmingham, Jefferson County............. eecahieuaniaepucadeemienes 184
Paving Brick Shale, Coaldale, ‘ SO peeeessuavelomeanncdaeten ieabastnmeres 186
Pearce’s Mill, Marion County............c00::eeeeeeeeeeeeeee eee a .. 186
Ten-Mile Cut, Tuscaloosa County............. .. 187
Oxford, Calhoun County (Dixie Pottery)... wee 188
Shirley’s Mill, Fayette County........... a tgdian sama bnmulieaiuons.cundesibevivanien oes) cataoies 189
Chalk Bluff, Elmore Gounty...........0..ccssseceessscesccsecceessessseasesseaeeeasees .. 190
Woodstock, Bibb County..........0. ccccscsesssecssseeseceesesseeeeee scaneeneeseesenens 191
Birmingham, Jefierson County gelacchabe gor dgee saves iate Sauidoumenuntpeeneteete Stead 192
Argo, - iedeuedidanisesnaanaes emoeveredamrauanmendscueyinsiatdmieeees 193
Miscellaneous Clavs..............cccssee0 wis buss weanvatdet ans evak duoubemreeenets 193

W. D. Bagwell, Fayette County...............00 savisevsanebvetanta avaeeceancuteny, LOK

Bexar, Marion Couuty...............ccsescccsccsssscessseessse cae coneeeesserssaesesseee

“ “ “

ity “ “

Glen Allen, Marion County
W. J. Beckwith, Colbert County...
Utilization of Clay for Portland Cement

PREFACE.

Clay is one of the most abundant materials found in
the earth’s crust, and occurring as it does in every
country, in almost every geological formation from
** nearly the oldest to the youngest, and frequently in
positions easy of access, it is not to be wondered at
that these, conditions, aided by the peculiar properties
which it possesses, have caused this material to be-
come one of the most useful and valuable products of
the earth.

The value of clay is still more readily understood
when the statistics of its production are known. Thus
in 1897, the total value of clay products made in the
United States alone was $60,911,641.00, distributed :
as follows:

Common brick,.... 5.6.5 cee ee ee cent eeeee $ 26,353,904
Presged Grid ian cieues eestosenes «vax ans 3,931,336
Vitrified paving brick.... ...... Pe ra 8,582,037
Ornamental brick.... 2.2.6. .eeeeee Fe ie esta ana 685,048
Mire briGks sive ses4s 4054 eee senes ayaa 4,094,704
Drain tile.... 2,623,305
Sewer pipe... 4,069,534
Mera, COC es 2 2o-d.cc 810 ee. Siar bieRGer ees Siok eis Seeherd 1,701,422
Hire Proofing; cocdauccseso0 RHEE: AAG VaR 1,979,259
Tile other than drain............ cece eeene 1,026,398
MiscellaneousS........ weeceee ce eeee cee a 1,413,835
Pottery css seewnecaan sored 9,450,859

Up to the present time the rank of Alabama as a
clay producing state has not been very high, owing
largely to the lack of information concerning its clay
resources, and in the following report an endeavor has
been made to furnish as much information as possible
concerning the characters of many of the Alabama

clays.
‘ HEINRICH RIES.
March 1, 1900.

I
GENERAL DISCUSSION OF CLAYS,

By HEINRICH RIES.

ORIGIN OF CLAY.

Clay is to be met almost every where, and while it
varies in form, color and other physicial properties,
nevertheless it always forms a pasty or plastic mass
when mixed with water, by virtue of which it may be
molded into any shape, which it retains when dried;
furthermore when exposed to a high temperature it
hardens to a rock like mass. These two properties,
the plasticity and the hardening when burnt are what
make clay of such inestimable value ‘to man.

Pure clay or kaolin is composed entirely of the min-
eral kaolinite, which is a hydrated silicate of alumina.
It rarely happens, however, that clay is perfectly pure,
for owing to the nature of its formation from another
rock as will be explained later, it is very apt to have
other minerals mixed in with it. These foreign min-
erals may sometimes be present in such quantities as
to completely mask the character of the kaolinite.

We can therefore define clay as a mixtureof kaolin-
ite with more or less quartz and other mineral frag-
ments, especially feldspar and mica, the whole posses-
sing plasticity when mixed with water, and becoming
hard when burned.

The so called flint clays form an exception to the
above, for while they often approach pure kaolin in
composition, still they are almost devoid of plasticity
when ground and mixed with water.

Kaolinite is a secondary mineral resulting from the
decomposition of feldspar. The feldspars are a group
of silicate minerals of ~ather complex composition,

4 GENERAL DISCUSSION OF CLAYS.

with orthoclase, the potash feldspar, serving as the
type of the group, as well as being the commonest
species.

Under the influence of chemical action. which may
be the result of weathering or in some cases probably
of acid vapors ascendning from the interior of the
earth, the feldspar becomes decomposed, and the result
of this is that the potash of the feldspar is removed
partly in the form of solube carbonate, or perhaps
‘silicate, or even fluoride, while the alumina and silica
remain and unite with water to form the hydrated
silicate of alumina, kaolinite, whose composition is
expressed by the formula Al, O 3, 2S10,, 2H,0., or
in the proportion of silica, 47.30 per cent.; alumina,
39.80 per cent.; water 13.90 per cent.

The change can be illustrated still better by the fol-
lowing in which the first column indicates the com-
position of the feldspar, the second the amount of
water taken up in the process of decomposition, the
third, the amount of matter removed in solution, and
the fourth the relative amounts of the three ingredi-
ents of kaolinite. "

Feldspar. Added. Dissolved out. Kaolinite.

Alumina.... ... .... «s 18.3 artocate 0.0 18.3
Silica.... Be aE 64.8 ceca 41.8 23.0
Potash: i445 &iaw amen ae 16.9 alate 16.9 sate
Watericors sae eres a Sia 6.4 sass 6.4

Many clays approach quite closely to kaolinite in
their composition, and in some the percentage of
alumina even exceeds the theoretic amount, by one or
two per cent., and is evidently not due to errors of an-
alysis.

It has been suggested by some that this may be due
to the presence of a certain amount of pholerite, the
amorphous variety of kaolin,* and while this is pos-
sible the same composition might: be shown by a cer-
tain amount of bauxite or alumina hydrate mixed in
with the clay.

* Wheeler, Clays of Missouri, Missouri Geological Survey, XI.

ORIGIN OF CLAYS. 5

None of the Alabama clays thus far analyzed indic-
ate this exceptional composition.

Knowing the mode of origin of kaolinite it will at
once be seen that the purity of the kaolin depends on
the nature of the parent rock. Feldspar often forms
large veins of considerable purity, and nearly free
from other associated minerals, and its decomposition
in such cases would give rise to deposits of pure or
nearly pure kaolin. In point of fact the purest clays
known have with few exceptions been formed in this
manner. More frequently quartz and mica are com-
mon accessory minerals, and remain intermixed with
the kaolinite, both of them being more resistent to
weathering than the feldspar. When these or other
minerals occur in the kaolin they have to be separated
from it as much as possible by washing.

Clays, which occur at or close to the locality in
which they have been formed, are called “residual
clays”. They represent some of the purest types of
clay known as well as the most impure. The upland
region of the Southern States is underlain by a great
area of feldspathic, granitic and gneissic rocks which
have decomposed to a ferruginous clay of residual
nature, and one that is used extensively in the South.
for the manufacture of common brick.

In the general wearing down of the land su~face
which. is continually taking place the particles of
residual clay are washed down into the lakes and
oceans and deposited there as sediments, thus giving
rise to what are known as sedimentary clays. They
are usually, far more plastic than the residual clays,
especially the purer ones.

From the nature of their formation, we should sel-
dom look for kaolins of sedimentary origin, and when
they do occur they have probably been derived from
large areas of very feldspathic rock or possibly from
limestones which had an appreciable percentage of
silicate of alumina in their composition, in which case
the lime ecarborate would be carried off in solution,
and the clay components of the rock be left behind as
an insoluble residue. It is seldom that sedimentary

6 GENERAL DISCUSSION OF CLAY.

clays exhibit such remarkale purity as those from
Chalk Bluff, Alabama, or the plastic ball clays of
Florida.

The clays of the Cretaceous and Tertiary forma-
tions, which underlie the Coastal Plain, as well as the
Palaeozoic shales found in Alabama, are all of sedi-
mentary origin.

GEOLOGICAL STRUCTURE AND DISTRIBU |
TION OF CLAY DEPOSITS.

BESIDUAL CLAYS.

The mode of origin of these has already been ex-
plained. They may occur either in the form of a broad
mantle overlying the bed rock and showing a variab‘”
thickness as well as extent, or they may occupy the
position of a vein cutting across the strike of the other
rocks, or extending at times with the bedding or lami-
nation of them. :

Residual clays are commonly made up of a mixture
of angular grains which are chiefly undecomposed
mineral matter, and clay particles which are mostly
of sufficient fineness to remain suspended in water for '
an almost indefinite period. There is also generally
a gradual transition from the fully formed clay at the
surface to the f-esh rock below, whose decomposition
has given rise to the plastic mass above. ,

The depth below the surface at which the unaltered
rock is encountered may be as little as three to four
feet, while in some regions where the surface has been
little eroded, and decomposition has been active, the
thickness of the residual clay may exceed one hundred
feet.

The structure of the parent rock such as stratifica-
tion or lamination is at times often noticeable in the
lower portion of the residual deposits, and in some
cases it may even be preserved right up to the surface.

Residual deposits of the vein type result commonly
from the decomposition of veins of granite or feldspar.
They vary in width, from a few inches to several hun-

STRUCTURE AND DISTRIBUTION OF CLAY DEPOSITS. 7

dred feet, and their vertical extent depends in most
cases on the depth to which the weathering action has
progressed.

Veins of kaolin seldom show great length, and when
followed along the surface not uncommonly pinch
out in both directions. They are often separated

more or less sharply from the country rock, and this.

distinct line of demarkation is preserved even when

the wall rock itself is decomposed. They further- —

more frequently branch and at times contain lenses
of quartz, which resist the weathering agencies and
stand out in bold relief on the surface. It rarely pays
to work a vein under six feet in width.

Deposits of kaolin of the type just described: should
not be confused with sedimentary deposits of white
clay, which are usually of a much greater extent
than the vein formation.

SEDIMENTARY CLAYS.

These occur in the form of beds, which are either
close to the.surface or interstratified with other de-
posits which have been accumulated in water, such as
sandstone or limestone. They are not unfrequently
interbedded with coal deposits and many a coal seam
has a fire clay floor. Sedimentary clays are, as a rule
more homeogeneous than residual ones, and contain
probably a greater portion of fine particles. They are
also more plastic, and frequently contain much dis-
seminated organic matter. Furthermore, they do not
pass gradually into the underlying rock as residual
clays do, and indeed bear no relation, in a genetic
sense, to the rocks upon which they rest.

When sedimentary clays become compressed by the
weight of overlying sediments, they assume the
character of hard or consolidated rock, and are known
as shale. Shales therefore simply represent the finest
clay sediment which has become consolidated.

On grinding to a powder and mixing with water,
shales become just as plastic as other clays. By
mentamorphism, (that is heat and pressure developed

8 GENERAL DISCUSSION OF CLAYS.

by mountain making processes) taking place in the
crust of the earth, a shale may lose its chemically com-
bined water, develop a cleavage, and become converted
into slate. It is then no longer possible to develop
any plasticity in the material.

It is not to be understood that all sedimentary clays
are of a homogeneous structure throughout. Some
beds may exhibit a wonderful similarity of composi-
tion throughout extended areas, while again ther. may
be a wide variation in the character of any bed within
narrow limits. Apart from this variation laterally,
there may also be a vertical one ‘n cases where the de-
posit is made up of a number of beds, one over the oth-
er, each showing distinctive characters. With such oc-
currences it is possible to obtain several different
grades of clay from the same pit. Such conditions are
apt to be the rule rather than the exception.

A not uncommon phenomon in many of the coastal
plain formations is the occurrence of large lenses of
clay, free from grit) surrounded by beds of sandy clay
or even sand. :

DISTRIBUTION.

Clays and shales occur in practically every geologi-
cal formation with the exception of the oldest. Most
of those which are older than the Creataceous are
hard and shale—like in their nature, while those
of the Cretaceous and Tertiary on the other hand are
usually soft and plastic, but deposits of Creataceous
and also Tertiary shales are known.

The geological age of a clay or shale is no indication
of its quality, and it is only of use at times for a means
of comparison between two beds situated near each
other, but even here it is not altogether a safe guide.

The geological relations of the clays of Alabama
are treated somewhat more in detail below in a separ.
ate chapter.

PROPERTIES OF CLAYS.

These fall into two classes, i. e. (1) Chemical and
(2) Physical. Two clays may correspond in their

CHEMICAL PROPERTIES OF CLAYS. 9

widely in their physical characters, and therefore act
entirely opposite when used for the manufacture of
clay products.

Pure clay or kaolin would be composed entirely of
kaolinite, the hydrated cilicate of alumina. These
two terms are often confounded and it is well to em-
pahasize the fact that kaolinite refers to the mineral
species, while the term kaolin is applied to the mass.
Pure kaolin has not thus far been found, although
deposits containing as much as 98 per cent. of it are
known, and the othe» two per cent. consists of foreign
matter. The kaolin therefore contains a variable
amount of mineral ‘mpurities mixed in with the kao-
linite or the clay substance, as it is some times called,
and these impurities may affect both the chemical and
the physical properties to a variable extent, depend-
ing upon the quantity and the kind of them present.
The clay substance is always present but in a
variable amount, and it stands in no direct relation to
the plasticity, except in so far that the latter is lost
when the combined water is driven off.

The amount of clay substance in clays ranges from
5 or 10 per cent. to 98.5 per cent.

The chief impurities in kaolin are quartz, feldspar
and mica, but in other clays the number of mineral
species present may indeed. be large.

CHEMICAL PROPERTIES.

The chemical composition of a clay directly influ-
ences its fusibility, and the color to which it burns.

The compounds which may be found in clay are
silica, alumina, iron oxide, lime, magnesia, potash,
soda, sulphuric acid, phosphoric acid, manganese
oxide and organic matter. Compounds of chromium
and vanadium may also be present at times in small
amounts... All’ of these substances are not present in
every clay, but most of them are.

Pure clay would contain silica, alumina and com-
bined water, but the purest clay known commonly
contain at least traces of iron oxide, lime and alkalies.

10 GENERAL DISCUSSION OF CLAYS. —

Alumina, organic matter and water are practically
the only non-volatile constituents, which do not exert
a fluxing action on the clay in burning, and the inten-
sity of this fluxing depends partly on the amount of
fluxes, and partly on the temperature at which the
clay is burned.

It is the custom to divide the impurities of clay into
those which are fluxing, and those which are non-flux-
ing. rk é

Pure clay is very refractory. The kaolinite com-
posing it contains two molecules of silica and one
molecule of alumina. A higher percentage of sil‘ca
tends to increase the fusibility up to a certain point,
provided it is in a finely divided condition. above this
point the refractoriness of the clay increases steadily
with the addition of silica.

Other substances are far more powerful fluxes than
the silica however, and these fluxes contain not only
elements but also definite chemical compounds or
mineral species.

The influence of fluxes increases not only with the
amount present but also with the state of division,
they being more active, the more finely they are divid-
ed. If the fluxing material is present in large grains,
these will only exert a fluxing action on their upper
surface, while the single grains alone will for a while
act more like quartz grains i. e. as diluents of the
shiinkage.. The minerals which may be present and
serve as fusible impurities are commonly mica, feld-
spar, hornblende, pyroxene, garnet, quartz, calcite,
gypsum, iron oxide and manganese, and the elements
contained in these constituting the active fluxing
agents are alkalies, iron oxide, lime and magnesia.

Opinions differ somewhat in regard to the order of
their relative effectiveness, but it is probably given
above, the alkalies being the strongest.

The amount and kind of fluxes which it is desirable
for a clay to contain depends on the use to which it is
to be put. Ifa vitrified ware is desired then the
fluxes should be present in appreciable amount, say
10 to20 per cent., depending upon the relativestrength

CHEMICAL PROPERTIES OF CLAYS. oh, |b

of the fluxing impurity. Refractory clays, on the
other hand, should contain a low amount of fusib'e
substances. Porcelain clays might have as high a per-
centage of fluxes as 5 or 6 per cent., provided they did
not exert a coloring action on the clay.

a

ALKALIES IN CLAYS.

The alkalies usually contained in clays are potash,
soda and ammonia. 2 Aa
Ammonia is a very common constituent, ‘of moist
clay and is absorbed by the latter with great avidity;
indeed it is largely responsible for the characteristic

oder of clay.*

If thetammonia remained in the clay, it would act
as a strong flux, but its volatile nature renders it
harmless, for it passes off as a vapour at a temper--
ature considerably below dull redness, and in fact may
even volitilize with the moisture of the clay during the
early stages of burning.

Potash and soda on the other hand, which volati-
lize only at a high temperature, are present in almost
every clay from the smallest amount up to 9 or 10 per
cent. and of these potash is by far the commoner of the
two. Their variable percentage may be caused by ‘the
presence of more or less undecomposed feldspar, of
which crthoclase, the common species, has nearly 17
per cent. of potash while the other feldspars contain
varying amounts of soda.

These alkalies may be present in the clay in the
form of either soluble or insoluble compounds, the
latter being represented by feldspar, mica, or other
minerals, while the soluble ones are usually the result.
of their decomposition.

Soluble alkaline compounds may be found in almost
any clay, but they are rarely present in large amounts, .
and their chief importance lies inthe fact that. they
are often responsible for the formation of an efflor-
escence or white coating on the surface of the ware,
they having become concentrated on the surface by the

*F, Senft, Die Thon Substanzen, p. 29.

12 GENERAL DISCUSSION OF CLAYS.

evaporation of the moisture of the clay. They may be
rendered insoluble by the addition of chemicals to the
clay. In addition to its unsightliness the efflores-
cence may interfere with the adhesion of a glaze ap-
plied to the surface of the ware.

Soluble alkaline sulphates are powerful fluxes and
they also cause blistering of the ware, if the clay is
heated sufficiently high to decompose the compound
and permit the escape of sulphuric acid gases.

In some clays containing sulphate of iron, this com-
pound may be decomposed by chemical reaction tak-
ing place in the clay; the sulphuric acid, which is
thus set free, is apt to attack the alumina of the clay
substance and if potash, soda, or ammonia ‘s present
there is formed an alum of potash, soda or ammonia,
which can often be detected by the taste which ic im-
parts to the clay.

Insoluble alkaline compounds. Feldspar andi mica
which are the commonest of rock forming minerals
are the two important sources of insoluble alkaline
salts in the clay.

The feldspars are complex silicates of alumina and
potash, or alumina, lime and soda. Orthoclase is the
only species furnishing potash and contains about 17
per cent. of it while the lime-soda feldspars have from
4 to 14 per cent. of soda depending on the species.

Orthoclase is the common feldspar, and next to it
come albite end oligoclase with 12 and 14 per cent. of
soda respectively. ,

The micas are complex silicates of alumina with
either lime or magnesia or potash. Muscovite, the
common species, contains nearly 12 per cent. of pot-
ash, and may at times also contain soda. While the
potash feldspar fuses completely at about 2300° Fahr.,
the potash mica alone is very refractory and unaf-
fected by a temperature of 2550° Fahr., and though
it probably serves as a flux, it is not definitely known
at just what temperature its action begins.

The alkaline silicates on account of their fluxing
properties are frequently at an advantage, especially
if in the form of feldspar, as they serve in burning to

CHEMICAL PROPERTIES OF CLAYS. 13

bring the particles of the clay together into the dense
hard body, and also permit of the ware being burned
at a lower temperature. If present in kaolins to the
_. extent of several per cent. it is no detriment, provided
uv iron is present; an excess of feldspar, however,
when added to a white burning clay will tend to pro.
duce a creamy tint.

In the manufacture of porcelain, white earthen
ware, encaustic tiles and other products made from
kaolins or white burning clays, and having a white
body, which is impervious, or nearly so, the alkalies
for the fluxing of this body are added in the form of
feldspar. :

Much feldspar is mined in this country for potters
use, but all of it is the ortholase or potash feldspar.

IRON COMPOUNDS IN CLAYS.

Iron is not simply a fluxing impurity, but it is also
the great coloring agent of clays in either their burned
or unburned condition, and furthermore when in the
form of the hydrated oxide or limonite it may serve
to increase the absorbtive power of clay. *

The compounds in which iron may exist in the clays
are as follows: Oxides :—limonite, hematite, magne-
tite, ilmenite. Silicates:—mica, hornblende, garnet,
etc. Sulphides:—pyrite and marcasite. Sulphate :—
melanterite. Carbonate :—-siderite. i

_The iron oxides, limonite and hematite, are present
in all clays, and may be introduced by percolating
waters or be set free by the deccomposition of any of
the iron-bearing silicates which the clay may contain.
Not infrequently they are distributed through the
clay in a very finely divided condition, or may form a
thin film around the other mineral grains. Limonite
tends to color .the clay (unburned) brown or yellow,
while hematite imparts a red color to it, and carbon-
ate of iron may give gray tints.

The more sandy. the clay the less the amount of the

* A. BE. Smith, Alabama Geological Survey, Agricultural Report, p. 45.

‘

4 GENERAL DISCUSSION OF CLAYS.

limonite required to produce any given intensity of
color.

Mica is found in most clays, and hornblende and
garnet are probably wanting in few, while the pyrite
is often present in many clays, especially i in stoneware
and fire clays, its yellow, glittering, metallic particles
being easily recognizable. When large, the lumps of
pyrite can be extracted by hard-picking, but if very
small, they can only be separated by washing. Un-
der weathering influences the pyrite changes to sul-
phate of iron. In all of the iron-bearing minerals the
iron is present in’either the ferrous or the ferric stage
of oxidization, and the fusibility of the clay is in-
fluenced somewhat by this fact, for ferrous com-
pounds are more easily fusible than ferric ones. In
the burning of the clay the ferrous salt will be con-
verted into the ferric state, provided the action of the
fire is oxidizing. But if it is reducing the clay will
fuse at a lower temperature.

The action of weathering agent in nature is often
sufficient to oxidize the iron in clays so that more
ferric than ferrous iron will be found in most of them.
This change is often noticeable in many clay banks
where the upper, and at times more porous layers, are
colored red or yellow, while the lower layers ure blue
or bluish gray..

It should be roticed, however, that a gray color may
be produced ‘by the presencce of organic matter, and
the same material present in a dense clay, to which
the air can not get access, may serve to retard the oxi-
dation of the iron. Whenever iron exists in clay in
combination with s‘lica it is present probably as a
complex silicate, for pure ferric silicate is very rare
in nature.

Ferric hydrate increases the absorbing power of
clay for both gases and liquids, but iti as well as the
carbonate change to the oxide in burning.

The general tendency in burning is to convert the
iron compounds into ferric oxides, provided a certain
temperature, depending on the fusibility of the clay,
is not exceeded, for in every clay the iron seems to re-

CHEMICAL PROPERTIES OF CLAYS. 15

'
‘

turn to the ferrous condition as the point of vitrifica-
tion is approached. This change is accompanied by
a liberation of oxygen, which is responsible for the
active swelling and blistering of the clay, which takes
place as the point of viscosity is approached.

If treated to an oxidizing fire, the presence of fer-
rous salts in clay may not be considered, provided the
heat is raised high enough to oxidize them, byt the
rapidity with which the temperature is raised is im-
portant, for when the heat is increased rapidly the
outer portion ‘of the clay tends to shrink and become
dense before the air has had time to enter and oxidize
the iron in the center of the clay body, the latter re-
maining in ferrous state. This is the cause of black
cores sometimes seen in bricks whose exterior is red.

Unburned clay may be yellow, blue, brown, red or
gray in color, depending on the relative amount of
ferrous and ferric salts present, for iron is the one ele-
‘ment above all others which by itslf colors clays.

The same variety of shades and colors may be pro-
duced in burning. Ferrous oxide alone produces a
green color when burned while ferric oxide alone may
give red or purple, and mixtures of the two may pro-
duce yellow, cherry red, violet, blue and black.*

Segar found that combinations of ferric oxide with
silica had a red or yellow color§ while similar com-
pounds of the ferrous salts showed blue or green.

The color to which any given clay burns may also
depend on the jntensity of the firing. Thus with mod-
erate burning the iron may color a clay yellow or yel-
lowish red, with harder firing this will pass into deep
red, and on still more intense heating to blue or black,
this latter color is to be seen on breaking open the arch
brick in many kilns, but the surface of these same
brick may also get black, due to ashes and cinders
from the fire sticking to them.

The amount of ferric oxide permissible or desirable
depends on the use to which the clay is to be put.

*Keramik, p. 256.
2Notizblatt, 1874, p. 16.

16 GENERAL DISCUSSION OF CLAYS.

The clays which are used for making white ware
should not contain over one per cent ferric oxide.
And those with even three-quarters of one per ccnt.
are apt to burn grayish at a high temperature, such
as 2700 deg. Fahr. It is true that the reddish color-
ation of a small percentage of iron would be neutral-
ized if any excess of carbonate of lime were present,
but in this case even we should not get a pure white
tint, but a yellowish one.

Brick clays should contain sufficient iron oxide
to give a good red color to the ware wlien burned.

The bleaching of the iron coloration by the presence
of lime will be mentioned later, an excess of alumina
also tends to exert a decolorizin® action upon the iron
contained in the clay.

LIME IN CLAYS.

Lime is a most wide-spread constituent of clays, and
occurs either in a finely divided state or else in the
form of pebbles. An excess of lime in the clay in the
former condition causes it to pass into marl, and in
certain regions such clays are extremely abundant.

Lme may occur in clays either as a constituent of
silicate minerals such as feldspar; in the form of car-
bonate as exampled by calcite or dolomite; or thirdly
it may be present as a sulphate, which is the mineral
gypsum.

The first two classes of compounds include minerals
which are primary constituents of the clay, but the
third type, gypsum, is usually of secondary origin, be-
ing the result of chemical processes, which took place
in the clay mass.

The condition of lime is important, for in one case,
it may be desirable, and in another it may do injury.

The presence of lime as a constituent of some silicate
mineral is not infrequent, especially if the clay has
been derived wholly or in part from crystalline rocks,
such as gneisses and granites. The common feldspar,
orthoclase, contains no lime, but the other species of
feldspar do, and in addition there are other lime bear-

CHEMICAL PROPERTIES OF CLAYS. 17

ing silicates which are apt to be met with in most of
the impure clays.

_ When present as a silicate, lime acts as a flux, and
is less liable to exert a decolorizing action on the clay -
than carbonate of lime. Bleaching action is caused
by the formation of a double silicate of iron and lime,
when the clay reaches a temperature approaching vit-
rification, and the color developed is either yellow, or
yellowish green, according to the intensity of the
firing.

Carborate of lime is an abundant constituent of
some clays, and its presence, if over three or four per
cent., can usually be detected by the effervescence
which is producd when muriatic acid is poured on the
clay. This compound of lime is far more injurious
than the silicate, although, if present in the clay, ina
finely divided condition, it may not only be harmless
but even desirable, provided there is not an excess of
it, for clays with as much as twenty to twenty-five per
cent. of lime carbonate have been used for making
common or even pressed brick and somtimes earthen-
ware. It is well, however, to try and keep the amount
lower than this if possible. Highly calcareous clays
have often found a use in making of slip glazes.

If the carbonate of lime is present in the form of
pebbles, a most undesirable effect is produced, for it
is well known that when heated to redness, the com-
pound is broken up into oxide of lime and carbonic
acid gas; this oxide of lime, when cooled, absorbs mois-
ture from the atmosphere and slakes, the result. being
a swelling of the material and a consequent splitting
of the brick. Now if the clay be heated to a tempera-
ture sufficent to decompose the carbonate of lime, but
not high enough to make it unite with any free silica
present, the lime of course slakes on cooling. It is con-
sequently imporatnt either to burn the clay sufficently
or remove the lime pebbles from the clay by screening
or by some other method before using.

For a high grade ware, calcareous clays are seldom
employed, but in the manufacture of brick and terra-

18 GENERAL DISCUSSION OF CLAYS.

cotta, they are frequently utilized either because no
others are available or to obtain a buff colored ware.

Some soft body porcelains have an appreciable
amount of lime, much of the Hungarian containing
from five to fifteen per cent. of CaO.* The bone china
made in England at the present day also contains
lime and some white earthen ware manufacturers use
lime instead of feldspar.

Much buff ware is now made from semirefractory
clays, which, on account of their low percentage of
iron, burn to a creamy color.

The one objection ito highly calcaeous clays is that
the points of incipient fusion and vitrification (see
Fusibility of Clays) lie so close together that it
is not safe to burn them hard without running
the risk of fusing them. Experiments have shown
however, that it is possible to separate these two
points, by the addition of quartz and feldspar to the
clay, of sand containing a large percentage of these
two minerals.

In addtion to lowering the fusibility of clay, lime
also affects the fusion and absorptive power, thus
Segar found$§ that limy or marly clays required us-
ually only twenty to twenty-four of water to convert
them from a dry condition to a workable mass, where-
as other clays needed twenty-eight to thirty per cent.
of water to accomplish the same result. In burning
the calcareous clays have not only their combined.
water to lose, but also the carbonic acid gas, and con-
sequently the bricks are more apt to be light and po-
rous unless they can be burned to vitrification. The
shrinkage of calcareous clays is also less than that of
others, and it sometimes happens that this shrinkage
is not only zero, but that the brick even swells.

Many clays contain lime in the form of gypsum, the
hydrated sulphate of lime. It generally results from
the action, on carbonate of lime, of sulphuric acid set
free by the oxidation and leaching of pyrite in the clay.

*Sprechsaal, 1896, p. 2.
?Hecht, Thonindustrie Zietung.
#2 Thonindustrie Zietung, 1877, p. 181.

CHEMICAL PROPERTIES OF CLAYS. 19

When in large amounts, gypsum discloses its presence
by the formation of transparent crystals or crystallne
masses, whose surface shows a pearly lustre; at other
times it forms as parallel fibres which fill cavities or
cracks in the clay. Gypsum may prove to be a very
injurious impurity even when in small amounts, es-
pecially if the clay is not burned to vitrification.

In the first place it serves as a fluxing impurity,
sedondly, it is dissociated at high temperatures,
and the escape of the sulphuric acid causes blistering
of the ware, and thirdly, although nearly insoluble in
water, nevertheless small amount of it may be brought
to the surface of the ware in solution by the evapora-
tion of water and there left in the form of a white coat-
ing.

Kaolins commonly have very little lime, but in many
common brick and stone ware clays, it frequently
ranges from one to three per cent.

MAGNESIA IN CLAYS.

Magnesia is a constituent of many minerals, and yet
it seldom occurs in large quantities, the amount in
most of them rarely exceeding two per cent.

It may occur in the same classes of compound as
lime i. e. silicates, such as mica, chlorite, hornblende
and pyroxene; in carbonates, such as dolomite and
magnesite; and in sulphates, such as epsom salts.

The silicates are, no doubt, the most important
source of magnesia, for mica, chlorite, and hornblende
are all common constituents of the more impure clays.
They are scaly minerals of complex composition and
contain from 1 to 25 per cent. of magnesia. The
mica is frequently to be noticed in the sandy seams of
the clay, while the other portions.of the deposit may
be quite free from it. Hornblende and pyroxene are
to be looked for mostly in clavs derived from the dark
colored igneous rocks, and indeed the two:latter min-
erals not only furnish magnesia, but by their decom-
position furnish also iron oxide to the clay.

Dolomite, the double carbonate of lime and mag-

20 GENERAL DISCUSSION OF CLAYS.

nesia, may be present in some clays derived from mag-
nesian limestone, while the sulphate of magnesia or
epsom salts when present, may aid in the formation
of a white coating on the surface of the ware; its pre-
sence can sometimes be detected by the bitter taste
which it imparts to the clay.

The effects of magnesia in clays are considered to be
the same as those produced by lime.

SILICA IN CLAYS.

Three types of silica may be recognized in clay, i. e.

ist. Quartz.

2nd. That which is combined with alumina and
water in kaolinite.

3rd. That which is combined with one or more
bases, forming silicate minerals, such as feldspar,
mica, ete.

In chemical analysis the first and third are some-
times grouped together under the name of sand, or at
times erroneously spoken of as free silica.

The sand is practically insoluble in sulphuric acid
and caustic soda and this fact is utilized in the ration-
al analysis of clay.

Few clays, so far as known, are free from quartz,
but it is present in variable amounts in different ones.
A minimum of .2 of one per cent. has been recorded
from New Jersey* while the average in the Wood-
bridge fire clays is five per cent.

In the Missouri flint clays, a minimum of .5 of one
per cent., is recorded, while the sand: percentage is 20
to 43 per cent. in the St. Louis fire clays, and 20 to 50
per cent. in the Loess clays.§

27 samples of Alabama clays contained from 5 to 50
per cent. of insoluble residue.

70 North Carolina clays had from 15.75 per cent.
to 70.48 per cent. of insoluble residue.

In European clays similar variations are observ-
able. The most important effect of silica or sand is

*G. H. Cook, Clays of New Jersey, 1878, p. 273.

§ Wheeler, Missouri Geological Survey, XI, page 54.

CHEMICAL PROPERTIES OF CLAYS. 21

that as it increases the plasticity, tensile strength, and
air shrinkage tend to decrease. .In fact silica es-
pecially if present abundantly in large grains, may
cause an expansion of the clay in burning.

Quartz serves as a flux at very high temperatures,
but at lower ones it tends to increase the refractori-
ness of the clay, and this property is governed some
what by the size of the quartz grains and the amount
of fluxing material which will fuse at lower tempera-
tures.

Sand acts as a diluent of the shrinkage in air drying
and also in burning up to a certain point depending
upon the fusiblity of the constituent grain.

In the burning of low grade clay, the quartz grains
tend to act as a skeleton and preserve the form of the
mass, while the fluxing impurity by their fusion bind
the whole together.

TITANIC ACID IN CLAYS.

Titanium generally occurs in clays in the form of
the mineral rutile (titanic oxide). It has always
been looked upon as a rare element and a non-detri-
mental impurity, but the idea of its rarity has pro-
bably resulted from the fact that it is not commonly
determined or looked for in the ordinary quantitative
analysis. Its effect on the fusibility of clay has never
been thoroughly understood, although it has seemed
probable that its action was somewhat analogous to
that of silica.

The experiments of Seger bave indicated that when
a hundred parts of kaolin and 6.65 per cent. titanic
oxide were heated to above melting point of wrought
iron, the resulting mass was densely sintered, and
showed a dark blue fracture.

13.3 per cent. added to a hundred parts of kaolin
gave a deep blue enamel at the same temperature,
while an equal amount of kaolin with the addition of
10 per cent. of silica burned to a snow white mass at
the same temperature and did not fuse. From this it
will be seen that the actions of titanium and silica at
high temperatures are not exactly alike.

22 GENERAL DISCUSSION OF CLAYS.

ORGANIC MATTER IN CLAYS.

Organic matter affects not only the color of clay but
_ also’ its plasticity, absorptive power and tensile
strength.

It is present in clays either in the form of finely
divided pieces of plant tissue or larger fragments of
stems or leaves, which settled in the clay during its
deposition, and have since become wholly or partly
converted into lignite. All surface clays contain
plant roots, but these exert iittle effect other than to
aid the percolation of surface waters.

Clays colored by organic matter and containing no
iron, burn white, as the plant tissue burns off at
bright redness; if such a clay, however be heated too
quickly, the surface of it becomes dense before all of
the organic matter has had opportunity to escape from
the interior, and the latter remains dark colored.

Organic matter may also mask the presence of iron
so that the clay, instead of burning white, will burn
red at a temperature of above that at which the or-
ganic matter passes off, below that temperature the
vegetable matter will tend to keep the iron reduced.
The clay from Fernbank, Lamar County, Alabama,
contains 6.40 per cent of ferric oxide, and 2 to 24
per cent of organic matter, but in the raw material, the
latter hides the former. Organic matter exercises an
important influence on the plasticity, often increasing
it to an enormous degree, it also tends to elevate the
tensile strength, the clay just mentioned showing 185
pounds per square inch, but high plasticity does not
always indicate the presence of much organic mate-
rial.

In the weathering of clays organic matter by its
slow oxidation, aids in breaking them up by the es-
cape of the carbonic acid gas.

WATER IN CLAYS.

All clays contain two kinds of water :—

1st. Hygroscopic water or moisture (mechanically
absorbed ) .

2nd. Chemically combined water.

CHEMICAL PROPERTIES OF CLAYS. 23

The moisture in air dried clays may be as low as .5
per cent. and reach 30 to 40 per cent. in those freshly
taken from the bank. In the air dried specimens in
the Alabama samples tested, it varied from .12 per
cent. to 3.4 per cent.

In air drying most of the moisture is expelled, and
this is accompanied by a shrinkage of the clay, which,
in the case of the Alabama samples, was usually from
2 to 7 per cent., but in one case it reached 14 per cent.

The air-shrinkage of the clay ceases however before
all the moisture passes off, the reason for this being
that the shrinkage ceases when the clay particles have
come in contact with each other, but there may still
remain spaces between them which hold the water by
capillarity, and the brick will contiue to lose weight
but not in size, until all of this water has been driven
off.

In practice it is this latter portion of the moisture
that evaporates during the first period of the burning
known as water smoking.

The air shrinkage of a clay varies with the nature
of the material. Sandy clays usually show the least
shrinkage, and of this kind the coarse grained ones
diminish the least in size, while highly plastic clays
usually show a high contraction in volume.

The amount of water, which a dry clay needs to
develop its maxium plasticity is a variable quantity.
Plastic clays absorb a large amount, but a lean clay
and fine grained one may do thesame. Asa very gen-
eral rule it may be stated that lean clays absorb from
twelve to twenty per cent. of water, while fat clays
anywhere from twenty to fifty per cent., and the more
water a clay absorbs the more it has to part with in
drying and the greater will be its shrinkage.

If green ware is dried too rapidly it may split, not
only from differential shrinkage between the exterior
and the interior surface, but the rapid escape of steam
‘may, in the first stage of the burning, tend to burst
the ware.

Highly aluminous clays do not always absorb the
most water, nor are they the most plastic, and some

24 GENERAL DISCUSSION OF CLAYS.

clays low in alumina and high in organic matter are
not only ‘highly plastic but also absorb a large quanti-
ty of water.

In the manufacture of clay products the moisture
is partly expelled by exposing the ware to the sun or
putting it in heated tunnels or rooms, while the last
traces of moisture ave driven off in the early stages of
burning.

Moisture may play another important and injurious
role in clay working by its tendency to dissolve the sol-
uble salts in the clay and bring them to the surface in
drying, where they are left in the form of a white
coating. It may also permit the acids which are con-
tained in the fire gases of the kiln, to act on the min-
eral ingredients of the clay, and thus form soluble
compounds, especially clorides and sulphates.

Combined water is present in every clay. In pure
kaolin there is nearly 14 per cent. of it, in other clays
the percentage depends on the amount of clay base and
the presence of other hydrated minerals, such as
limonite.

Combined water is driven off at a low red heat, and
when this occurs the clay suffers an additional shrink-
age. It is a curious fact that although the combined
water does not determine the degree of plasticity of
‘the clay, nevertheless when once driven off the clay
‘can no longer be rendered plastic. The greater the
amount of combined water, the greater the shrinkage,
and in ‘the burning the Alabama clays it varied from
24 to 12 per cent.

PHYSICAL PROPERTIES OF CLAYS.

These are fully as important as chemical ones, if
not more so, plasticity for instance being a character
of enormous value.

The physical characters which are of the most im-
portance from the practical standpoint, are plasticity,
fusibility, shrinkage, tensile strength, slaking, absorp-
tion and density.

PHYSICAL PROPERTIES OF CLAYS. 25
PLASTICITY.

- This is the property by virtue of which a clay can be
moulded into any desired form when wet, which shape
is retained by it when dry.

. Just what the cause of plasticity is still remains to
be definitely proven, although several theories, some
of them very reasonable ones, have been advanced. It
is an exceedingly variable property and we can find all
stages in the transition from the highly plastic clay
to the slightly coherent sand. Clays, which posses
little plasticity are said to be lean, while highly plastic
ones are called fat.

Pure or nearly pure kaolins are nearly always lean,
while clays low in kaolinite may be highly plastic, thus
for instance the clay from Chalk Bluff, and the stone-
ware from Prattville, containing respectively 36.50
and 26.98 per cent. of alumina are both lean, while the
clays from Fayette Court House and Fernbank con-
taining only 19.68 and 13 per cent. of alumina respec-
tively are both highly plastic.

Cook has shown that the plasticity of some kaolins
may be increased by grinding them, the result being
to tear apart the little particles of clay which were
bunched or clustered together and thus permit a great-
er mobility of the grains or scales of clay over each
other.

Mica decreases the plasticitv of clay, and if, in a
finely divided condition, tends to make it flaky when
wet. _ =

Plasticity, whatever its cause, is an important pro-
perty from a commercial standpoint and highly inter-
esting from a scientific one. The amount of water re-
quired to.develop the maximum plasticity varies. If
too little is added the clay cracks in moulding and is
stiff and hard to-work; if too much is mixed in with
the clay it becomes very soft and retains its shape with
difficulty. Lean clays usually require less water to
produce a workable mass than plastic ones.

The Alabama clays require from 25 to 30 per cent.
of water to develop their maximum plasticity.

26 GENERAL DISCUSSION OF CLAYS.

TENSILE STRENGTH.

The tensile strength or the binding power of a clay
often stands in relation to its plasticity, but not al-
ways. It exerts an important effect in connection
with the cracking of the ware in drying. The com-
mon method of determining it is to form the plastic
clay into briquettes of the same shape as those used in
the testing of cement. When air-dried they are tested
in the regular cement testing machine, and their ten-
sile strength per square-inch is determined. Before
breaking, the cross section of the briquette must be
carefully measured, as the clay shrinks in drying and
the tensile strength per square inch has to be calcu-
lated from this sectional area. _ .

The tensile strength of air-dried clays is extremely
variable. In kaolins it is from 5 to 10 pounds per
square inch; in brick clays 60 to 75 pounds per square
inch and even 100 pounds; in pottery clays from 150
te 175 pounds.

Some very plastic clays show as much as 200 and
300 pounds per square inch, and a tensile strength of
even 400 pounds has been recorded.

The strongest Alabama clay were the highly plastic
one from Chalk Bluff, which had a maximum tensile
strength of 384 pounds per square inch, while the
Choctaw County one showed only 5 pounds per s4uare
inch.

The Alabama clays were all ground and passed
through a thirty mesh sieve before testing.

Very fine grained clays seem to be lacking in tensile
strength as they are in plasticity.

SHRINKAGE.

All clays undergo a shrinkage in drying and an ad-
ditional shrinkage in burning, the first is known as
air —, the second as fire-shrinkage. Some clays shrink
most in drying, others most in burning, and conse-
quently the amount is variable and depends on the
amount of water absorbed, on the amount of lime in

PHYSICAL PROPERTIES OF CLAYS. 27

the clay, the quantity ef organic matter, the size of the
grain, and the amount of combined water.

The amount of water absorbed, and the texture in-
fluence the air-shrinkage which begins as soon as the
water commences to evaporate from the clay. It has
already been mentioned that a clay keeps on losing in
weight after the shrinkage has ceased, and this fact is
well shown by the following experiments on some Ala-
bama samples.

oe clay was from property of J. C. Bean, Sec. 31, T. 20,
» 11 w.

After moulding, the clay weighed............... 35.698 grams. .
At end of 24 hours the shrinkage was 11}
per cent. and the weight... 0... 30.891 us
At end of 48 hours, shrinkage 12 per cent.,
WISN bisscccscmcdaenseiienestianatiuen cas da cesid Meena "29.588 ss
At ete of 6 daye, shrinkage 12 per cent.,
2

eight
Ate end of 8 days, shrinkage 12 per cent.,
WEDD b atciiipingspnsaiets uawedunnautimeg as: nanegeroseeas "29,140 He
At ead of 12. days, shrinkage 12 per ‘cent.,
WOIPD bes iiasiianaanctes pamianmada sawat egaranyiereaeseae "29.093 ae

Throughout this period the clay was kept exposed to a temper-
ture of 70° Fahr.

The shrinkage is generally equal in all three direc-
tions, and consequently only the linear shrinkage is
given. The greater the shrinkage of a clay the more
danger there is of its cracking and warping in burn-
ing, and when there is any apprehension that this may
occur, an attempt is made to prevent it by the addition
of grog (burned clay) which diminishes the shrinkage.

Coarse grain clays having larger pores permit the
water to escape more rapidly, and hence can be dried
more quickly than fine grained ones, from which the
‘water can not very readily escape. If the
drying of fine grained clays is hastened, the surface
shrinkage is more rapid than that of the interior and
cracking ensues. We might perhaps expect that on
account of their greater porosity, the fine grained
clays would absorb more water, and consequently
shrink more in drying. but the Alabama clays do not
always bear out this fact.

The fire shrinkage generally commences when the

28 GENERAL DISCUSSION OF CLAYS.

combined water begins to pass off, and it may be just
as variable as the air shrinkage. In fine grained clays,
as those from near Prattville, the shrinkage from
burning was found to be comparatively uniform,
while on the other hand moderately fine grained
kaolin from Rock Run shrank more rapidly as it ap-
proached the temperature of vitrification.

Sometimes the clay instead of shrinking during the
burning appears to expand; and this is especially the
case with very quartzose ones, fer the quartz has the
property of expanding at high temperatures. This
expansion of siliceous clays may sometimes be respon-
sible for the presence of cracks jn the burned ware.

As the addition of quartz to diminish the shrinkage
also tends to decrease the tensile strength of the clay,
there will be a certain limit beyond which it must not
proceed.

Organic matter and combined water tend to in-
crease the shrinkage in burning, but lime has the opo-
site ten lency.

Clays containing a large amountof feldspar will, in
stead of showing a steady shrinkage up to the temper-
ature of complete vitrification, often exhibit a tempo-
rary increase of volume when the fusing point of the
feldspar is reached.

The shrinkage of most clays in burning does -‘ot
proceed regularly and steadily up to the temperature
of vitrification, for some clays attain their maximum
density at a comparatively low temperature, below
that at which thev vitrify. Thus the plastic clay of J.
C. Bean, near Tuscaloosa, attains its maximum
shrinkage at cone 5, but does not vitrify until cone 27.

Between the point at which the moisture seems to
pass off and that at which the combined water.begins
to escape, the clay shrinks little or none at all, and

PHYSICAL PROPERTIES OF CLAYS. 29

consequently the heat can be raised rapidly in this in-
terval, but above and below these two points it must
proceed slowly to prevent cracking or warping of the
ware.

FUSIBILITY OF CLAYS.

It can be said in general, that other things being
equal, the fusibility of a clay will increase with the
all the fuxing impurities do not act with the same in-
approximate statement however, for in the first place
all the fluxing impurities do not act with the same in-
tensity, and of two clays containing the same amount
and kind of fluxes, that one which has the finer grain
will usually fuse at the lower temperature, in addition
to this the condition of the fire, whether oxidizing or
reducing, also exerts an effect.

White mica tends to increase the refractoriness of
a clay, and to exert very little fluxing action even at
moderatly high temperatures.

As a clay is gradually heated, it not only shrinks,
but also begins to harden. At the temperature at
which the combined water begins to pass off, the im-
pure clays acquire such a degree of hardness that they
can no longer be scratched by a knife; but ‘n the case
of purer clays, the temperature must be raised much
higher to obtain this same degree of hardness. This
condition is brought about by the clay particles be-
ginning to soften under the action of the heat, in other
words it represents the very first stages of melting or
incipient fusion, and in this condition the clay parti-
cles stick to each other, and bind the whole together
into a solid mass. In clays which have been burned to
incipient fusion, tht particles are however still rec-
ognizable. If the temperature be increased, a vari-
able amount, depending upon the clay, the result is

30 GENERAL DISCUSSION OF CLAYS.

that all of the particles become sufficently soft to per-
mit their adjustment into a condition of greater com-
pactness, leaving no interspaces, or in other words,
the clay becomes impervious. This condition is
spoken of as virtification, or complete sintering. The
particles of the clay are no longer recognizable, and
the maximum shrinkage has been reached. With a
further elevation of the temperature the clay mass
fusses completely, and becomes viscous or flows.

We therefore can recognize three stages in the burn-
ing of the clay, i. e., incipient fusion, vitrification and
viscosity. *

The points of incipient fusion and viscosity may be
within 75 degrees Fahr. of each other as in calcareous
clays, while in some fire clays they may be as much as
500 or 600 degrees apart, and furthermore the point
of vitrification does not necessarily lie midway be-
tween the two.

Most clays show a difference of from 200 to 400
degrees Fahr. between the points just mentioned, and
it can be easily understood the farther apart these
two points, the safer will it be to burn the clay, for it
is not always possible to control a kiln within a range
of a few degrees of temperature, and therefore in burn-
ing a mass of ware to vitrification if this point lies too
near that of viscosity, there is danger of overstepping
it and reaching the latter.

The fusibility of a clay depends on:

1. The amount of fluxes.

2. Size of the grain of the refractury and the non-
refractory constituents.

3. The condition of the fire, whether oxidizing or
reducing.

*These three terms have been suggested by H. A. Wheeler, Vitrified
Paving Brick, 1895.

PHYSICAL PROPER1IES OF CLAYS. 31

Attempts have been made to express the relative
fusibiliy of clays numercally, and this number has
been called the refractory quotient by Bishop* and
the fusibility factor by Wheeler.§ In both cases, the
figure is obtained by using the non-fluxing elements
of the clay for the numerator, and the fluxing impuri-
ties as a denominater; and in the case of the second
formula, the fineness of the grain was also taken into
consideration. As this mode of expressing the fusi-
bility has not come into general use, the reference is
simply given here.

On the other hand, it is customary to express the
fusibility of the clay in degrees of temperature, and
this temperature is measured by one or another form
of pyrometer, whose principle depends on the fusion
of alloys or single metals; thermo-electricity; fusion
of an axtificial mixture; spectro photometry; expan-
sion of gases or solids; ete. Many of these are only
applicable at lower temperatures, others are largely
influenced by the personal equation, and only two or
three of the most important will therefore be mention-
ed here.

THE THERMO-ELECTRIC PYROMETER.

Le Chatelier’s Thermoelectric pyrometer depends
on the measurement of a cu~rent generated by the
heating of a thermo-pile. The latter consists of two
wires, one of platium, tbe other an alloy, 90 per cent.
platinum and 10 per cent of rhodium, twisted together
at their free ends for a distance of about an inch, while
the next foot or two of their lenth is enclosed in a fire
clay tube so that when the couple is inserted into the

*Die Feuerfesten Thone, p. 71, 1876.
8 English and Mining Journal, March 10, 1894.

32 GENERAL DISCUSSION OF CLAYS.

furance only the end which is held near the body
whose temperature is to be measured, will receive the
full force of the heat. The two wires connect with a
galvanometer, the deflection of whose needle increases
with the temperature at the point of the free end of the
wire couple. As at present put on the market, the
thermo-electric pyrometer, costs about $180 and this,
together with the delicacy of the galvanometer, has
tended to restrict its use. There is no reason however
why one should not be made and put on the market for
a much lower price. It is not necessary that the re-
cording instrument should be in immediate vicinity
of the kiln, but it may be kept in another room where
it is safe from dust and rough handling, and wires can
extend from there to tlc kiin. This pyrometer is con-
sidered to be accurate to within 10 degrees Fvhr.

SEGER PYRAMIDS.

These consists of different mixtures of kaolin and
fluxes, which are compounded so that there shall be
a constant difference between their fusing points.
Segar’s series were numbered from one to twenty, and
the difference between any twoiconsecutive numbers
is 36 degrees Fahr. <A later series introduced by Cra-
mer runs from .01 to .022 with a difference of 54 de-
grees Fahr. between their fusing points,
and in addition the higher numbers. in
the Segar’ series have been extended from
number twenty up to number thirty-six. As these
cones have been recently recalibrated, the fusing
points of the various numbers together with their
composition is given herewith.*

* Taken from a recently issued circular of Thon industrie Saboratorium in
Berlin, where the cones are and were originally made.

PHYSICAL PROPERTIES OF CLAYS. 33

No. or Fusion ‘F'UsIoN
ConE. CoMPosITION. Point Point
4 Cent. Faur.
0.5 Naz O eee | 2 SiO.
022 590 1094
0.5 Pb O 1 Be Og
0.5 Naz O 2.2 Si Os
021 0.1 Aly Os 620 1148
0.5 Pb O 1 Bz Os
0.5 Nag O 24 Si Oz
020. 0.2 Als Os 650 1202
0.5 Pb O 1 Be Os
0.5 Naz O 2.6 Si Ov
019 0.3 Als Os » 680 1256
0.5 Pb O a 1 Bz Os
0.5 Naz O 28 SiO, .
018 0.4 Aly Os 710 1310
0.5 PbO 1 Be Og
0.5 Naz O 3 Si O2
017 0.5 Als Og 740 1364
0.5 Pb O 1 Bz Os
0.5 Naz O 3.1 Si Oz
016 0.55 Als Os 770 1418
0.5 Pb O 1 Bz Os
0.5 Naz O 3.2 Si Oz
015 0.6 Als Og 800 1472
0.5 PbO 1 By Og
0.5 Naz O 8.3 Si Os
014 0.65 Als Os 830 1526
0.5 PbO 1 By, Og
0.5 Naz O 3.4 Si O2
013 0.7 Ale Oz 860 1580
0.5 Pb O 1 Be Os
0.5 Naz O 3.5 Si O2
012 0.75 Alp O3 890 1634
0.5 Pb O 1 Bez Os
0.5 Naz O 3.6 Si Oz
011 0.8 Ale Os 920 1680
0.5 Pb O 1 By Os
0.3 Kz O 0.2 Fee O3 3.50 Si Oz
010 950 1742
0.7 Ca O 0.3 Als Og 0.50 Be Us
0.3 Ke O 0.2 Fes Os 3.55 Si Oo
09 970 1778
0.7 Ca O 0.3 Al: Og 0.45 Bz Os

34
No. oF
ConE
0.8 KE, O
08
0.7 Ca O
0.3 Kz O
07
0.7 Ca O
0.3 Kz O
C6
0.7 Ca O
0.38 K. O
05
0.7 Ca O
0.3 Kz, O
04
0.7 Ca O
0.3 K, O
03
0.7 Ca O
0.3 Ke O
02
0.7 Ca O
0.3 K, O
01
v7.7 Ca 0
0.3 Ke O
1
0.7 Ca O
0.8 K, O
2
oT Ca 0
0.3 K, O
3
0.7 Ca O
0.8 Ke O
4
0.7 Ca O
0.38 Ke O
5
0.7 Ca O
0.3 K, O
6
0.7 Ca O

GENERAL DISCUSSION OF CLAYS.

ComPosiTIONn.

0.2 Fes Os

0.3 Ale Og
0.2 Fes Os

0.3 Als Og
0.2 Fes Og

0.3 Als Os
0.2 Fee Os

0.3 Ale Os
0.2 Fes Og
0.3 Als Og
0.2 Fes O3
0.3 Ale Og
0.2 Fez Os
0.3 Als Og
0.2 Fes Og
0.8, Als Og
0.2 Fes Og
0.3 Ale Og
0.1 Fes Os
0.4 Ale Os
0.05 Fes Os

0.45 Als Os

0.5 Ale Og

0.5 Al, Os

5 Si Oz

6 Si O2

. Fusion

Point
CENT.

990

1010

1030

1050

1070

1090

1110

1130

1150

1170

1190

1210

1230

1250

Fusion
Point
FauR,

1814

1850

1994

2030

2066

2102:

2138

2174

2210:

2246

2282-

10

Ad

12

13

“14

15

16

17

18

19

20

0.7 CaO
0.38 Ky O3

0.7 Ca O
0.3 Kz, O

0.7 Ca O
0.3 K, O
0.7 CaO
0.3 Ks; O
0.7 CaO
0.3 Kz O

0.7 Ca O
0.3 Ke O
0.7 CaO

0.3 Kz O

PHYSICAL PROPERTIES OF CLAYS.

ComposiTi0n.

0.8 Als Og

0.9 Ale Og

1.0 Alz Og

1.2 Alo Os

1.4 Al, O3

1.6 Als Og

1.8 Als Og

2.1 Als O3

2.4 Als O3

2.7 Alo Og

3.1 Als Og

3.5 Als Og

3.9 Als Og

7 Si Oz

8 Si Oz.

9 Si O2

10 Si O2

12 Si O2

14 Si Oz

16 Si Og

18 Si O2

21 Si Os,

24 Si Oo

27 Si Oz

31 Si Os.

35 Si Oo

39 Si O2

Fusion
Point
Cent.

1270

1290

1310

1330

1350

1370

1390

1410

1430

1450

1470

1490

1510

15380

35

Fusion
Point
Faur,

2318

2354

2390

2426

2462

2498

2534

2570

2606

2642

2678

2714

2750

2786

22

23

24

25

26

27

28
29
30
31
32
33
34
35
36

GENERAL DISCUSSION OF CLAYS.

CoMPosiTION.

44 Si Oo.

49 Si Oz

54 Si O2

60 Si O,

66 Si Oz

72 Si Oz

200 Si. Og

10 Si O2
8 Si O2
6 Si O2
5 Si O2
4 Si O2
3 Si Oz
2.5 Si Oo
2 Si O2
2 Si O2

Fusion
Point
CEnT.

1550

1570

1590

1610

1630

1650

1670

1690
1710
1730
1750
1770
1790
1810
1830
1850

Fusion
Point
Faur.

2822

2858

2894

2930

2966

3002

3038

3074
3116
3146
3182
3218
3254
3290
3326
3362

The theory of these pyramids is that the cone bends
over as the temperature approaches its fusing point,

and when this is reached, the tip touches the base.

If

the heat is raised too rapidly, those cones which con-
tain much irop swell and blister and do not bend over,
and the best results are obtained by the slow softening

of the cone under a gradually rising temperature.

For practical purposes these cones are considered
sufficiently accurate.
In actual use they are placed in the kiln at a point

PHYSICAL PROPERTIES OF CLAYS. 37

where they can be watched through a peep-hole but
at the same time will not receive the direct touch of
the flame from the fuel. It is always well to put two
or more cones in the kiln so that warning can be had
not only of the approach of the desired temperature
but also of the rapidity with which the temperature
is rising.

In order to determine the temperature of a kiln sev-
eral cones of separated numbers are put in,as for ex.
.07,1,and5. Suppose .07 and 1 are bent over in burn-
ng but 5 is not affected, then the temperature of the
kiln was between one and five; the next time 2, 3, and
4 are put in, and 2 and 3 may be fused but 4 remain
unaffected, indicating that the temperature reached
the fusing point of three.

These pyramids have been much used by foregin
manufacturers of clay products and are coming into
use in the United States. Numbers .01 to 10 can be
obtained for one cent each from Prof. E. Orton, Jr.,
Ohio State University, Columbus, Ohio.

It is rather difficult to compare the thermo-electric
pyrometer with Seger pyramids and say that either
one or the other is better. The latter are well adapted
to judge the completion of the burning. That is it
may take the same amount of heat to burn a certain
ware to the proper condition, as it does to bend over
cone 5,so that when the latter goes over the burning is
done.

The cones do not however show whether the temper-
ature of the kiln is r’sing steadily or fast at one time
and slow at another, or again whether or not it may
have dropped temporarily. .

All of these last mentioned conditions are shown by
the thermo-electric pyrometer, and a comparison of

38 GENERAL DISCUSSION OF CLAYS.

conditions during burning, with the results obtained,
may lead to a discovery of those conditions that will
produce the best product.

CHEMICAL EFFECTS OF HEATING.

While the fusion of a clay may be looked upon in
part as a chemical action, there are other changes
which take place.in the clay. before the temperature
of fusion is reached. These changes are:

The driving off of the chemically combined water.

The burning of the organic matter.

The change of limonite to hematite by the loss of
its combined water.

The oxidization of pyrite to sulphate which by
further heating loses its sulphur and is also converted
into hematite.

The driving off of carbonic acid from any carbonates
of lime or magnesia which may be present.

The general effect of these changes is first to make
the clay more porous, but subsequently to increase its .
shrinkage, and in addition the color of the clay is
changed.

A chemical interaction between the components of
the clay only begins with incipient fusion.

SLAKING.

Clays, when thrown into water, break up more or
less completely, or in other words, they slake. The
process is simply one of mechanical disintegration,
which, however, has important practical bearings.
Some homogeneous clays on being immersed split into
a number of angular fragments, while others flake off
into scaly particles, while still others crumble down to
a powder. This slakirg action proceeds slowly or

PHYSICAL PROPERTIES OF CLAYS. 39

quickly depending on the toughness or density of the
clay. Some clays slake completely in two or three
minutes, while others may be little effected by an
immersion in water of an hour or two.

The practical importance of slaking is noticed first
in the case of clays which have to be washed for mark-
eting, for the quicker they fall apart when they are
thrown into water, the more rapid and sometimes the
more thoroughly will be the elimination of the impuri-
ties.

In the tempering the easy slaking of a clay is also
of importance, permitting it to be more easily broken
up and the more thoroughly mixed with water.

ABSORPTION.

This varies with the amount of organic matter, fer-
ric hydrate, and the porosity of a clay, and increases
with all three. As has already been stated the more
water a clay absorbs the more it has to give off in dry-
ing and the more difficult it is, especially in the case
of fine grained clays, to avoid cracking.

COLCR OF UNBURNED CLAYS.

Ferric oxide and organic matter are the two great
coloring agents of the raw clay. Organic matter gen-
erally colors a clay gray, bluish gray, or black, while
iron according to the condition of the oxide, or the
presence of carbonate, may impart a red, yellow
brown, or sometimes a gray color.

For any given amount of organic matter or ferric
oxide, the coloration will be much more intense the
more sandy the clay.

In general it may be said that, organic matter ex-

40 GENERAL DISCUSSION OF CLAYS.

cepted, the purer clays are usually light colored, while
the impure ones are yellow, red, or brown. |

Organic matter however, frequently masks the iron
coloration, and makes it often difficult
to determine the refractory nature of
the material. ‘Some clays. which burn
perfectly white may be colored black by organic
matter as in the case of the sand clay from Pegram.
Ferrous compounds not infrequently impart a gray or
bluish tint to clay, and at times the lower part of a
clay bed may be gray while the upper portion is yellow
or red, due to the oxidation of the iron contained in it.

THE MINERALOGY OF CLAYS.

Most clays are so fine grained that it is impossible
to determine the mineral constituents with the naked
eye, and their recognition even microscopically, is
sometimes a matter of diffculty. At the same time
however, there are certain minerals, which are either
present in all clays or are to be found in a great many
of them, and these will be mentioned in the order of
their abundance.

KAOLINITE.

The mineral kaolinite is looked upon as the base of
all clays, and while it is not wanting so far as we know
in any of them, nevertheless, it is not as abundant as
we have been apt to consider it, nor are the charact-
eristic properties of clay wholly due to it.

Kaolinite, whose formula is Al,O,, 2Si0,, 2H,O, or
silica 46.3 per cent., alumina 39.8 per cent., water 13.9
per cent is a white scaly minera: crystalliziug in the
monoclinic system, the crystals presenting the form
of small hexagonal plates. Its specific gravity is 2.2

MINERALOGY OF CLAYS. 41

to 2.6 and its hardness is 2 to 24. It is naturally

white in color and plastic when wet but very slightly |

so. The microscope shows the kaolinite to be collect-
ed in little bunches which can be broken apart by
grinding and thereby increasing the plasticity.*

Kaolinite is nearly infusible but a slight addition of
fusible impurities lowers its refractoriness. A mass
of kaolinite is called kaolin, and pure kaolin is practi-
cally unknown.

Many kaolins contain very minute scales of white
mica, which under the microscope are hardly distin-
guishable from kaolinite. It is not to be inferred that
kaolinite always occurs in hexagonal plates, for in
some clays scales of six sided outline are almost want-
ing.

QUARTZ,

This mineral is present in sedimentary clays most-
ly in the form of rounded grains, and sometimes in
crystals, while in residual clays the particles are most
commonly angular. It is an extremely hard mineral,
which will scratch glass and possesses a shell like or
conchoidal fracture, it is practically not attacked by
the common acids, but is affected by alkaline solu-
tions. This is one of the few mineral components of
clay which, at times, occurs in grains of sufficient size
to be recognized by the unaided eye. It may be color-
less but the surface of the grain is not ififrequently
stained by a th'n film of iron oxide. Feldspar might
be mistaken for it, but the latter will not scratch
glass.

Flint or non-crystalline silica is sometimes present
in clays. It usually has a muddy color and a con-
choidal fracture.

*G. H. Cook, Clays of New Jersey, Geological Survey, 1878.

42 GENERAL DISCUSSION OF CLAYS.

Both quartz and flint are infusible at very high
temperatures but the presence of other minerals may
serve to flux them. Quartz tends to diminish the
shrinkage of the clay, and if wanting it has to be
added during the process of manufacture. Its addi-
tion also tends to decrease the plasticity.

CALCITE.

This mineral which is carbonate of lime, effervesces
when moistened with muriatic acid, so that its pres-
ence in clay may often be detected by the addition of
this chemical. Calcite is a soft mineral and occurs in
the clay, either in the form of little rhombohedral or
powdery particles. Clays, which contain a large
amount of it in finely divided condition, are
said to be marly, and in some clay deposits
certain layers may contain a larger percent-
age of carbonate of lime than others. The

_carbonate of lime found in clays may be derived
from particles of limestone ir the clay if it is a sedi-
mentary one, or from the decomposition of limc-soda
feldspar in the case of either sedimentary or residual
deposits. Percolating water may also introduce it
into the clay.

. GYPSUM.

Gypsum or the sulphate of lime is found in clay in
the form of grains, needles, well developed crystals,
or lamellar masses. It is so much softer than calcite
that it can be scratched by the finger nail, often has a
pearly lustre, is transparent, and does not efferveyce
when acid is poured on it. In hard burned brick gyp-
sum simply acts as a flux, but in lightly burned ones

MINERALOGY OF CLAYS. 43

it gives rise to soluble sulphates which cause efflores-
cence.

MICA.

This mineral can be frequently detected by the nak-
ed eye, owing to its high lustre, even when it is present
in the form cf very minute scales. It is seldom absent
in clays and is usually found to an appreciable extent
in even the best kaolins, for on account of its scaly
nature and lightness, it remains suspended in water
for a long while and is consequently very hard to re-
move by washing; small amounts of white mica are
rarely injurious.

Mica is usually found in those clays which have been
derived from the breaking down of igneous or meta-
morphic rocks, such as granites, gneisses or schists,
and two species are recognized in clay, i. e. biotite and
muscovite. The former is a complex silicate of iron,
magnesia, and alumina, and occurs as six sided plates
or irregular sceles usually of a dark color. As it,easi-
ly decomposes with the formation of iron oxide, it is
not so apt to be found in clays as the muscovite, which
is more resistant to weathering. The muscovite is
sometimes called potash mica, although it also con-
tains a small amount of iron and magnesia; it is of
silvery white or light brown color.

Mica decreases the plasticty of clay, and tends to
make it flaky when wet, if in a finely divided condition.

White mica tends to increase the refractoriness of a
clay, and to exert very little fluxing action, even at
moderately high temperatures.

IRON OXIDE.

This, next to quartz, is perhaps the commonest min-
eral impurity of clay. It occurs as earthy grains, as

44 GENERAL DISCUSSION OF CLAYS.

metallic scales or as a superficial coating on other
mineral grains found in the clay. It dissolves quietly
in muriatic acid. Iron may also occur in the clay as
a constituent element of many silicates, and indeed
the effect which it produces may be caused not so
much by the actual amount of iron oxide which is
present, but by the condition which ‘t is in.

Tron oxide is very apt to form concretions in the
clay, and these concretions which generally have a
shell-like structure, vary in diameter, commonly from
a fraction of an inch to several inches. Siderite, the
carbonate of iron, which is also to be found in many
clays, likewise forms concretions or opaque rounded
masses, which effervesce on the addition of warm
muriatic acid. The exterior of these siderite concre-
tions is not unfrequently altered to limonite, the
brown or yellowish hydrated cxide of iron. Such con-
cretions are hard and rock-like in their nature, and
either have to be separated by screening the clay be-
fore using. or crushed by passing the clay between

rolls.
PYRITE.

This mineral is a compound of iron and sulphur,
and the grains of it are easily recognized by their
metallic lustre and their yellow color. It is a very
common constituent of many fire clays, and occurs
either in the form of small grains or concretionary
masses of yellow crystals. Its bright metallic surface
will serve to distinguish it from limonite which has a
dirty appearance.

DOLOMITE.

This is a double carbonate of lime and magnesia,
and may occur in a clay in the same form as calcite,
and the effect of it is practically the same.

METHODS OF CLAY ANALYSES. 45

METHODS EMPLOYED IN MAKING CLAY
ANALYSES.*

The following brief statement of the methods em-
ployed in making the analyses of clays for this report
has been prepared by Dr. Charles Baskervilh, by
whom the analyses were made:

Moisture—Two grams are heated in a platinum
crucible at 100° C. until they show a constant weight.
The loss is reported as moisture.

Loss on Ignition (combined water, and sometimes
organic matter, etc.)—The crucible and clay are
heated with a blast lamp until there is no further loss
in weight.

Alkalies—This same portion of clay, which has
been used for determining moisture and loss, is treat-
ed with concentrated sulphuric and hydrofluoric acids
until it is completely decomposed. The acids are
evaporated off by heating upon the sand-bath. The
cooled: crucible is washed out with boiling water to
which several drops of hydrochloric acid have been
added. The solution after being made up to about
five hundred cubic centimetres is boiled, one-half
gram ammonia oxalate added and made alkaline with
ammonium hydroxide; the boiling is continued until
but a faint odor of ammonia remains. The precipitate
is allowed to settle and is separated from the liquid
by filfering and washed three ltimes with boiling
water. The filtrate is evaporated to dryness and ignit-
ed to drive off ammonia salts. The residue is treated
with five cubic centimetres of boiling water, two or
three cubic centimetres of saturated ammonium car-
bonate solution are added and the whole is filtered

*Reprinted from Bulletin No. 18, North Carolina Geological Survey,
1897. ‘

46 GENERAL DISCUSSION OF CLAYS.

into a weighed crucible or dish. The precipitate is
washed three or four times with boiling water and the
fillrate evaporated to dryness. Five drops of sul-
phuric acid cre added to the residue, and then the cru-
cible or dish is brought to a hot heat, cooled in a des-
icator, and the alkalies are weighed as a sulphate.

To separate the alkalies, the sulphates are dissolved.
in hot water, acidified with hydrochloric acid, suffi-
cient platinum chloride added to convert both sodium
and potassum salts into double chlorides; the liquid
is evaporated to a syrup upon a water-bath, eight
per cent. alchohol added, and filtered through a Gooch
crucible or upon a tared filter paper. The precipitate
is thoroughly washed with eighty per cent. alcohol,
dried at 100° C. and weighed; the potassium oxide is
calculated from the double chloride of potassium and
platinum.

When magnesium was present to as much as one-
half of one per cent., the magnesium hydroxide was
precipitated with barium hydroxide solution and the
barium in turn removed by ammonium carbonate.
When the amount of magnesium was less than the
amount named, this portion of the ordinary process
was not regarded as necessary.

Silica—Two grams of clay are mixed with ten
grams of sodium carbonate and one-half gram of pot-
assium nitrate and brought to a calm fusion in a plati-
num crucible over the blast lamp. The melt removed
from the crucible is treated with an excess of hydro-
chloric acid and evaporated in a casserole to dryness
upon a water-bath, and heated in an air-bath at 110°
C. until all the hydrochloric acid is driven. off. Dilute
hydrochloric acid is added to the casserole now, and

the solution brought to boiling and rapidly filtered.

METHODS OF CLAY ANALYSES. 47

The silica is washed thoroughly with boiling water
and then ignited in a platinum crucible, weighed, and
moistened with concentrated sulphuric acid. Hydro-
flouoric acid is cautiously added until all the silica has
disappeared. The solution is evaporated to dryness
upon a sand-bath, ignited and weighed. The differ-
ence in weight is silica.

Tron Sesquioxide—The filtrate from the silica is
divided into equal portions. To one portion in a reduc-
ing flask is added metallic zinc and sulphuric acid.
After reduction and filtration to free the liquid from
undissolved zinc and carbon, the iron igs determined
by titration with a standard solution of potassium
permanganate.

Aluminium Oxide~-To the second portion, which
must be brought to boiling, ammonium hydroxide is
added in slight excess, the boiling continued from two
to five minuts, the precipitate allowed to settle and
then caught-upon the filter, all of the chlorides being
washed out with boiling water. The precipitate is
ignited and weighted as a mixture of aluminium oxide
and iron sesquioxide. The amount of iron sesquioxide
already found is taken from this and the remainder
reported as alumina.

*Calcium Oxide—The filtrate from the precip:tate
of iron and aluminium hydroxides is concentrated to
about two hundred cubic centimetres, and the calcium
precipitated in a hot solution by adding one gram of
ammonium oxalate. The precipitate is allowed to
settle during twelve hours, filtered and washed with
hot water, ignited and weighed as calcium oxide.
When the calcium is present in notable amounts, the
oxide is converted into the sulphate and weighed as
such.

Magnesium Oaide—The filtrate from the calcium

48 GENERAL DISCUSSION OF CLAYS.

oxalate precipitate is concentrated to about one hund-
red cubic centimetres, cooled, and the magnesium pre-
cipitated by means of hydrogen disodium phosphate
in a strongly alkaline solution, made so by adding ten
cubic centimetres of ammonium hydroxide (0.90 sp.
gr.). The magnesium ammonium phosphate, after
standing over night, is caught upon an ashless filter,
washed with water containing at least five per cent.
ammonium hydroxide, burned and weighed as mag-
nesium pyrophosphate.

The insoluble residue is determined by dige~ting
two grams of clay with twenty cubic centiments of
dilute sulphuric acid for six or eight hours on a sand-
bath, the excess of acid being finally driven off. One
cubic centimetre of concentrated hydrochloride acid
is now added and boiling water. The insoluble por-
tion is filtered off, and after being thoroughly washed
with boiling water is digested in fifteen cubic centi-
metres of boiling sodium hydroxide of ten per cent.
strenth. Twenty-five cubic centimetres of hot water
are added and the solution filtered through the same
filter paper, the residue being washed five or six times
with boiling water. The residue is now treated with
hydrochloric acid in the same manner and washed up-
on the filter paper, and free from hydrochlo«’c acid,
is burned and weighed as insoluble residue.

A portion of this is treated as the original clay for
silica, aluminium oxide and iron oxide. Another por-
tion is used for the determination of the alkalies in
the insoluble residue.

Titanic Oxide—One-half gram of clay is fused with
five grams potassium bisulphate and one gram sodium
fluoride in a spacious platinum crucible. The melt is
dissolved: in five per cent. sulphuric acid. Hydrogen
dioxide is added to an aliquot part and the tint com-

METHODS OF CLAY ANALYSES. 49

pared with that obtained from a standard of titanium
sulphate.

Sulphur (total present)—The sulphur is deter-
mined by fusing one-half gram of clay with a mixture
of sodium carbonate, five parts, and potassium nit-
rate, one part. The melt is brought into solution with
hydrochloric acid. The silica is separated by evapora-
tion, heating, resolution, and subsequent filtration.
Hydrochloric acid is added to the filtrate to at least
five per cent. and the sulphuric acid is precipitated
by adding barium chloride in sufficient excess, all solu-
tions being boiling hot. The barium sulphate is filt-
ered off and washed with hot water, burned and weigh-
ed as such.

Ferrous Oxide—is determined by fusing one-half
gram of clay with five grams sodium carbonate, the
clay being well covered with the carbonate, the top be-
ing upon the crucible. The melt is dissolved in a‘mix-
ture of dilute hydrochloric and sulphuric acids in an
atmosphere of carbon dioxide. The ferrous iron is
determined at once by titration with a standard pot-
assium permanganate solution.

The rational analysis is made from the results ob-
tained by the chemical analysis in the following way:
The alumina found in the portion insoluble in sul-
phuric acid and sodium hydroxide is multiplied by
3.51. This factor has been found to represent the
average ratio between alumina and silica in orthoclase
feldspar; therefore the product just obtained would
represent the amount of silica that would be present
in undecomposed feldspar. The sum of this silica with
the alumina, ferric oxide and alkalies equals the
“feldspathic detritus.” The difference between silica
as calculated for feldspar and the total silica in the
insoluble portion represents the “quartz” or “free

50 GENERAL DISCUSSION OF CLAYS.

sand.” The difference between that portion of the
sample insoluble in sulphuric acid and sodium
hydroxide and the total represents the “clay sub-
stance.” The method of analysis used to detrmine
the mineralogical character of the clay is called the
rational method, and when carried out in its simplest
form, determines the amount of clay substance or
kaolinite, quartz, and feldspar present ‘n the clay. If
carried out more completely, it enables us to calculate
the amount of calcite or limestone (calcium carbon-
ate)’ iron oxide and even mica in the clay.

THE RATIONAL ANALYSIS OF CLAY.

The rational analysis of clay consists in resolving
the clay into its mineralogical elements, thus giving

a clue to its physical as well as its chemical properties.
It is often utilized by manufacturers of porcelain and
other high grades of ware as a guide in the compound-
ing of their mixtures. ,

The ordinary quantitative or ultimate analysis
regards the clay as a mixture of oxide of the elements,
although they may be present in entirely different
combinations, such as silicates, carbonates, hydrates,
sulphates, etc. This condition of combination is im-
portant for it makes a difference in the behavior of
the clay. Thus for instance, if silica is present in the
form of quartz it will decrease the shrinkage and also
increase the refractoriness up to a certain point, but
if present as a component element of feldspar it serves
as a flux and also increases the plasticity somewhat.

It is not intended though that the rational analysis

RATIONAL ANALYSIS OF CLAY. 51

shall fully supplant the ultimate one for each serves
its own purpose.

The ultimate anaiysis may be used to supply in-
formation on the following points.

1. The purity of the clay, by showing the propor-
tions of silica, alumina, combined water and fluxing
impurities.

2. From the ultimate analysis we can form a gen-
eral idea regarding the refractoriness of the clay, for,
other things being equal the greater the total sum of
the fluxing impurities, the more fusible the clay.

3. The color to which the clay burns may also be
judged approximately for the greater the amount of
iron in the clay the deeper red will it burn, provided
the iron oxide is evenly distributed, and there is
not an excess of lime in the clay. If the proportion of

iron to lime is as 1; 3, then a buff product results,
provided the clay is only heated to incipient fusion or
vitrification. The above conditions will be affected
by a reducing atmosphere in burning or of sulphur in
the fire gases.

4. Clays with a large amount of combined water
sometimes exhibit a tendency to crack in burning.
This combined water would be shown in the ultimate
analysis.

5. A large excess of silica would indicate a sandy
clay.

The connection between refractoriness and chemical
composition may be illustrated by the following
analysis..

52 GENERAL DISCUSSION OF CLAYS.

The following analyses indicate this fact :
1 2 3

Per cent. Per cent. Per cent
SlOgiwas | saaeta wea wees 47.20 69.50 54.90
BlsOgiea Ganaawla cotenens .--. 86.50 13.00 18.03
TWegOs. eaiwrasc Guede Sohoemase 2.56 -6.40 6.03
CAO 5 sisiy Geiedians: sores udstelens eieiee > TES 25 2.88
Mg Owcews Bee atie pilex aes ERS tt: « 1.10
AMKANOS! ces veces eis tr. 3.40
BeGiss aseesd saecias wees 18.35 6.70 6.90
Moisture ...... ...... otk -50 3.40 3.17
Total AUXES! .. 6. see, eae 2.56 6.65 13.41
DEG. F. DEG. F. DEG. F.
Viscosity or fusion point. Above 2700 2300 1900

1. Chalk Bluff, Marion Co., Ala., U. S. Geol. Surv. 18th Ann. Rep., Part V-
(continued), p. 1128.

2. Fernbank, Lamar Co., Ala. Ibid.
3. Norborne, Mo. Mo. Geol. Surv., XI. Ann. Rep.

This is practically the full extent to which the ulti-
mate analysis can be used; and there still remain
to be explained a number of physical facts concerning
any clay which happens to be under consideration.

It frequently happens that two clays approach each
other quite closely in their ultimate composition, and
still exhibit an entirely different behavior when burn-
ed. The explanation which most quickly suggests it-
self is, that the elements present in the two clays are
differently combined. Some method of resolving the
clay into its mineral components, so as to indicate the
condition in which the elements are present is there-
fore practically needed.

As kaolinite results from the decomposition of feld-
spar, the kaolin is quite sure to contain some unde-
composed feldspar, and also some quartz, and (in
smaller amounts) mica, since the two latter minerals
are common associates of the feldspar.

If, now, we know the amount of feldspar, quartz
and kaolinite or clay-substance in the kaolin, and: the
effect of these individual minerals, we can form a far

RATIONAL ANALYSIS OF CLAY. 53

better opinion of the probable behavior of the clay in
burning.

When mica is present, it ‘s dissolved out with the
kaolinite and reckoned in as clay-substance, but it is
rarely present in large amounts, and may perhaps
alter the character of the clay-substance but little, for
finely ground white mica possesses plasticity, and can
be formed and dried without cracking. It is more re-
fractory than feldspar, and holds its form up to
1400° C.*

In the following table are given the ultimate and
rational analyses of a number of kaolins, which show
how a constancy of ultimate composition may be ac-
companied by variations in the rational analysis:

*@. Vogi, Chem. News, 1890, p. 315.

GENERAL DISCUSSION OF CLAYS.

54

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RATIONAL ANALYSIS OF CLAY. 55

From this table a number of interesting conclusions
may be drawn. Columns 1 and 2 represent iwo clays
which agree very closely in their ultimate composi-
tion; but in the rational analysis there is a difference
of 6 per cent. in the clay-substance, 12 per cent. in
quartz, and nearly 19 per cent. in the feldspar. Nos.
3 and 5 and 10 and 12 also illustrate this point.

In Nos. 6 and 7, one a German, and the other a
North Carolina kaolin, the ultimate analyses are very
closely alike, and the rational analyses also agree very
well. This is frequently the case when the clay-sub-
stance is very high, between 96 and 100 per cent., as in
Nos. 9 and 11.

A third case would be presented if the rational an-
alyses agreed, but the ultimates did not. Such in-
stances, however, seem to be much less common.

The practical value of the rational analysis: bears
chiefly upon those branches of the clay-working in-
dustry, such as manufacture of porcelain, white earth-
enware, fire-brick and glasspots, which use materials
with comparatively few fusible impurities (iron, lime,
magnesia).

There is much concerning clays which sitll remains
unexplained, but it seems probable that, other things
being equal, two clays having the same rational com-
position will behave alike.

We can illustrate this point by the follownig tests
made on washed kaolins from the vicinity of Senne-
witz, near Halle, Germany. I[*rom the figures given
below, it will be noticed that in the case of Nos. 1 and
2 there is a close agreement in the shrinkage, which
amounted to about 10 per cent. when the clay was
heated up to the temperature of a hard-porceclain
kiln. In Nos. 3 and 4 the shrinkage is very nearly the
same, but greater than in Nos. 1 and 2, because the

56 GENERAL DISCUSSION OF CLAYS.

rational composition has changed, there being a mark-
ed increase in the amount of feldspar.

If there hed been much difference in the size of the
clay-particles of Nos. 3 and 4 or Nos. 1 and 2, the
shrinkage in each case would probably have been dif-
ferent. :

TABLE II.—Rational Analysis and Shrinkage of Clays.

Shrinkage in
Hard Porcelain
Feldspar. Quartz. Clay-Substance. Fe.O3 Fire

Per cent. Per cent. Per cent. Per cent. Per cent
* 1.59 33.86 64.55 0.75 10.20
1.21 338.39 65.40 0.73 10.10
8.64 31.69 59.68 0.30 12.90
8.25 35.15 56.60 0.30 12.00

The degree of fineness of the clay-particles, and per-
haps their shape also, probably exert more influence
on the shrinkage than has been imagined, but just how
far this makes itself felt is still undetermined.

AS an illustration of the practical use of the rational
analysis we may take the following:

Suppose that we are using for the manufacture of
porcelain or fire-brick a kaolin which has 67.82 per
cent. of clay-substance, 30.93 of quartz, and 1.25 of
feldspar, and that to 100 parts of this is added 50
parts of feldspar. This would give us a mixture of
45.21 per cent. of clay substance, 20.62 of quartz, and
34.17 of feldspar.

If now for the clay we had been using, we substitu-
ted one with 66.33 per cent. of clay-substance, 15.61
of quartz, and 18.91 of feldspar, and made no other
changes, the mixture would then contain 44.22 per
cent. of clay-substance, 10.41 of quartz and 45. 98 of
feldspar.

This last mixture shows such an increase in feldspar
that it must give much greater shrinkage and fusibil-

CLASSIFICATION OF CLAYS. 57

ity; but knowing the rational analysis of the new
clay, it would be easy to add quartz or feldspar so as
to bring the mixture back.to its normal composition.

The application of the method of rational analysis
te impure clays is not quite as satisfactory, but at the
same time not as necessary. In the treatment, the
iron, if present as oxide, and lime cr magnesia, if car-
banotes, are dissolved out with the clay-substauce.
The silicate minerals are grouped with the feldspar,
and the clay thus becomes divided into clay-substance
(kaolinite, ferric oxide, lime and magnesia carbon-
ates), feldspar or feldspathic detritus; and quartz.
If the percentage of ferric oxide and carbonates is
high, it is necessary to determine them separately in
the ultimate analysis.

In making a rational analysis, the clay is treated
with strong sulphuric acid, which decomposes the kao-
lin into sulphate of alumina and hydrous silica. The
former is soluble in water, while the latter is removed
with caustic soda, and we get an insoluble residue con-
sisting of quartz and feldspar. In this residue the
alumina is determined and the feldspar calculated.

Another way of conducting the rational analysis,
and one which is chiefly applicable when the clay con-
tains other minerals besides the kaolin, quartz and
feldspar, such as carbonate of lime, ferric oxide, or
mica, consists in analysing the insoluble residue and
calculating the mineral percentages from this.

THE CLASSIFICATION OF CLAYS.

As it is possible to find every gradation from the
purest to the most impure clays any classification that
is attempted, will necessarily be more or less unsatis-
factory. It is of course possible primarily to make

58 GENERAL DISCUSSION OF CLAYS.

two great divisons i. e. residual and sedimentary, and
to these might perhaps be added a third class of clays,
namely, those formed by chemical precipitation. Un-
der each of the first two classes, it would be possible
again to find every gradation from pure to impure.

It is not possible to make any classification based
upon the practical applications of the materials, for
some clays are used for as many as four to five dif-
ferent purposes, and it is probable that some classi-
fication which simply recognizes four or five important
groups is probably the most satisfactory and the least
confusing. Hill makes the following divisions :*

China clays.

Plastic, ball, pottery clays.

Brick clays.

Refractory or fire clays.

He furthermore makes duper table based on the
origin of the clay as found in the United States:

I—WHITE BURNING CLAYS.

Rock or residual kaolin.
Indianite or Indiana kaolin.
Florida or sedimentary kaolins.
White burning plastic clays.

oN

II—COLOR BURNING CLAYS.
Mixed clavs—
Brick clays, (Siliceous).
Marly clays, (Calcareous).
Pink clays, (Ferruginous).
Cement clays, (Silico-calcareous).
Alum clays.
Altered clays (shale and slate).

Gr wom pom

*U.S. Geol. Survey, Mineral Resources, 1893.

‘MINING AND PREPARATION OF CLAYS. 59

A classification which has been made by Seger, the
great German Ceramic Chemist, gives:

1. Yellow burning, containing lime and iron.

2. Red burning, non-aluminous, ferruginous clays,
which are free from lime.

3. White and yellow burning. These clays are low
both in lime and iron.

4. White burning, low in iron and high in alumina.

THE MINING AND PREPARATION OF CLAYS.

RPOSPECTING FOR CLAYS.

Clay deposits are best seen in those regions where
rivers and brooks have cut gullies and ravines, the clay
showing on the sides of the cut. In such locations the
thickness of the deposit and variation in its character
vertically are well shown. Similar sections are to be
loooked for along railroads. As the beds are apt to
wash down it is necessary to clean the surface of the
cut before taking any sample for testing, and even
then great care must be observed to insure the sample
being an average one.

Apart from cuts the presence of clay can often be
determined by the character of the vegetation, the na-
ture of the soil, or upturned tree roots.

The outcropping of clay in a ravine should not be
depended on alone, but in addition borings should be
made to determined the depth and extetnt-of the de-
posit, and persistance of the different layers if there
is a variation in them.

Shale often forms cliffs or steep slopes, at the base
of which there may be a talus of partly weathered
fragments and soft clay; in fact the outcrop of a shale
deposit may be covered by the clay into which it has

60 GENERAL DISCUSSION OF CLAYS.

slaked under the influence of weathering. In some
localities this mellowed outcrop may be only a few
feet thick, but in many it is of sufficient volume to sup-
ply a small brick yard, without the necessity of at-
tacking the fresh shale beneath.

MINING OF CLAYS?*:

Clays, when soft and plastic, are mostly dug with
pick and shovel, loaded on wheel-barrows, carts or cars
and hauled to the works. If the deposit is broad and
shallow the clay is usually dug at any convenient
point; often any overlying sand or other useless ma-
terial has been first removed and used for filling in or.
some other purpose.

If the bank is located on the hillside, and has con-
siderable height, it is worked out in broad steps, the
object of this being to prevent the bank from sliding
in wet weather.

When the bank is near the works, wheel-barrows or
carts can be used to haul the clay, but far distances,
over 600 feet, it pays to lay tracks and use cars, haul--
ed either by horse or steam power.

Underground methods of mining are only used in
case the amount of overlying material is very great.
It is chiefly used for shale deposits.

Steam shovels are employed for sandy clays or soft
shales at some localities in the Uuited States, but
most shales are mined by blasting, and the fragments
thus ioosened are sent to the works.

Where the clay is rough, and the face of the bank
12 or 15 feet high, a plan often followed is to under-
mine it by picking at the base, and then inserting
large wooden wedges at the top. This brings down

,
*This does not include the mining of kaolin, which is treated separately.

MINING AND PREPARATION OF CLAYS. 61

a large mass at once, the fall serving to break it up.

While effective, this method is often attended with
danger.

MINING OF KAOLIN.

Kaolin is usually sufficiently soft in nature. to be
mined by means of the pick and shovel. In some por-
tions of the beds near Valley Head streaks of halloy-
site are found in the clay, which are quite hard, but
they are of such a limited extent as not to cause much
' extra trouble. If the deposit is deep, narrow, or in-
terbedded with other formations which are too thick
to be removed by stripping, or if again the kaolin does
not run regular in its composition, it is often advisable
to follow the better portions of the bed, or the narrow
vein if it is such, by means of shaft, levels, or slopes.
These sometimes have to be timbered, at other times,
as at Valley Head, they do not.

In the case of deposits which are large and broad,
it is most economical to operate them as quarry work-
ings or open pits, digging out the material and loading
it on the cars or wheel-barrows which convey it to
the washing plant. If a pit is large and broad the
sides, instead of being dug out vertically, should be
left in benches to prevent the washing down of the
bank.

In North Carolina, where most of the kaolin depo-
sits are vein formations whose depth is comparatively
great as compared with their width, the method ad-
opted is to sink a circular pit in the kaolin about 25
feet in diameter. As the pit proceeds in depth it is
lined with crib work of wood, and this lining is ex-
tended to the full depth of the pit, which varies from
50 to 100 or even 120 feet. When the bottom of the

62 GENERAL DISCUSSION OF CLAYS.

kaolin has been reached the filling in of the pit is
begun, the crib work removed from the bottom up-
ward as the filling proceeds. If there is any overbur-
den this is used for filling in the pit, and as soon as pit
is worked out a new one can be sunk in the same
manner right next to it. In this way the whole vein is
worked out, and if the deposit is large, several pits
may be sunk at the same time to increase the output
of the mine.*

Hydraulic mining has been tried with some success
in some very sandy loose-grained kaolins, but it would
not work in any of the deposits in Alabama, which the
writer has thus far examined. The method to state it
briefly, consists in washing the clay down into the
bottom of the pit whence it is sucked up by means of
a pump and discharged into washing trough from the
conveying pipe, it being sometimes necessary to have
a scraper to stir or loosen up the clay in order to per-
mit its being drawn up more easily. This is a cheap
and rapid methed where it can be employed, but most
kaolins are too dense and not sandy enough to allow
of its being used.

THE WASHING OF KAOLINS.

As has already been stated, most kaolins have to be
washed before shipment, and one of two methods may
be employed, i. e. washing in tanks or troughing.
With the first method or that of washing in tanks, the
kaolin is thrown into large circular tubs filled with
water, in which it is stirred up by means of revolving
arms and the clay lumps thereby disintegrated. By
this treatment the fine kaolinite particles as well as
very fine grains of mica, feldspar, and quartz remain

*H. Riese, Clay Deposits and Clay Industry in North Carol'na Bulletfn No. 13,
N. C. Geol. Surv., p. 54.

MINING AND PREPARATION OF CLAYS. 63

suspended in the liquid while the coarser grains set-
tle on the bottom of the tank. The water with the
suspended clay is then drawn off to the settling tanks.

A modification of this consists in the use of a large
cylinder closed at both ends and set in a horizontal
position; through this cylinder passes an axis with
iron arms, the revolution of the latter serving to break
up the clay, which is discharged through a hopper at
the top. A current of water passes through the cylinder
and carries the fine clay particles with it while the
coarse ones are left behind in the machine. The speed
of the current has to be regulated by experiment,
for if too much water is used coarse material
will be washed out of the cylinder, and
conversely, if the current is too slow the clay
will not yield a _ sufficient percentage of
washed product. One objection to this apparatus is
that it has to be stopped from time to time to remove
the coarse sand from the machine.

The method most commonly used at the present
day for washing kaolin, is by troughing and its gen-
eral detail is as follows:

As the kaolin comes from the mine it is generally
discharged into a log washer, which consists of a semi-
cylindrical trough in which there revolves a horizont-
al axis, bearing short arms. The action of these arms
breaks up the kaolin more or less thoroughly, depend-
ing on its density, and facilitates the subse%uent wash-
ing. The stream of water directed into the log washer
sweeps the kaolin and most of the sand into the wash-
ing trough, which is about 15 inches wide and 12
inches deep. It may be wider and deeper if the kaolin
is very sandy; in fact it should be. The troughing is

about 700 feet long, and to utilize the space thorough-
ly, it is broken up into sections, 50 feet to each is a

64 GENERAL DISCUSSION OF CLAYS.

good length, these being arranged paralleled, and
connected at the ends, so that the water, with sus-
pended clay, follows a zigzag course.

This troughing has a slight pitch which is common-
ly about one inch in twenty feet, but the amount of
pitch depends upon the kaolin, and whether the sand
which it contains is fine or coarse. If the kaolin is
very fine, and settles slowly, the pitch need not be so
great and vice versa. A large quantity of very coarse
sand in the kaolin is a nuisance as it clogs up the log
washer, and upper end of the trough more quickly and
causes so much more labor to keep them clean. As it
is, considerable sand settles there, and, to keep the
trough clear, sand wheels are used. These are wooden
wheels bearing a number of iron scoops on their peri-
phery, as the wheels revolve these scoops catch up a
portion of the sand which has settled in the trough,
and as each scoop reaches the upper limit of its turn
on the wheel, it, by its inverted position, drops the
sand: outside of the trough. These sand wheels are an
aid, but it is often necessary, in addition, to keep a
man shoveling the sand from the trough.

If the sand is finer it is not dropped so quickly, but
is distributed more evenly along the trough, and does
not clog it up so fast.

The zigzag arrangement of the troughing has been
objected to by some, as it produces irregularities in
the current causing the sand to bank up in the corners
at the bends, and also at certain points along the sides
of the troughing.* :

The effect of this is to narrow the channel, and con-
sequently to increase the velocity of the current, there-
by causing the fine sand to be carried still further to-

*E. Hotop, Thonindustrie Zeitung, 1833.

MINING AND PREPARATION OF CLAYS. 65

ward the settling tank. This difficulty, which is not
often a serious one, has been obviated either by havy-
ing the troughing longer or by allowing the water and
suspended clay, as they come from the log washer, to
pass through a section of straight trough, and from
this into another one, of the same depth but five or
six times the width, and divided by several longitu-
dinal partitions. The water and the clay then pass
into a third section, twice as wide as the second, and
divided by twice the number of longitudinal divisions.

By this means the water moves only in a straight
course, but as it is being continually spread out over
a wider space it flows with an ever decreasing velocity.

By the time the water has reached the end of the
troughing, nearly all of the coarse grains have been
dropped and the water is ready to be led into the set-
tling vats, but as a further and necessary precaution
it is discharged on to a screen of one hundred meshes
to the linear inch, the object of this being to remove
any coarse particles that might possibly remain, and
also to eliminate sticks and other bits of floating dirt
that are sure to find their way in.

Two kinds of screens can be used, (1) stationary,
and (2) revolving.

The stationary screen is simply a frame with a cop:
per cloth and set at a slight angle. The water and sus-
pended kaolin fall on the screen, and pass through.
A slight improvement is to have two or three screens
which overlap each other so that whatever does not
get through the first will fall on the second. If the
vegetable matter and sticks are allowed to accumu-
late, they stop up the screen, and prevent the kaolin
from running through, consequently the stationary
screens have to be closely watched.

The revolving screens are far better for they are

66 GENERAL DISCUSSION OF CLAYS.

self cleaning. Such sereens are barrel shaped, and the
water, with the kaolin in suspension, is discharged
into the interior and passes outward through the screen
cloth. As the screen revolves, the dirt caught is car-
ried upwards and finally drops; but instead of falling
down upon the other side of the screen, it falls upon a
board, which diverts it out upon the ground.

The settling tanks, into which the kaolin and the
water are discharged, may. be and often are about
eight feet wide by four feet deep, and fifty or more
feet long. As soon as one is filled the water is diverted
into another.

The larger a tank, the toes will it iake to fill it,
and allow the kaolin to settle, and delays due to this
cause them to be expensive, especially when the market
takesthe output of washed kaolin as soon as it is ready.

Small tanks have the advantage of permitting the
slip to dry more quickly, especially when the layer of
clay is not very thick, and furthermore a small pit
also takes less time to fill and empty, but one dis-
advantage urged against a number of small tanks is
that a thorougly average product is not obtained ow-
ing to the thin layer of settlings and the small amount
in each. In addition to this a series of small tanks
requires considerable room.

The advantages claimed for large tanks are that the
clay can be discharged into any one for a considrable
period, and, if the clay deposit varies in character, the
different grades get into one tank and a better average
is thereby obtained.

If the kaolin settles too slowly, alum is sometimes
added to the water to hasten the deposition. When
the kaolin is settled, most of the clear water is drawn
off, and the cream like mass of kaolin and water in the

MINING AND PREPARATION OF CLAYS. 67

bottom of the vat is drawn off by slip pumps and for-
ced by these into the presses. :

The presses consist simply of flat iron or wooden
frames between which are fiat canvas bags. These
bags are connected by nipples with a supply tube from
the slip pumps, and by means of the pressure from the
pumps nearly all of the water is forced out of the
kaolin and through the canvass.

When all of the water possible, is squeezed out the
press is opened and the sheets of semi-dry kaolin are
taken out. It is then dried either on racks in the open .
air or in a heated room.

As for every ton of crude kaolin usually only about
two-fitths o1 oue-fourth of a ton of washed kaolin is
obtained, it is desirable to have the washing plant at
the mines, for it avoids the hauling of 60 to
70 per cent. of useless sand which has to be washed
out before the kaolin can be used or even placed on.
the market.

II.

GEOLOGICAL RELATIONS OF THE
| CLAYS OF ALABAMA,

By EUGENE A. SMITH, PH. D.

The basis of all clays is kaolinite, the hydrated
silicate of alumina resulting from the chemical decom-
position of alumina bearing minerals which occur as
essential constituents of igneous rocks. In this de-
composition, as Dr. Ries has shown, the soluble con-
stituents are leached out while the kaolinite remains
behind as an insoluble residuum, more or less mixed
with the other -nsoluble matters of the original
minerals.

In this form the clay might be called a chemical
clay, since it is the direct result of a chemical decom-
position, having undergone no further modification
by being taken up, transported and redeposited.

There is another form of residual clay which may
be distinguished from the above, and that is the clay
resulting from the decomposition of impure limestone.
Naturally this variety is usually less free from foreign
matters than the.otker.

These residual clays taken up and redeposited by
running waters are incorporated in the stratified de-
posits of any later age.

The clay deposits of the different geological form-
nations of Alabama have each its well marked pecu-
liarities, and the geological formations are clearly de-

70 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

fined, so that an account of the geological relations of
these clays becomes a guide at once to the several va-
rieties, and to their geographical distribution.

ARCHAEAN AND ALGONKIAN.

These two formations include in Alabama all the
crystalline rocks of both igneous and sedimentary
origin. It is generally acknowledged that kaolinite,
which is the basis of all clays, has its origin in the de-
composition of the minerals composing the igneous
rocks, the chief kaolinite producing mineral being
feldspar. It is. therefore, in the area of our crystalline
or metamorphic rocks that we are to look for the origi-
nal deposits of kaolinite. More especially, it is the
granites, the pegmatites or graphic granites, that occur
the largest proportion of feldspar, and consequently
yield the largest proportion of kaolinite, and of the
granites, thepegmatites or graphic granites, occurring
in veins which traverse the other crystalline rock, are
by far the most important in this respect.

The clays occurring in this form have been spoken
of by Dr. Ries as vein clays, and they are, as a rule,
very slightly plastic, for the reason that they have not
been subjected to the comminuting processes neces-
sary to develop the highest degree of plasticity.

A belt of mica schists with frequent veins of peg-
matite, extends from Cleburne county and adjacent
parts of Randolph, through Clay and Coosa into
Chilton county, and in numerous places, the decay of
the granite veins has given rise to the formation of
deposits olf kaolinite. The other two constituents of
these granites, viz., quartz and mica, occur like the
feldspars in large masses, and thus the places which
produce mica in large sheets are at the same time the

ARCHAEAN AND ALGONKIAN. 71

places where the kaolinite is to be found. Below a
certain depth from the surface the feldspar of these
granitic veins has escaped the action of the atmos-
phere, and is in its original form, while nearer the
surface it has generally been converted into kaolinite.
It is evident that in all these primary or original de-
posits the ‘kaolinites mixed with the other and less
destructible constituents of tthe granite, viz., the
quartz and the mica, and by consequence all ‘the
kaolinite from such original deposits must be washed
to free it from these substances. When ithe granite
or granitic rock contains comparatively little of iron-
bearing minerals the resulting kaolinite will be cor-
respondingly free from iron stain and of pure white
color, and thus suitable for the manufacture of the
finer grades of stone ware or china.

All the important deposits of this kind are, at the
present time, at a distance from any railroad, and
none of them have been developed in a commercial
way. We have at hand very few analyses and itests
made of these kaolinites. A material of this kind
from near Louina in Randolph county was analyzed
many years ago by Dr. Mallett for Prof. Tuomey,
with the followine result:

Analysis of Kaolinite from Louina, Randolph Co.

GiICA ooo... . eee eecesvescensecccenecesseescoteenenenscoesennes cessessns ueamanensseeeneer seseseeeeees 37, 29
ALUMINA ..... cece ceeceteteseetsnennecen coer dude dudes ueavenenaarcnasnnaesasadesivaestetoeeee DnB
Ferric Oxide. * ewes zi ..trace
Potash, Lime and Magnesia... , 0.42
Water ...secee : 15, 09

Undecomposed “Mineral .. dea 14, 28

Prof. Tuomey remarks upon the absence of iron in
this kaolinite as most favorable to its use in making
fine porcelain ware, and he predicts that when Ran-
dolph county has communication by railroad with the

72 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

outside world, the occurrence of porcelain clay in the
county will become a matter of economic importance.

These pegmatite veins with their mica and kaoli-
nite, are very numerous in the upper half of Randolph
county, and also in the adjacent parts of Cleburne and
Clay, and test pits have been sunk in hundreds of
places to show up both the kaolinite and the mica. Dr.
Caldwell of the Elyton Land Company, had this kao-
linite- thoroughly tested both as to its suitability for
the manufacture of porcelain ware and as to its re-
fractory character. The pottery ware made from it
came in competition with the best pottery wares in
America and took a prize at the Art Institute Fair
in Philadelphia, in December, 1890. Brick made from
it also was subjected to the highest temperature of
the furance and was declared practically infusible.
These deposits lie near Milne1, Pinetucky, Micaville,
in Randolph, and near Stone Hill, Mr. Jas. Denman’s
and other places in Cleburne. The same belt extends
southwestward through Clay and Coosa into Chilton,
and has been tested at various places along this line.

In this region of the crystalline rocks, one may
everywhere observe the gradual transition from the
solid rock through decayed schists into complete soil,
which is generally a clayey loam, more or less stain-
ed wih iron. A reddish clay is thus seen to be a
part of the residual matters left by the general decay
of the rocks of this section, but this clay is, as a rule,
so much mixed with quartz, mica, fragments of un-
decomposed rock, that it can serve very seldom for
anything more than material for the manufacture
of building brick. Residual clays of this character
are of universal occurrence throughout |the region of
our crystalline rocks.

It is not difficult to understand how under certain

CAMBRIAN AND SILURIAN FORMATIONS. 73

conditions, the finer portions of these residual clays
may be taken in suspension ‘in running waters and
redeposited at greater or less distances from their
place of origin in depressions, or along slopes. In
this way are often formed secondary deposits of
pretty fair plastic clays, sometimes mixed with sand
in proportion to serve well as material for good build-
ing brick. An illustration of this may be cited near
Wedowee in Randolph county, and there are many
instances where the residual clays of the country as
well as these redeposited masses are utilized both for
the manufacture of buildings brick of excellent
quality, and for pottery purposes.

CAMBRIAN AND SILURIAN FORMATIONS.

‘In these formations, the clay deposits are either
the residual clays left from the decomposition gen-
erally of the grea't limestone formations of the Cam-
brian and Silurian, or concentrations of these resi-
dual clays by redeposition in sink ‘holes, ponds, and
depressions; or the accumulation through sediment-
ary action ,in the depressions of these later forma-
tions, of tthe chemical or vein clays of the Archaean.

The two great limestones, above mentioned, are
rarely pure but are mixed with chert or other form
of siliceous matters, with iron, and with clay. Upon
their decay under the action of tthe atmospheric
agencies, these insoluble matters are left in the form
generally of reddish loam or clay capped with cherty
fragments, and impregnated with iron.

Such residual clays are extensively used in all our
valley regions for the manufacture of ordinary build-
ing brick, for which they are very well adapited, the

74. GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

brick being very durable, but not very sightly, since
they are likely to be spotted where the clay contains
more iron than the average. Occasionally, however,
we find as result of subsequent rearrangement by
leaching, concretionary action, or the like, these resi-’
dual matters differentiated from each other in a most
remarkable way, so that beds of nearly pure white
clay lie alongside of beds of brown iron ore, itself
remarkably free from either clay or chert. The most
notable of such instances is at Rock Run where the
bed of white kaolin, analysis of which is given in the
body of this report, No. A. S., forms one of the walls
of a bank of limonite which has for years furnished
ore to the furance. In close juxtaposition to the ore -
and kaolin, here mentioned, is one of the beds of
bauxite for which this region is well known. Kaolin
beds of this residual nature are known in many other
parts of the State, resting upon the Cambrian and
Silurian limestones. Near Jacksonville, in Calhoun
county, at Tampa in the same county, and in numer-
ous other localities of similar nature, are limited
beds of kaolin, none of which, however, have as yet
been developed or worked.

The following clays described below may be assign-
ed to these formations; the china clays, No. 190, from
near Gadsen and No. 205 from Kymulga; the fire
clays, No. 191 from Peaceburg in Calhoun county and
No. 127 from Oxanna in the same county; the stone-
ware clays, No. 204 from Blount county and No. 192
from near Rock Run.

In most of ‘tthe large limonite banks of the valley
regions, these deposits of pure clay occur, usually
known as clay horses, some of them are undoubtedly
of sufficient extent to be of commercial value. Many

«

CAMBRIAN AND SILURIAN FORMATIONS. 75

references to these may be found in the Report on the
Valley Regions. |

While none of these clay deposits have as yet found
a market, it may be well for the sake of completeness
to give a few details:concerning such as have been
recorded. The references to the pages of the report
on the Valley Regions, Part II, are also added.

In connection with beds of limonite in 8. 31, T. 24,
R. 11 E., in Bibb county, mention is made of the fact
that the ore lies imbedded in clay of red or yellowish
red color, with streaks of a white clay (p. 495.)

In Talladega county, in the flatwoods, lying along
the line of the Columbus & Western Railroad, in the
southeast corner of 8. 2, T. 21, R. 3 E., a white plastic
clay which is said to have been penetrated to a depth
of 35 feet, is reported te have been struck in a well.
(p. 606.) In the same county in 8. 19, T. 19, R.5 E.,
in the Charlton limonite bank there is a large “horse”
of white clay, extensive deposits of white clay are
noticed in connection with other limonite banks in the
immediate vicinity. (p. 616.)

In Calhoun county, in T. 15, R. 8 E., and in Sec-
tions 21 and 23, there are many diggings in beds of
limonite, and in most of them are “horses” of white
clay, (p. 702). Again in T. 14, R. 8 E., in the same
county, near Tampa, on land belonging to A. H.
Tullis, Section 6, in the red residual clays derived
from the disintegration of the limestones of the
county, along with barite and limonite in pockets, are
found some deposits of kaolin of white color and
considerable thickness, up to 10 _ feet. In
Section 5 of same township and range, the kaolin is
exposedd in a cut of the East and West Alabama

Railroad where it is 10 feet thick. (p. 715.)

.

76 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

In Cherokee county, to tthe northward of the line
of the Southern Railroad in Sections 1 and 2 of T. 12,
R. 11, E., there are many banks of limonite which
have been extensively worked, and in some of
them beds or “horses” of white clay have
been exposed. One of these in the Clay limonite
bank, in Section 2, Ithe clay deposit is of great extent
and several car loads have been taken from it and
shipped to Chattanooga for manufacturing into fire
brick. A similar white clay occurs in the Hickory
Tree bank in Section 1, (p. 759.) The occurrence of
the clay in the Dyke limonite bank, near Rock Run,
is described on page 777. This is ithe kaolin whose
analysis is given below under the number A. 8. In
the Washer bauxite band in 8. 35, T. 12, R. 11 E.,
near Rock Run, and in the Warwhoop and other
bauxite banks of the same vicinity, white clay
and halloysite are of common occurrence. Some
of these clays should be utilized.

Some details concerning ithem are to be found in
the Valley Regions report, pages 780 to 789.

In the limonite banks to the eastward of Tecumseh
furance in the same county, in T. 12, R. 12, E., clay
“horses” are everywhere found separating the pock-
ets of limonite, pages 792 and 793.

Accumulations of good plastic clay, which have
evidently been deposited in the depressions of the

limestone or in ponds, are not uncommon in the area
of the great limestone formations. One such near
Oxford in Calhoun county, is utilized by the Dixie
Tile and Pottery Company. Analysis and physical
tests of this clay are given in the body of this report.

Of less purity on account of mixtures of sand, etc.,
similar deposits are numerous, and utilized in
places, as, for example, the brick clay at DeArman-
ville in the Choccolocco valley.

SUBCARBONIFEROUS FORMATIONS. 77

SUB-CARBONIFEROUS FORMATION.

In the Sub-carboniferous formation of Wills’ Val-
ley is found the best known deposit of pure white
clay of this section.

This clay occurs chiefly in the lower strata of the
formation, generally very close above the Devonian
Black Shale. The deposits which have, up to the pre-
sent time, been pretty well proven, are to be found in
the upper or northeastern end of Wills’ Valley, near
the Georgia line, and on both sides of the valley. The
most important of them, however, occur on the east-
ern side of the valley. They have been described
somewhat in detail by McCalley in Part II of his Val-
ley Regions report, pages 175 to 182, from which the
following details are compiled:

The Red Mountain ridges, made up of the strata
of the Clinton, Devonian (Black Shale), and Sub-
carboniferous formations, occur here as elsewhere
in the State, on both sides of the valley. The ridge
on the western side is, in general, lower and less con-
tinuous than that on the eastern side. The clay
occurs in-the lower strata of the Sub-carboniferous,
not far above the Black Shale, and it has been “pro-
spected” and found to be present in the ridges on
both sides of the valley for some ten or twelve miles
from the State line southward.

In the northwest corner of 8. 3, T. 6, R. 9 E., on the
west side of the valley, a test pit exposes the following
section:

Section on west side of Wil’s' Valley, DeKalb Co.
Chert ledge weathered into a sandy rock of yellow color 8 to 12 inches.

Strata hidden by CeDTIs............. ceeseeeeeteetteet see eeeceeeeenneenees 2to 3 feet.
White clay, without an in places like halloysite........... 3 feet
Bluish colored Clay .....c.cccceseeneeseeeeeeees 3 feet,
Strata not exposed .. sddee cen

Devonian Black Shale................-

78 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.
4

The white clay occurrs in many places in this
vicinity, and is called chalk by the pedple.

On the eastern side of the valley, the Red Mourtain
ridge, as stated above, is more prominent and con-
tinuous than on the west. Near the State line, about
Eureka station and thence southwestward for a
couple of miles, the clays have been tested and in
many places worked. They have a thickness aggre-
gating about 40 feet, but are said to thicken up oc-
casionally to 180 to 200 feet, of which as much as 60
feet is a fine white clay suitable for the manufactory
of stone ware. Some of the clay is shipped from here
to the potteries at Trenton N. J., and some of it goes
to Chattanooga, Tenn. The Franklin (Ohio) Com-
pany Mines are situated in the northern corner of
8. 34, T. 4, R.10 E. The clay is won by surface dig-
gings, slopes, and tunnels, according to locality.

The following section is obtained along the wagon
road through the surface: diggings and will give a
fairly correct idea of the occurrence.

Section at Franklixn Company’s Mines, DeKalb Co.
Alternations of chert layers, 4 to 18 inches thick, with fine

sharp siliceous powder of white and yellow color............... 12 feet.
Chert of light yellow color, interlaminated with thin streaks of

clay .... 4... ae ..12 feet.
Clay, mostly of yellow ‘color, ‘but with s seams of white lays ..10 feet.
Alternations of chert in layers of 2 to 8 inches thickness with

clay seams 18 inches in thickness... re i « 4 feet.

Alternations of chert in layers 2 to 6 inehes thick with white
clay in irregular seams 6 to 12 inches thick... 0 w..... eee
Clay, very gritty, of white color and chalky appearance. . an
Clay and shale, the ae white and dite the shale green .........
Devonian Black Sha‘e .. bab eegpabeslisiamlecdgasiere re Resed Soule

In these mines in the upper twenty feet the clay is
more siliceous than in the lower twenty feet. The
siliceous clay is better suited for making fire brick,
while the plastic clay is a potter’s clay, command-
ing a good price. The chert which is interstratified

SUBCARBONIFEROUS FORMATIONS. 79

with the clay is also of value in the manufacture of
stoneware. :

In the N. E. 4 of the S. E. 4 of 8. 4, T. 5, R. 10 E.
are the Montague Clay Mines, worked by a tunnel on
the southeastern side of the ridge. The clay is about
thirty feet in thickness, some of it having a brown col-
oration, due to organic matter. It is quite uniform
in composition for a distance for at least a mile in a
northeast and southwest direction, is quite free from
stains of iron but perhaps less plastic than the clay
from some of the other localities. near by. Most of
the clay here mined goes to Chattanooga for the man-
ufacture of fire brick. Two analyses of the clay
from these mines are given by Dr. Ries under the
numbers 116 and 117 and they are classed by him as

fire clays.

‘Further southwest, along the ridge, we find other
occurrences of the clay as in the S. W. # of the N. W.}
of S. 12, T. 6, R. 9 E., where there is an old open-
ing on a clay bed, which shows some four feet of clay.
Still further southwestward in the N. W. } of the
S. E. 4 of S. 15, T. 6. R. 9 E., there are numerous sur-
face diggings, and tunnels in a clay bed thirty feet or
more in thickness. Some of the clay of this deposit
is of most beautiful quality, and especially well
‘suited to the manufacture of the finest stone ware. A
‘set of china ware, 700 pieces, made from this clay
took a premium at the New Orleans Cotton Exposi-
tion.

In places the clay has streaks and stains, due to
iron, and in other places it has a dark gray color, due
to the presence of organic matter, which does not pre-
vent its burning to a white color. Much of ithe clay
is adapted to the manufacture of fire brick as shown
by the analyses of a sample collected by Dr. Ries,

80 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

number 119. Analysis, number 214,shows the quality
of the purer and whiter variety.

The clay deposits extend to within two or three feet
of the Devonian Black Shale, thus fixing the occur-
rence at the base of the Subcarboniferous formation.

Beds of potter’s clay of this formation have also
been noted at other localities, among them one in the
railroad cut just north of Stevens’ switch on the A.
G. S. R. R., and another in Calhoun county in 8. 19,
T. 15, R. 6 E.*

Hard white clay; like halloysite in appearance, has
also been noticed at points in ithe Tennesseee valley,
near Stevenson, and it is quite probable that search
in that valley would be rewarded by the finding of
deposits of the clay of commercial importance.

COAL MEASURES.

In some parts of the coal fields, the under clays of
the seams of coal have been utilized in the manufac-
tory of pottery, as at Jugtown, near Sterritt, in St.
Clair county; -t Fort Payne and Rodentown, in De-
Kalb; at Vance’s Station, in Tuscaloosa county; at
Summit, in Blount county, and at Arab, in Marshall
county. In all these places the clay is manufactured
into jugs, flower pots and similar articles, while at
Fort Payne it is also used in the manufacture of fire
brick.

The shales of this formation are also utilized in
some parts of the State, notably at Coaldale, where
they are made into vitrified brick for paving purposes.
At the Graves Coal Mine, near Birmingham, occur
two bodies of shale, which have been analyzed and

*Valley Regions, Part II., pages 441 and 741.

CRETACEOUS FORMATION. 81

otherwise tested for this report, and, the results of
these tests are to be found below, numbers 170 and
171.

Dr. Ries hag tested also the Carboniferous shales
from near Pearce’s. Mill, in Marion county, and finds
them admirably suited for the manufacture of pressed
brick and with a mixture of a more plastic clay suit-
able for the manufacture of terra-cotta (No. 3.)
Up to the present time none of the clays from the
Coal Measures have been found suitable for use in
the manufacture of high grades of fire brick, but this
may be due to the circumstance that very few of these
clays have beeen examined. Of shales suitable for
making vitrified brick, there is the greatest abund-
ance.

CRETACEOUS FORMATION.

In many respects the most important formation of
Alabama in respect of its clays, is the lowermost
division of the Cretaceous, which we have called the
Tuscaloosa. The strata composing this formation
are prevalently yellowish and grayish sands, but
subordinated to ithese are pink and light purple
sands, thinly laminated, dark gray clays holding
many well preserved leaf impressions, and great
lenses of massive clays varying in quality from al-
most pure white burning clays to dark purple and
mottled clays high in iron.

This formation occupies a belt of country extending
from the northwestern corner of the State, around
the edges of the Paleozoic formations to the Georgia
state line at Columbus. Its greatest width is at the
north-western boundary of the State, where it covers

82 GEOLOGICAL RELATIONS Of ALABAMA CLAYS.

an area in Alabama thirty or forty miles wide and
about the same width in Mississippi.

From here towards the southeast the breadth of
the belt gradually diminishes, till at Wetumpka and
thence eastward to the State line, it forms the surface
along a belt of only a few miles width.

To the eastward of the Alabama river, the propor-
tion of clay to the rest of the strata is less than in the
other direction, and at the came time the clays
themselves are as a rule more sandy. But from the
Alabama river northwestward, in the gullies, ravines,
and railroad cuts, there are many exposures of these
beds, exhibiting sections of clay beds from six to for-
ty or fifty feet in thickness, and of varying degrees of
purity. Ina general way we may say that the purer
clays, resmbling kaolin in composition, have as yet
been found only in the northern part of this area in
Fayette, Marion, Franklin and Colbert counties, and
the adjoining parts of Mississippi.

In my Coastal] Plain Report, published in 1894,*
I have brought together many details concerning the
Tuscaloosa formation in the counties of Lee, Rus-
sell, Macon, Elmore, Autauga, Chilton, Perry, Bibb,
Tuscaloosa, Pickens, Lamar, Fayette, Marion,.
Franklin and Colbert, and the reader is referred to
that book for full discussion of the formation.

In order, however, to present the clay occurrences:
as completely as possible I shall give extracts from
the Coastal Plain Report in so far as they may be
descriptive of the deposits of clay.

To these extracts are added a number of details
received from a report made by Dr. George Little,
who in 1891, spent several months making for the
Geological Survey ,some examinations of the clays.

*Pages 307-349, 531-2, 536, 541, 545, 549 554, 556, 559.

CRETACEOUS FORMATION. 83

of this formation. Dr. Little brought together a
large collection of the chief varieties of these clays
and from these specimens, many of the analyses
found in the report below have been made.

Use is also made of manuscript notes of my own on
examinations made since 1894 and of descriptions of
clay occurrences in the report on the Valley Regions,
Part I, by McCalley.

Inasmuch as the remarks of Dr. Eugene W. Hil-
gard on the clays of Mississipppi apply in general
to the clays of this State which lie immediately ad-
jacent to them on the east, a short extract from his
Report on the Geology and Agriculture of Missis-
sippi will not be out of place. These notes relate to
the clays occurring in Townships 4, 5 and 6 in Tish-
omingo county, Mississippi, and were published in
Dr: Hilgard’s Report on the Geology and Agriculture
of Mississippi, 1860.

“A large deposit of white clay of great purity, how-
ever, occurs in Tishomingo county, chiefly in the
southern portion of the territory of the Carboni-
ferous formation, following very nearly its western
outline. It there forms a regular stratum of con-
siderable extent, which .in one locality at least, was
found to be more than 30 feet in thickness. The bed
attains its best development, so far as the quality
of the material is concerned, in the northern portion
of Township 5 and in Township 4, Range 11 east,
where it is about 30 feet underground in the uplands,
though at times appearing in limited outcrops on ithe
banks of the streams. Northeastward and south-
westward from the regions mentioned, the bed also
occurs but changed in character, at least near the

surface, to a white gritty hardpan, or clays of various
colors and of much less purity. It forms the lowest

84 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

visible portion of the Orange Sand formation, and
is almost invariably overlaid by strata of pebbles and
pudding stone, which in their turn are sometimes
overlaid by common orange-colored sand.

The most southerly exposure of these beds, known
to me, occurs on a small branch of McDouglas’ Mill
creek, in Sections 5, 4, and 9, Township 6, Range 10,
east, near Mr. Pannel’s place. For more than a mile
along this branch there are exposures in which
about 20 feet of a whitish mass, varying from a fine
clayey sand to a white plastic clay, appears overlaid
by thick beds (20 to 40 feet) of ferruginous pebble
conglomerate; the latter in its turn being overlaid by
the common ferruginous sand and brown sandstone
on the hilltops. Similar outcrops appear in the
neighborhood of Mr. Aleck Peden’s place on Sections
3 and 27 ,Township 5, Range 10 east, northeast of
Pannel’s Here also a white stratum of which only
a few feet are exhibited is overlaid by pebble conglo-
merate, and this by the common Orange Sand. The
white mass varies from white plastic clay to fine.
grained aluminous sandstone; its upper layers are
sometimes composed of a singular conglomerated
mass, consisting of small, white quartz pebbles im-
bedded *‘n pure white pipeclay. In both localities,
copious springs of pure water are shed by the im-
pervious clay strata. At Mr. Peden’s, ithere is a fine
bold chalybeate spring which seems, however, to
derive its mineral ingredients (sulphates of iron and
magnesia and common salt) from the adjacent
Carboniferous strata rather than from those of the
Orange Sand. In either of the localities mentioned,
materials suited for fine pottery, or queenware,
might be obtained.

Thence northwest, the stratum is not often found

CRETACEOUS FORMATION. 85

outcropping, but, as had been stated, 20 to 30 feet
below the surface of the uplands; the country being
but slightly undulating. At Dr. Clingscale’s, Sec
tion 8, Township 5, Range 11 cast, the clay stratum
was struck at the depth of about 30 feet beneath sand
and pebbles; it was dug into, without being passed
through, for nearly 30 feet more, no water being
obtained from below, but dripping in above from the
base of the pervious strata. The whiteness and
plasticity of the material seems to increase with the
depth. The portion of what was dug out of
the well in question, had already been removed
at the time of my visit, having been used
for various economical purposes as, chalk,
whitewash, and “Lily White’. The specimens
examined were, therefore, rather below the average
quality, and on long exposure to the air, their surface
shows some yellowish spots. I found nevertheless,
that in baking at a high heat they yielded a biscuit of
greater whiteness than their natural color when
fresh; and that fine splinters, exposed for ten minu-
tes to the highest heat of the mouth blowpipe, retain-
ed their shape perfectly while reduced to a semi-trans-
parent frit. A quantitative analysis of the clay from
Clingscale’s well gave the following results:

White Pipe Clay from Clingscale's.

Insoluble matter... 0 ..essssesesescssscsssee cosescerpeeseaeasscesescensennveceteee eee OOLE77

VUNG erveceescesacnerieacianeveceavevines 3 abet als Sdenvinassssasvaveneesedenabaedeacatenvn 0.140
Mae titel secnaue dir uentszncies acterverres 3 weve tTACce
Peroxide of iron se vase» 0,126
ALOUIING iy accesacctsacessdeeiinexezedenereeeeeeeeeite eens Bissitstaacvaesieestala Ld:
WlGE ccecicenianicenitincinin Meee Gaenens 1am OOD

99.864

This analysis (which was made solely for the pur-
pose of ascertaining the ingredients foreign to the

86 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

clay proper) proves the singular fact that this clay,
though occurring in a formation characterized by
the large amount of iron it commonly bears, contains
a remarkably small amount of that substance, which,
together with minute porportions of lime and mag-
nesia, explains its infusibility.

The two most important practical purposes which
the materials occurring in the deposits just describ-
ed will serve, are the manufacture of fine queenware
and that of fire proof brick. (Not porcelain. Kaolin
or porcelain earth contains, besides the white clay, a
certain amount of undecomposed feldspar, which
imparts to it its property of being semi-fused at the
temperature of the porcelain kiln. The same prop-
erty might be imparted to the white clay in ques-
tion, by the artificial admixture of ground feldspar,
but it could not thus compete with the naturel kao-
lin of Alabama).

As for the queenware, the plasticity of the mate-
rial leaves nothing to be desired ; and since the amount
of siliceous matter varies greatly in different lay-
ers, there could be no difficulty about givng to the
mass the precise degree of meagerness which may
be found most advantageous, by mixing the several
successive layers. The same may be said with reference
to the manufacture of fire brick (to which these ma-
terials are admirably adapted), which would proba-
bly, at the present time, be the most feasible and most
profitable manner in which the beds could be made
available. The manufacture of fire brick differs from
that of ordinary brick in this, that it requires more
care, both in working the clay and in moulding the
brick. Beyond their fireproof quality, it is demanded
of fire brick that their shape be perfect, their mass
uniform and without flaws in the interior; also that

CRETACEOUS FORMATION. 87

they shall be liable to the least possible shrinkage in
a high heat. The latter quality is imparted to them
by a considerable mixture of either sand or ground
fire brick to the fireproof clay, which itself ought to
be thoroughly seasoned before, and then well worked
up with such additions of the above materials as may
be required. In judging of the amount of sand or
ground brick to be added, it is to be observed, as a
rule, to add as much as may be consistent with the
proper firmness of the burnt brick and with conve-
nient moulding. The latter process ought to be per-
formed, as in the manufacture of pressed brick, when-
ever a first-class article is aimed at, for it is only thus
that external and internal flaws are entirely avoided.
In some localities materials may be probably found
which reduire no further admixture—the strongly sili-
ceous varieties of the clay; but whenever sand or
burnt clay is added to the mass, care should be had
that it be free from iron, which would seriously im-
pair the fireproof qualities of the clay. None but
white sand should be used. For the rest, they may
be burnt in kilns like common brick.”

RUSSELL AND MACON COUNTIES.

Within the limits of Girard and Phoenix City, op-
posite Columbus, and in the hills to the west of Gi-
rard, are many exposures of the Tuscaloosa strata,
aggregating some 200 feet in thickness. These are
composed mainly of sands, but there are numerous
beds of white, gray and purple or mottled clays inter-
stratified with the sands. The small stream which
flows through Girard exposes a number of these clay
beds, and others are to be seen in the hills to the west
of the town. The materials for the manufacture of

88 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

drain pipe, vitrified brick, pressed brick etc., are here
in abundance.

These clays are to be seen at intervals along the
road leading toward Montgomery, e. g., near Marvyn,
Crawford and Society Hill, the prevailing variety be-
ing the mottled red or purple clay. Northwest of So-
ciety Hill these clays occur as far as Farrell’s Mill, in
Macon county.

Near Cowles’ Station, at the ferry across the Talla-
poosa river, purple clays, three feet in thickness, show
in the river bank, and a short distance further down
the river at the site of Old Fort Decatur, a fine sec-
tion of the Tuscaloosa beds, including many beds of
clay from one foot thickness and upwards is ex-
posed.*

ELMORE AND AUTAUGA COUNTIES.

In the vicinity of Old Coosada town, along the

banks of the river, about Robinson Springs and Edge-
wood, there are many occurrences of the clays of this
formation, analyses of which have been made by Dr.
Ries, and the results given below in the body of the re-
port. About Edgewood there are several potteries
and one ochre mine using the materials of the Tusca-
‘loosa formation. McLean, Vaughn and Boggs
have potteries here, and Pressley has one further
‘west.

At Chalk Bluff, near Edgewood, there is a very
characteristic section exposed in an ancient bluff of
the river, now at a distance of more than a mile from
that stream. The section is as follows:

*Coastal Plain Report, p. 554, 556.

CRETACEOUS FORMATION. 89

Section at Chalk Bluff, Elmore County.

1. Layette red loam and pebbles... ........... 15 feet
2. Gray and yellow sandy clays, in distinct but
Trregular ayers) sscesicc, wsersahdene 60 aveveieneia 6 “
8. White clay, 3 feet graduating downwards into
yellow ochreous clay, 3 feet ...........055 6. “

4. Gray plastic clay blue when wet, and exceed-
ingly tough and sticky; full of vegetable
remains, flattened and bituminized ........ 10 “

Two samples of this clay (Nos. 101 and 122) have
been tested and analyzed by Dr. Ries (see below un-
der the head of Pottery Clays and Brick Clays), where
a section of this bluff is given, differing slightly from
the above. This is not to be wondered at, since ‘the
stratification is very irregular, and no two sections,
twenty feet apart, are idential.

Along the line of the Mobile and Ohio Ry., in Auta-
gua, and on most of the pubilc roads leading from
Prattville north and northwest, there are exposures of
Tuscaloosa strata, consisting of sands and clays, the
former predominating. In the western or northwest-
ern part of the county, near Vineton, many instruc:
tive sections of the Tuscaloosa beds are to be’ seen.
Some of these sections include beds of clay, which are
of interest in our present work.

Section, near Col. J. W. Lapsley’s place, Vineton.

1. Stratified clays of white, pink, and purple
colors, interlaminated with thin sheets of
yellow sands; the lower part of this bed has

a larger proportion of sand .......-++eeees 10% feet
2. Gray laminated clay with partings of purple
sands .......25 esses Ag avebapbewibente se erm we 5

3. Yellowish white laminated clays, with purple
and other ‘bright colors on the dividing
planes, 5 feet showing, but the same beds
appear to continue down the hill for at least
ten feet further ........ cece eeee te eeeee 15

90 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

Section No. 2, near the preceding.

1. Yellowish sands, beautifully cross-bedded.... 4 feet
2. White and pink clays, interbedded with yellow
SANS: cic isaivee. wears Gees TS SS MHS VE QRS 10 “

Section No. 8, same locality.

1. Purple clays interbedded with reddish sands. . 6 feet
2. Mottled (red and yellow) sandy clays, partly
obscured by overl.ying pebbles and sands...... 12:
8. Red sands with small lenticular bits of yellow
CDV ccscycee ea wah dd SER Ree bse ye Ree iB.
4. White and yellow laminated clays ......... 6to8 *

At the bridge over Mulberry, near Vineton, the fol-
lowing strata are shown in the banks of the creek:

Section on Mulberry Creek, near Vineton.~

1. Mottled purple clays, similar to those at

Steele’s Bluff on Warrior River ........... 5 feet
2. Yellow cross sandy beds ............02e0eee Die oes
8. Mottled clays sandy below .......,.-.++--- 5
4. Grayish white m caceous sands, with irregular

patches of red and yellow colors; to water's
COE site Wraiat ee SOG IE Ey RS AG ee a

BIBB COUNTY.

From ‘Vineton up to Randolph very little of the
strata of the Tuscaloosa formation can be seen until
within three miles of the latter place, where dark pur-
plish gray clays are to be encountered. Between Ran-
dolph and Centerville, along the public road, and at
many points along the railroad fom Mapleville to
Centerville, there are occurrences of the massive clays
of this formation. These clays have given much
trouble and caused much expenge to the railroad,
from the fact that when softened by the winter rains
they squeeze out into the railroad cuts, filling them up
and overflowing the track. Where the clays from the
cuts are used to make embankments, they are equally
troublesome, as they are continually giving way. We

CRETACEOUS FORMATION. 91

have no accurate notes of the sections exposed in the
railroad cuts but the public road from Randolph to
Centerville has been. somewhat closely examined.
At Soap Hill there is a typical section as follows:

Soap Hill, 7 miles East of Centerville.

1. Purple and mottled clays at summit of hill... 5 feet
2. Clayey sands in several ledges .............. LON
3. Cross bedded yellowish and whitish sands,
traversed at intervals by ledges of sandstone
formed by the induration of the cross-bedded

Sands 22.6665 64 iba Raine” ENN ke) aRhalaaanen 30 “
4. Laminated gray clays with partings of sand.. 10 “
5. Alternations of laminated gray clays with

cross-bedded sands in beds of 12 to 18 inches

thicknéss- .:caccceas “sicaadeas <ddadtenceinn 40 “
6. Yellowish cross-bedded sands with clay part-

TOES corps ous Mes eae Ae La eeee~ Metherda 20 “
7. Laminated gray sandy clays containing a few

leaf impressionS ........ cee eeeeee eeeee 10 “
8. Grayish white sands ......... ...... aeeeee so"

On the same road in the eastern part of the town of
Centerville, on the School House Hill, there may be

seen some fifteen feet thickness of purple and yellow
clays.

The same beds show along the Selma road, south of
Centerville, at many points. Sections are given in
thie Coastal Plain Report, pages 336 and 338. To the
southwest of Centerville also, in townships 21 and 22,
ranges 7 aud 8, many of tthe ridges are composed of
purple clays eight or ten feet in thickness, resting on
four to six feet of gray clays.*

On the road to Tuscaloosa the clays show about half
way between Centerville and Scottsville.

Along the line of the Alabama Great Southern Rail-
road in this county, there are many exposures cf the
Tuscaloosa clays, e .g. at Bibbville, where they have
been utilized for many years in the manufacture of
semi-refractory fire bricks for grates, etc. A great

*Costal Plain Report, page 338.

92 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

deal of the material is shipped now to Bessemer,
where it is worked up into fire brick. Further north,
near Woodstock again are rather extensive diggings
on the line of the Birmingham Mineral Railroad,
from which the clay is shipped to Bessemer and used
as above indicated.

Dr. Ries has investigated the clays from both of
these localities, and his results are given below in the
body of the report, under No. 112 for the -Bibbville’s
specimen, and No. 111 for that from Woodstock. He
classes them with the fire clays. Another specimen
from Woodstock, classed by Dr. Ries as brick clay,
has been tested, (No. 126, A. Stevens).

TUSCALOOSA GOUNTY.

The utilization of the clays of this formation was
begun in Tuscaloosa county by Daniel Cribbs in the
year 1829. He was the pioneer, though it is said that
W. D. Preston had a pottery in Autauga county in
1828. C. K. Oliver has had a pottery in this county
since 1856. Peter Cribbs, in Lamar county, carried
on the business for. twenty-five years. He was the
brother of Daniel, whose son, Harvey H. Cribbs, has
for many years been more or less engaged in working
the clays along Cribbs Creek, two miles south of Tus-
caloosa, and later four miles east of town on the Ala-
bama Great Southern Railroad. The Lloyd family
have operated several potteries in Marion county, Al-
abama, and Itawamba county, Mississippi, for many
years. Fleming W. Cribbs, a son of Peter, has now a
pottery at the new town of Sulligent, on the K. C. M.
& B. R. R.*

Within the limits of the city of Tuscaloosa there

*Notes of Dr. George Little.

CRETACEOUS FORMATION. 93

are many exposures of the clays of this formation in
the gullies facing the river bottom. In one of these
gullies the section is as follows:

Section in Tuscaloosa.

1. Pebbles, sand, and red loam of the Lafayette
forming the plateau on which the city of
Tuscaloosa stands ......... Jee eee scene 15 feet

2. Light gray, somewhat massive clays, mottled
with yellow, but becoming laminated below 3

3. Dark blue, nearly black laminated clays, lam-
inae half an inch thick, separated by thin
partings of white sand. The clay contains
leaf impressions ...... 0 ...csee eee renenes 3

4. Yellowish gray laminated clays, also containing
impressions of variable thickness, average 2 “

5. Strongly cross-bedded sands, yellowish to
white, sharp, with a few streaks of clay ir-
regularly distributed through it.......... 20 “

At the proper depth below the surface, the clays
above mentioned are encountered in most parts of the
plain, though naturally the thickness of the beds and
‘their character vary from place to place.

Eastward from the city the cuts of the A. G. S. rail-
road exposes these clays at numerous points. Some
four miles from town they have been utilized by Mr.
Harvey Cribbs in the manufacture of flower vases,
jugs and similar wares. Below about twenty feet of
the surface red loam and pebbles, we find at this place
one to twelve feet of white clay, free from streaks;
then three feet of yellow sand and a bed of blue clay
of undetermined thickness.*

D. Ries’ analysis and tests of the Cribbs’ clays are
given below under No. 1, 8., where it is classed among
the pottery clays.

At the Box Spring, about five miles east of Tusca-
loosa, the railroad cuts expose about six or eight feet
of laminated gray clays marked with purple streaks.
Beyond Cottondale, nine miles from Tuscaloosa,

*Notes of Dr. George Little.

94 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

about thirty or forty feet thickness of purple clays is
seen along the hillside.

Some twelve miles east of Tuscaloosa the grayish
purple clays appear in many places along the slopes
of the hilis. The following general section of strata
in this vicinity will give a good idea of the formation :

Section 10—12 miles East of Tuscaloosa.

1. Purple massive clays ..........:ee eee eeee 5 feet
2. Ferruginous sandstone crusts ........-.+-- 6 to 8 inches
3. Variegated clayey sands holding small pieces

Of purple (CLAY gciicwisrrsursnae aaa wee 10 feet
4. Purple clays with partings of sand .......... 10 “
GS, Feeriginous CMst acacxe ecavae senevnenese 3 aa
6. Laminated gray and yellow sandy clays ....6 to8 ‘“
7. Lignite with pyrite nodules .............. 2 to 6 inches
8. Dark gray somewhat massive clays ........ 6to8 “*
9. Strata obscured by debris from above ...... 20 “
10. Purple clay at base of hill, thickness undermined.

Along the A. G. S. R. R. beyond Cottondale, the
cuts show many varieties of materials of this forma-
tion, among them beds of purple clays, sometimes
massive, sometimes laminated. Just beyond Cotton-
dale the clays gave much trouble many years ago at
what was known as the “Sliding Cut.”

A mile or two beyond Vance’s Station, a bed of these
clays is now being worked for material to use in the
manufacture of fire brick at Bessemer.

Southward from Tuscaloosa the clays are seen in
most of the hills bordering Big Sandy Creek, and
judging from the width of the outcrop along the hill-
sides there can not be less than fifty feet thickness of
them.

The same clays show along the A. G. S. railroad at
Hull’s Station, and all that vicinity, and Dr. Ries pre-
sents an analysis, together with the physical tests,
of a sample of this clay, No. B., which he classes as a
refractory or fire clay.

A characteristic section of these clays exposed

CRETACEOUS FORMATION. 95

along the hillsides, just south of Big Sandy, where
the Greensboro road passes, is given below:

Section on Big Sandy Creek, Tuscaloosa County.

1. Purple or mottled clays, like those occur

ring at Steele’s Bluff, on Warrior

TIVCM ss .caea. saedee Aeveee chen eedan 30 feet
2. Light yellow sands with pebbles, also sim-

ilar to those seen at Steele's and

WHS BAGG. s anacnees Kee rewan 10 to 15 feet
3. Gray, laminated clay, enclosing a ligni-
tized tree trunk at base of hill...... 4 to 5 feet

Further south the materials of the Tuscaloosa for-
mation seem ito be more sandy, and the proportion of
clays is small.

Along the banks of the Warrior river below Tusca-
loosa, the clays show up in many places, especiaily in
the vicinity of Saunders’ Ferry.

At the Snow place, above the ferry, there are some
great gullies, in which these sands and clays of the
formation are exposed. In some of the clay beds
many leaf impressions have been obtained, which

have assisted in the determination of the geological
horizon of the Tuscaloosa formation.

A short distance above the ferry, and adjoining the
Snow place, there is a bluff about 140 feet high which
shows the clays and other beds of this formation
very clearly. The section is as follows:

Section above Saunders’ Ferry, Warrior River.

1. Massive clays of greenish and purple colors,
breaking with conchoidal fracture.
On drying these clays become hard and
rock-like. When wet by the winter
rains, they soften and slide down the

slopes, covering them completely

in places. Thickness.... ...... eae 40 feet
2. Laminated sandy clays, gray, with sand

PAPEIBES: cawesey anak sitaveueveee a 5 feet

8. Gray cross-bedded sands, with partings of

clay along many of the planes of

false bedding; .0s622 .cviees savnas 25 feet
4. Gray cross-bedded sands and blue mica-

CEOUS SANGS...... cece eens cee ene oe 23 feet

96 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

At Williford’s landing the purple clays show about
ten feet in thickness below the second bottom, or river
deposits.

At Steele’s Bluff, and a few ‘miles below, at
White’s Bluff, similar purple or mottled clays make
about ten feet thickness of the river bluff.

Westward and northwestward of Tuscaloosa the
clays appear along all the roads for many miles to
the western boundary of the county, and beyond into
Pickens. The clays when freshly exposed are of gray
color, but undergo a series of changes in consequence
of weathering, and the oxidation of the iron which
they contain. Tirst, the gray becomes specked with
red, and this color gradually increases in proportion
until it prevails, and the whole body of clay becomes
a dark red or purple mass, with few, if any, of the
fragments of the original gray color.

At John Mills’, about thirteen miles from Tusca-
loosa, on the Shirley Bridge road, 'the following sec-
tion is made by Dr. Little:

Section in Tuscaloosa County.

1. Red loam and sand (Lafayette)............ 10 feet
2. Ferruginous sandstone crust.... .... ...... 6 feet
8. Blue clay (Sample No. 1)...........eeeeeee © feet
4. Yellow sand, with indurated crust above and

DOW ver244e° GHwHL SRHSSRAO GRETA N- Mes 7 feet
5s Blue Clay (CNG: 29. a osc escepeer alas o.8 0808 4 eralavauene 6 feet
4. Yellow sand, with indurated crust above and

On the Fayette Court House road the same clays
show at many points, but the most promising clays
along this road have been observed beyond the Tusca-
lcosa county line in Fayette.

The Mobile and Ohio road to the northwest of the
city of Tuscaloosa exposes in many of its cuts beds of
clay, which have been a source of much trouble and
expense house of the filling of these cuts fy the

CRETACEOUS FORMATION. 97

softened clay during the winter seasons. Several cuts
in the vicinity of'Ten Mile Cut have traversed these
beds of clay. One specimen from the Ten Mile Cut
has been examined by Dr. Ries, and classed among
the brick clays (No. A), though, as Dr. Ries remarks,
there is no reason why it should not find other uses as
well.

In the near vicinity of this cut, on land formerly
occupied by Mr. J. C. Bean, occur three beds of clay
measuring each about five feet thickness. These have
been investigated by Dr. Ries under the Nos. 118, 115
and 100. The first of these, classed as fire clay, has
many points of interest, growing out of its dense
burning at low temperature, and the great difference
in temperature between the points of incipient fusion
and vitrification, suggesting its suitability for use
as a glass-pot clay. The other two clays are classed
as pottery clays, and are perhaps representative of
one of the most widely distributed types of the clays
of this formation.

PICKENS COUNTY.

Near the line of the M. & O. road, in this county,
the clays are observed from the Tuscaloosa county
line to within nine miles of Columbus. In mode of
occurrence and in the character of the clay these beds
resemble those of Tuscaloosa, above mentioned. Irom
Roberts’ Mill on Coal Fire Creek, Dr. Little has col-
lected a sample of white clay which ‘has been analyzed

by Dr. Ries, No. 328. It is classed by him among the
stone-ware clays, burning to buff color, and is in
many respects similar to the Cribb’s clay of Tusca-
loosa. West of Coal Fire Creek, and at a distance of
18 to 20 miles from Columbus, the massive reddish
clays show in the hills to a thickness of 40 to 50 feet.*

*Notes of Dr. George Little.

98 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

LAMAR COUNTY.

The strata of the Tuscaloosa formation cover the
entire area of Lamar below the mantle of red loam
and pebbles of the Lafayette. Among the strata are
numerous beds of clay of varying degrees of vurity.
| Dr. Little’s notes, which follow below, give many
details concerning them.

Along the line of the Southern (Georgia Pac'fic)
Railroad, there are many exposures of the clays, as
at Millport, where the clay shows at a thickness of
four feet; beyond this at about 23 miles from Fayette
Court House, the clay seems to be 10 feet thick, and
near this at Fernbank, J. D. Green has a pottery.
His clay is 18 feet thick, analysis of this clay is to be
found in Dr. Ries’ report, No. 27 S.

Along the road from Fayette Court House to
Vernon, at 9 miles from the former place we have this
section.

Section nine miles west of Fayette C. H., in Lamar Co.

Ble: Clay sisece wid, aiedatdels Bie yeaa a) AueNeiees Baa 4S 6 feet

Mottled Clays: sonadess Gee chan @ieed ieee ens 20 feet
BABdY CAF ceevsae 2448 GAGSRS Rewnn eee bees 4 feet

Three miles further west on the same road, this clay
is some 20 feet in thickness. Within two miles of

Vernon, in A. W. Nichol’s well, blue clay 8 feet thick
is penetrated below six feet of overlying sands.

One mile east of Vernon, at a saw mill, there is clay,
white and 3 feet in thickness.

On the old military road of Gen. Jackson at a dist-
ance of 20 miles from Columbus, Miss., and about 7
or 8 miles northwest of Vernon, near Bedford P. O.,
are the remains of a pottery once owned by Peter
Cribbs. At this place lives Captain Cribbs, a negro
man with his son, Major. Captain worked for

CRETACEOUS FORMATION. 99°

“many years in the potteries, which his master, Peter
Cribbs and his master’s widow, managed from 1865
to 1886. The pottery, 3 miles further north on the
Military road near M. P. Young’s, was the place
where most of the jugs, jars, etc., were made. The
best of the clay for these potteries was obtained from
what is now Reuben Powell’s land, 2 miles west of
the Military road in the northwest quarter
of the norhwest quarter of S. 28, T. 14, R. 16. The
pits were dug 14:feet down to the clay, which
was 3 feet thick. Mr. Powell has bored with an 8 inch

- augur near this place, and found clay 14 feet from the

surface, 5 feet thick, dark brown and very tough and

plastic. Analysis of this clay is given by Dr. Ries
under No. 11 §.

Lewis J. Jones, who now lives on the Powell place
in the southwest quarter of southwest quarter of
Section 23, has bored a well in his yard of which the
section is as follows:

Section in Well, Lamar Co.

Surface sands and loams................ Moats Sexe 12 feet
Cewek ck 2hEA OR BEG OEE See eke eee 1% feet
BAe ccse arteKee gu geaeeeiae Pehewe Ka dSee 9 feet
RAP oleae. -yevear ie Beeeenys 6 dears ee- KREAAS 2 ~~ feet
WhHIlC 8aNd .sircice Gerednetys sax nee exeemes 24 = feet
Clay, penetrated to depth of..... eee fee 2 ~~ feet

but so tough that the auger could not be raised,
and the well was stopped.

Clay is also reported at Thomas’ Mills, above Hun-
nel’s Bluff on Buttahatchie creek and on Wilson’s
creek near Friendship Church.

Westward from the Military road, the clay iterri-
tory continues to within 10 miles of Aberdeen, where
level land and white sandy soil set in.

Gattman is on the Mississippi State line, and just
west of it across Buttahatchie is Greenwood Springs,4
miles from Quincy in Monroe courty, Mississippi.

100 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

One and a half miles south of these Springs, there
is a railroad cut 85 feet in depth, the largest cut on
the road, (K. ©. M. & B.) 110 miles from Birming-
ham. In this cut we find the following section: °

Sections along K. C. M. &€ B. R. R., Lamar Co,

Yellow loam....... ep KERR ues wie wiemnieneds 5 feet
NeMOW SANs ges canis axwawEn Spe leae QeArerveenes 15 feet
Yellow sand with streaks of clay........---++-++- 5 feet
Blue micaceous clay, sample No. 11, A....-....-. 5 feet

Half a mile further west another section:

Yellow ClaYowis scesatink spec esas: es Sines eRRAE 5 feet
Ferruginous sandstone, used for ballast.......... 10 feet
Mellow Sandcsccas seaves Se ¥egeed se auw newer 20 feet
Clay with sandy layers...... ....ceceeeeeveee 8 feet
Compact b'ue micaceous clay, NAHI Yani kas ses 12 feet

At mile post 111, the section is:

Red: CIA, cui sicieetiawuie sotied Beet wraateate 10 feet
Banded red and white cay... . ceceec eee eeeeeee 10 feet
Pore; Sand) wecaccwiw sews s “i ew wiwemancere snare 10 feet

Half a mile west of the 111 mile post, the section is:

Red loam of the Latayette formation............ 5 feet
Bright yellow sand........ ...eeeee eeeeeevees 80 feet
(0) Ch nr cc 2 feet
wight yellow sandy clay...... cscs eee cece eens 20 feet
Red and white clay... ...ccecnene coerencsseee 5 feet

Near the State line, on the Kansas City, Memphis
and Birmingham Railroad, 3 miles from Sulligent on
the west side of Buttahatchie,a pottery has been oper-
ated. At Sulligent, Fleming W. Cribbs has lately
started a pottery. Heisason of Peter Cribbs and
nephew of Daniel Cribbs. His clay bed is,one-half
nile east of Sulligent and is 4 feet thick, and white.
He says that his father carried on the business from
1838 to 1853 when he died, and his widow continued
the work to 1863, his account ‘agreeing with that of
the negro, Captain, nearly as to time of operation,

CRETACEOUS FORMATION. 101

but placing it in entirely different decades. He has
orders now for 5000 gallons (jugs) from Birmingham
and Bessemer, at eight cents a gallon. He has two
hogback kilns with a capacity of 800 jugs each. His
clay is found in a washed out old road and is overlaid
by 10 feet gravel.

‘Rye has a pottery, 6 miles north of Millville, Detroit
P.O. Davidson Brothers have one also in same neigh-
borhood. Lloyd has one near the Mississippi line in
Itawamba county. These compete with potteries at
Holly Springs, Mississippi, and Pinson’s 12 miles
from Jackson Tenn., for the West Tenn. and Miss.
trade. From State line at Gattman to Glenn Allen,
clays are very abundant and of fine quality all along
the Kansas City Railroad, and this is destined to be
an important center of trade in all kinds of clay
manufacture. Beaver Creek flows nearly west, par-
allel with the railroad. Beaverton is a station on Sec-
tion 17, Township 13, Range 14 west. One mile west
of William Brown’s place, Section 10, and on Ed-
mund Barnes’, Section 16 and on Ira Sizemore’s, Sec-
tion 17, clay abounds. Brown has ten feet blue
clay overlaid by 10 feet cross banded yellow sand. 5
miles east of Beaverton and 2 miles west of Guin,
there is 10 feet white and yellow sand and underlaid
by 3 inches of ferruginous conglomerate.

FAVETTE COUNTY.

Over the greater part of the area of Fayette county,
the strata of the Coal Measures are covered, to a
depth increasing as we go westward, by beds of the
Tuscaloosa formation capped with the red loam and
pebbles of the Lafayette. Among the strata of the
Tuscaloosa there are many beds of clay of purple,
gray and white colors. About the Court House, a bed

102 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

of white clay is reached at many points below a vary-
ing thickness of overlying strata. Thus at Mr. Sam
Appling’s a bed of fine white clay, 6 feet in thickness,
‘is cut in a well, and apparently the same bed is known
to underly the region about the depot. Mr. Appling’s
is in Section 24, Township 15, Range 13 west.

From Dr. Little’s notes, I am able to give a number
of details of the occurrences of these clays. Seven
miles from Fayette Court House, on the road to Mc-
Collum’s Bridge, is a bed of three feet thickness of
very pure clay ,hard and firm, which breaks up on ex-
posure into nodules, and the same bed shows on an-
other road to the west of this about one mile, south of
Wallace’s Mill on Gilpin’s creek, on W. D. Bagwell’s
land.

Dr. Ries’ analysis of this clay is to be found in the
report under number 67, 8.

On the road to Pikeville, seven miles from Fayette
Court House, we have the following section:

Section seven miles. north of Court House, Fayette Co.

Red loam of Lafayette........ 2c. cc ee cece eeee 2 feet
Geavel eure thee AREeS BN FAG eee RACV ON dee RAGS 10 feet.
Clay eases cassia e eeT se ayslee RARER. « Bert ee aie se 3 feet
Gravel enceitis Seesiecesysualay vatty Gyecbvaiane « iehalano es teiedneaats 3 feet

Between the depot and the Court House Dr. Little
has observed three feet of good white plastic clay in a
ravine on the roadside, and the same bed is exposed
in the ravines at many points on the eastern edge of
the old town. Five miles west of the Court House on
the Vernon road, some tan-yard vats were dug years
ago, three feet into a blue clay. About half a mile
from the depot, Mr. Joe Lindsay reports fine white
clay, twelve feet{ below the surface, which, he says,
was twenty feet thick.

To the westward and southwestward of the town

CRETACEOUS FORMATION. 108

along the line of the railroad, the clay shows in a cut
one mile from the depot. On the Columbus road, four
miles from Fayette, a six foot bed of clay is recorded,
and five miles further west, at Hezekiah Wiggins’ a
bed of blue clay, four feet thick. Dr. Ries has tested
and analyzed this clay under No. 32, 8.

Half a mile further west, at Henry Wiggin’s, there
is a bored ‘well, eighty feet deep, which, below the
depth of fifteen feet, seems to be mostly in clay. One
fourth of a mile beyond this, near Waldrop’s, a bed of
blue clay, 10 fet thick, shows at the bottom of a hill,
and fifteen feet higher up another bed appears.

Along the road to Tuscaloosa at seven miles from
Fayette, and also a mile further on, clay, three feet in
thickness, is exposed. Again in section 13, township
17, range 12, about a quarter of a mile from Shirley’s
Mill, several beds of clay are shown along a hill side.
One of these beds, a brown clay, about three feet in
thickness, is full of finely preserved leaf impressions.
and below it a fine sandy clay of three feet thickness.
This is near the 11 mile post from Fayette.

Dr. Ries has analyzed two samples of the clay from
this place under the numbers 68, S., and 110, and the
reader is referred to these analyses and the remarks
of Dr. Ries below.

Two miles southwest of Shirley’s Mill on Davis’
Creek, J. W. Black reports four feet of blue ciay in
section 25, township 17, range 12 west.

Near Doty’s piace, one mile east of Concord Church
and about thirteen miles from Fayette, there is the
following section exposed in a gully:

' "Section near Doty’s, Fayette Co.

Red loam and sands of the Lafayette............ 4 feet
Ferruginous sandstone crust........ «++-- pete 2 inches
White clay (No. 7, Dr. RieS)......00eeeeeeeeeee 6 feet
NMEMOW SANG ccc Leesteeeie sas Geet haecaure 5 feet
Variegated clay (No. 71, Dr. Ries)........-..+-+ 2 feet
White. Sand eccigcs ive iirc sec aueceieie: Heda el ee E EES 2 feet

104. GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

Dr. Ries’ analyses of the two clays here exposed
may be seen below under numbers 70 and 71.

MARION COUNTY.
®

While the strata of the Coal Measures underlie the
entire area of Marion county, yet these rocks do not
form the surface over any great proportion of this
area, since they are very generally hidden, except
along the valleys of the streams, by overlying mea-
sures of the Tuscaloosa and Lafayette formations.
Among the strata of the Tuscaloosa, here as in Fay-
ette, we find many fine beds of clay. Here again, Dr.
Little has collected many details of the occurrence of
these clays and what follows we take mainly from his
notes, though use is made also of what has been pub-
lished in my Coastal Plain Report, pages 331, 332 and
333.

In the lower part of the county along the line of
the K. C. M. & B Railroad, clays are exposed in rail-
road cuts all the way from Eldridge to Guin.

From New River crossing near Texas P. O., on to
Glen Allen, several beds of clay, of no great thickness,
are to be seen. A mile east of Glen Allen, in what is
known as Stewart’s Cut, we have the following sec-
tion: :

Stewart’s Cut, one mile’ east of Glen Allen.

Gray laminated clay with fine leaf impressions... 25 feet
Ferruginous sandstone crust_of irregular thickness 1 foot
Cross-bedded sands of yellow and pink colors..... 25 feet

The uppermost of the beds, above named, contains
many beautifully preserved leaf impressions which.
are very easily gotten out. The clay has been ex-
amined by Dr. Ries under No. 18, S.

At another cut, half a mile nearer Glen Allen, we

CRETACEOUS FORMATION. 105

find twenty feet of white sand with two feet of white
clay, and below this'a blue plastic clay extending be-
low the railroad track.

This sand has been shipped to Memphis as mould-
ing sand for the foundry. At Glen Allen, Dr. Little
gives this section:

Section at Glen Allen, Marion Co.

BROWN, CLAY e614 oc. aun eiame “Said herd aeaeransy Ayaneraeuenateiere 12 feet
MOLOW (GANG: sissiciacsin done. iecicd Ratt See ean Mo Maya sa lel 12 feet
White: pipe: Cla yiecasisnn aay vee eeieete eer eka 2 feet

Two miles east of Guin, on the same road, Dr. Little
observes five feet of clay below a capping of red sand,
and one mile west of Guin, (six miles from Beaver-
ton) he gives the following section:

Section near Gwin, Marion Co.

Cross-bedded yellow sandS...... sc... eee weeeee 10 feet
ClO yiecia Aaa etee aoas Saba eels Ge peed) ease 4 feet
MSE Ci diasieisijacig ss lerarallalars ia fe tyeetigned alinaieds. waded BOA 3 feet
Banded: Clay's sires s clang ocx areas 6 aisdisada ees oo 4 3 feet
DAMA visuaiar Wak sen oomvedig ao wet aun Glee ls “ads tn eee) ae) a eae 3 feet

On the South Fork of Buttahatchie in the vicinity
of Pearce’s Mill, there are several occurrences of clay
and shale worth consideration. D~. Ries collected
specimens from near the mill and gives his analyses
of two samples under No. 1 and No. 2, both of which
he classes as refractory or fire-clays. He also gives
his tests of some shales of the Carboniferous forma-
tion, which are well adapted to the manufacture of
vitrified brick (No. 3). Another sample of hard and
perfectly white clay was collected by Dr. Little from
near the top of a hill one-fourth of a mile east of the
mili. This Dr. Ries has analyzed under No. 36, S.,
and it is classed by him as a china clay. Dr. Little
reports that, in pulverized condition, it is used as a
face powder by the ladies in the vicinity.

106 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

It is, however, in Townships 9 and 10 and Ranges
11, 12 and 18, that we find the most important de-
posits of clay in this county. The typical locality of
its occurrence is at Chalk Bluff, which gets its name
from the white clay. Specimens collected by myself
were analyzed by Dr. Wm. B. Phillips and results
published in the Coastal Plain report, page 346. Dr.
Little’s sample was collected on the land of J. J. Mit-
chell, in northeast quarter of Section 8, Township 10,
Range 13, from a bed five feet in thickness. The an-
alysis of this is given below under No. 38, 8., and on
the same page Dr. Phillips’ analysis is reprinted.
This locality gives the name to the postoffice. In the
same quarter section, Dr. Little bas collected a.
sample from Briggs Frederick’s land, and the analysis
of this is given by Dr. Ries under No. 37, 8.

Another sample from the same locality from land
of Mrs. Susan Nelson, has been examined by Dr. Ries,
(his number 85). The same clay is reported by Dr.
Little as occurring southwest of Chalk Bluff at M. E.
Gassett’s, Section 13. Township 18, Range 10, as well
as at a number of localities within a radius of five or
six miles around Chalk Bluff. This clay is hard and
white, approaching pure kaolin in composition. It is
in a bed, five to seven feet in thickness, and needs only
facilities for transporte tion to become one of the most
valuable deposits in the State.

Between Pikeville and Hamilton, clays are of fre- —
quent occurrence, one of these near the former place
and some ten miles from Hamilton, collected by Dr.
Little has been analyzed by Dr. Ries, (No. 65, S.)

Westward from Hamilton to the Mississippi line
and beyond, Dr. Little reports many occurrences of
clay of various qualities. From the vicinity of
Bexar, three, samples of clay have been collected by

CRETACEOUS FORMATION. 107

Dr. Little and analyzed by Dr. Ries, (numbers 12,
40 S. and 41 S.). The bed in this region is about
four feet iw thickness. Nos. 12 and 40 are from H.
Palmer’s and No. 41 from Bexar, a mile further west,
near Pearce’s Store and Mill.

Near the State line on the road to Tremont, Miss.,
twenty feet thickness of clay is reported as being cut
in a well.

Beyond the State line, the clays continue, and at
Davidson’s Store, Lloyd’s pottery, they are put to a
rather remarkable use, namely for head stones of
graves, for which purpose they are moulded into flat
tablets, provided with suitable inscriptions and then
baked. These stones appear to be quite durable al-
though necessarily liable to be broken.

A number f potteries in this vicinity use this clay :
which is about four feet in thickness, and quite
similar to that mentioned above as occurring about
Gattman in Lamar county, on the K. C. M. & B. Rail-
road.

The Bexar variety of clay extends for a good many
miles northward up Hurricane Fork and along Bull
Mountain Creek.

.

FRANKLIN COUNTY,

In Franklin county the underlying Paleozoic rocks
of Carboniferous and Subcarboniferous ages are ex-
posed along the valleys of the streams, but every-
where else are covered with a mantle of varying
thickness of the sands, clays and pebbles of the Tus-
caloosa and Lafayette formations.

As in the other counties adjoining towards the
south, so in this, it is in the Tuscaloosa strata that we
find the important deposits of clay. In parts of the
county, especially in the vicinity of Russellville, val-

108 GEOLOGICAL RELATIONS OF ALABAMA OLAYS.

uable deposits of limonite or brown iron ore have
been for many years and are now being worked to
supply the furnaces at Sheffield and Florence.

Associated with these ore beds are clay horses,
as they are called, which, in places, yield an abun-
dance of fine white clay.*

Other occurrences of the clays of the Tuscaloosa
formation, not associated with the iron ores, have
been recorded by Dr. Little, from whose notes the fol-
lowing details have been obtained.

On the southern boundary of the county, near Sa-
voy postoffice, in T. 8, R. 14, near Dr. Kilgore’s Mill,
a bed of blue plastic clay three feet thick is noted,
above which, one hundred feet up the hill, is a bed of
four feet thickness of red clay or ochre (red chalk),
and just above this a bed four feet thick of pure, hard,
white clay, like that of Chalk Bluff, in Marion coun-
ty. The same beds are to be seen at many points
around Savoy within a radius of three miles. Half
a mile west of Burleson a bed three feet in thickness
of white clay is found immediately overlying the blue
limestone of the Subcarboniferous formation. Along
the road from Burleson to Belgreen the clay is ex-
posed at several points. .

Northwest of Russellville, on the road to Frank-
fort, large deposits of white clay were reported, but
not seen by Dr. Little.

Near the State line, in S. 9, T. 7, R. 15, on Gilley’s
branch, occurs a bed of clay from which material ‘has
been obtained for a pottery formerly worked by Mr.
Chaney, two miles east of Pleasant Ridge, Miss.

Southward of. this locality, in S. 20 and S. 29, of
T. 8, R. 15, Mr. Thomas Rollins has a bed of clay four

*Valley Regions Report, Part I, pages 211 and 215.

CRETACEOUS FORMATION. 109

feet in thickness, a sample from which has been tested
by Dr. Ries, No. 62 S. The country for several miles
in all directions about Rollins’ is rough and hilly, the
hills capped with beds of pebbles and a ferruginous
sandstone crust, but the beds of clay, interstratified
with sands, seem to make up a very considerable pro-
portion of their bulk.

COLBERT COUNTY.

In the northern and eastern parts of this county
the strata of the Subcarboniferous formation make
the surface, but in the southern and western parts
these older formations are covered by the mantle of

sands, pebbles and clays of Tuscaloosa and Lafayette
formations, the former of which carries the impor-
tant clay deposits here as elsewhere. The best of
these clays occur near the western border of the
county, as well as in the adjacent parts of Missis-
sippi.

The station Pegram, on the Memphis and Charles-
ton Railroad, seems to be about the central point in
this clay region. Some extensive works for the man-
ufacture of fire brick and other kinds of brick have
been established here under the name of the “Ala-
bama Fire Brick Works.” The clay is obtained from
the southwest part of 8. 27, the northeastern part of
S. 3, and the northwestern part of S. 34, in T. 3, R. 15
W. The clay appears in several beds, as shown by
the section below, which is taken from the notes of
Dr. Little.

Section near Pegram, Colbert Co.:

Pebbles of large size with sands..........-.+045 30 feet
White clay, one-eighth of a mile from mill....... 3 feet
Small gravel.......... . ered ese» wien wes dbeneee

White clay, sample No. 55, S......
Sand with large gravel overlying
Yellow clay, sample No. 56, S....
White: clayscsicsss, osewneds veaeeeem assure ees

Purple and black clay, sample No. 57, S.......... 10 feet
Gray clay, sample No. 58.... .. 2.50 cece eee ene 5 feet

110. GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

On land belonging to Mrs. C. Rhea, in the vicinity,
Dr. Little gives the section as follows:

Yellow loam sccccccc asec eerie ewei eee hacen 1 foot
Sandy clay (fire clay), sample No. 59.......... 5 feet

Of these clays Dr. Ries has analyzed and tested
Nos. 55, 56 and 57; No. 56 being classed by him among
the china clays, while the other two are ranked as fire
clays. The brick from this locality are used in Shef-
field for lining the furnaces, and they are also used
by the railroad. ,

In the Valley Regions Report, Part I, are given
three analyses of clays collected from this region near
the State line. These are as below:

Analyses of Clays from near Pegram.

1. 2. 3.
Combined water...... ass-s 8.250 6.827 7.085
BINCdiscreeee seeeenoeweas 66.122 7@.911 68.108
AMIMNdecis eywe sean eee 24.781 11.173 10.858
Ferric oxide.... ...... cee trace 3.449 14.471
Tl ao eke See Seas 99.153 99.360 100.522

(1.) A light colored clay with small lumps of gritty matter.
(2.) .A dark gray clay with black specks.or organic matter.
(3.) <A pinkish clay with white specks.

The light colored clay (1) above has been seen also
on the south side of Little Mountain, near the bottom
of the pebble hills, along the county line, a few miles
northeast of Frankfort. It shows here in an irregu-
larly stratified seam beneath the pebble bed. It is
quite pure and white, and has occasionally found use
as a whitewash, for which purpose it seems well
adapted.*

*Valley Regions, Part I, page 180.

CRETACEOUS FORMATION. 111

LAUDERDALE COUNTY.

The Tuscaloosa formation, which carries the clay
deposits, covers only the western half of Lauderdale,
the Subcarboniferous rocks forming the surface over
the eastern half. The clays are white, red and mot-
tled, and generally quite plastic. Mr. McCalley gives
some notes concerning them.

At the Tan-Yard Spring, in the N. HE. 4 of the

N. W. ¢ of S. 24, T. 1, R. 14 W., there is the following
section:

Section at Tan Yard Spring, Lauderdale Co.

Ferruginous CIUSUS isch es Ha, eee BER 1 foot
Clay, somewhat stained with jron, unctious and
plastic when wet.......602 seecee seacee 5 feet

This clay has been analyzed by Dr. Pickel, of the
University of Alabama, with the following results:

Analysis of Clay, Tan Yard Spring, Lauderdale Co.

SIMCAw cee Ee@rse ra See ECAR OREGON BeSienten 59.65
AUMINO vow, Caensere Reewedareen Kenatesareew 27.04
Ferric oxld@isaccccages svcaeundanwe, saeweoeaey 4.75

In the gullies, near the top of the divide between
Brush and Bluff creeks, in the southwest of the
northeast of S. 30, T. 1, R. 18 W., there are deposits
of white unctuous clay from seven to eight feet thick.*

Dr. Little’s notes supply some additional informa-
tion about! the clays of this county. Mr. Wm. J.
Beckwith has a clay deposit four and one-half miles
from Wright’s postoffice, on Brush Creek. It is
upon a high hill, and is five or six feet in thickness.
The clay is of a light yellow color, and is firm, fine
grained and smooth. It has been shipped north and

*Valley Regions, Part I, page 105.

112 GEOLOGICAL RELATIONS OF ALABAMA CLAYS.

sold for $12 a barrel, and can be delivered, barreled,
on the boat on the Tennessee river for $1 a barrel.

There is a red clay, suitable for paint, belonging to
the Sheffield Paint Company, near the county line,
six miles from Iuka, Miss. The bed is ten feet thick.
The white clay from Clingscale’s Mill, Miss., men-
tioned above in the extract from Dr. Hilgard’s report,
comes from localities near the State line, west of Lau-
derdale county.

In many parts of this county there are beds of
white pulverulent silica, which have occcasionally
found use. Thus at Florence the Mineral Paint and
Tripoli Company make a paint by mixing clay and
this fine silica together. At Waterloo, also, the same
white silica appears, as at Eastport, in Colbert coun-
ty. This material has been used in the manufacture
of glass at Pittsburg, Pa.

TERTIARY AND POST TERTIARY FORMATIONS.

The clays from these two formations have not yet
been specially investigated, the only representative
herein contained being the flint clay from Choctaw’
county. The material is spoken of under the head of
Fire Clays. There is a very great abundance of this
clay in the counties of Choctaw, Clarke, Conecuh,
etc., in the lower Claiborne or Buhrstone division of
the Tertiary. Over the greater part of the Coastal
Plain, in the river second bottom or Post Tertiary
formations, there is the best of the yellow loams
which. are suitable for the making of the ordinary
building brick. These loams correspond in age, ap-
proximately, to tthe Plisocene clays of the northern
states, which are so extensively used for the same
purposes. Besides these second bottom deposits,

TERTIARY AND POST TERTIARY FORMATIONS. 113

there are lens of pure plastic clays to be found in
many places interstratified with the prevailing sands
of the formation. Many of these clays have been re-
ceived and superficially tested, but it is the intention
to extend the present investigation over that part of
the state in the near future.

III

PRELIMINARY REPORT OF THE PHYS-
ICAL AND CHEMICAL PROP-
ERTIES OF THE CLAYS
OF ALABAMA,

By HEINRICH RIEs, PH. D.

The tests which are described below were made in part
on samples collected by the writer, and in part on sam-
ples collected by Prof. Smith. In the examination of the
different lots of clay an endeavor has been made to per-
form such tests on the materials as would tend to give
information of value to the practical clay worker.

This therefore includes the determination of the shrink-
age of the clay in drying and burning, the degree of its
plasticity, the color when burned at different tempera-
turcs, the temperature of incipient fusion, vitrification,
and viscosity, and other minor points.

In some cases it is possible to state what the possible
applications of a given clay are, but in many instances
any one clay is susceptible of being mixed with two or
three other clays and utilized in four or five different
ways. The main point therefore, is to point out the
properties of the deposits, so that the manufacturer may
find out more readily whether the State contains materi-.
als of the nature desired by him, and in what portion of
the State they are to be found.

It may be said in general that the results of the tests
made indicate the occurrence of a great diversity of clays
in the State, ranging from the more impure. and easily

116 DETAILED REPORT ON ALABAMA OLAYS.

fusible ones to the very refractory bauxites, which are
unaffected by high temperatures.

These investigations relate chiefly to those deposits
which have not yet been worked, with a view to aid the
development of Alabama’s clay resources; and conse-
quently little is said with regard to the industry already
established.

Where a number in parenthesis follows the name of
the locality, it refers to the number in the writer’s note
book, unless succeeded by the letter S in which case the
number is that on the:label furnished by Dr. Smith.

The clays examined by me have been classified below
as follows: China Clays; Fire Clays; Potters’ Clays; Brick
Clays; Miscellaneous Clays, and a few pages have been
added on the utilization of clays, i in the manufacture of
Portland Cement.

CHINA CLAYS.

China clays might include those used in the manufac-
ture of porcelain and white earthenware, and of ‘these,’
two grades are recognized, i. e., kaolins, or china clay
proper, and ball clays. The former possess little plastici-
ty, a low percentage of fusible impurities, are generally
highly refractory and burn to a pure white body. - Very
few kaolins can be put ‘on the market in the condition in
which they are mined, and most of them have to be
washed in order to eliminate impurities which would tend
either to discolor the clay or to render the texture far too
coarse. The tensile strength of kaolins may vary from 5
to 15 lbs..oreven reach 25 lbs., and the influence of this,
low strength is overcome by the addition of plastic ball
clay. . Iron is a very objectional impurity and should
not exceed | per cent. indeed the less of it the better.
Alkalies, if present-as silicates; are not wholly undesirable
for they serve as beneficial fluxes, but if contained in the

ios

. CHINA CLAYS. ° 117

-clay as sulphates they may cause blisters; especially if the
clay is heated too rapidly, and the same holds true of sul-
‘phate of lime or gypsum. Many washed kaolins ap-
proach very closely to the theoretical composition of kao-
linite, while others ‘even when washed may contain a
high percentage of total silica due to the presence of much
quartz and perhaps feldspar. If these two accessory min-
erals contain no iron they are harmless, especially if
finely divided, and the rational analysis of clay is known.

(See method of clay analysis.) The term kaolin is usu-
ally, and always should be restricted to white burning
clays of residual origin. They are in most instances
highly refractory, but they might also be of such compo-
sition as to bring about fusion at a low temperature, and
at the same time burn white. It is the absence of plastici-
ty in kaolins that necessitates the addition of ball clay,
but some manufacturers use only the ball clay, mixed
with quartz and feldspar for making porcelain. The
last two minerals are indispensable ingredients of white-
ware mixture, quartz being added for the purpose of pre-
venting excessive shrinkage, and feldspar on account of
its easy fusibility binding the mass together.

China clays should contain a low percentage of iron
oxide, in fact the less the better, for in burning this com-
pound tends to color the clay yellow or red. While the
percentage of iron oxide should be under 1 per cent.,
nevertheless many of the best china clays used contain
1.25 to 1.35 per cent. of iron oxide. This production of

a yellowish tint from such a quantity is prevented in two
' ways, first by adding a small amount of cobalt oxide to
the white-ware mixture, or secondly by taking advantage
of the fact that when the kiln, in which the ware is
burned, is heated to a high temperature the fire. tends to
act reducing, thereby changing the iron coloration from
yellow to bluish or bluish gray, and making it less no-
ticeable.

118 DETAILED REPORT ON ALABAMA CLAYS.

- Ball clays are used to mix with kaolin in the manu-
facture of porcelain and white-ware in order.to give plas-
ticity to the mass. . They should be as free from fluxing
impurities and mineral fragments as possible, and some-
times have to be washed. They generally burn nearly as
white as kaolin. Ball clays should have a good tensile
‘strength, not less than 60 lbs. to the square inch. They
are often dark brown or even black from the, presence of
abundant organic matter, but this color disappears on
heating. This organic matter exerts no other effect on
the clay than to increase the plasticity and air-shrinkage.

The Alabama clays included under this heading are
those which burn white or very nearly so at a moderate-
ly high temperature. Many of the specimens examined
are quite siliceous, and consequently exhibit a low
shrinkage in burning, while nearly all of them are of
sedimentary origin. a few, such as those associated with
the bauxite deposits, having an origin in common with
them.

In respect to their geologizal relations the china clays
here reported on come from three horizons, (1) the Cam-
brian and Silurian limestone, e. g. No. A. S. from Rock
Run; No. 190 from near Gadsden; and No. 205 from
near Kymulga, in Talladega Co. (2) the lower Sub-car-
boniferous cherty limestone; e. g. Nos. B. 8; 128, and 214,
from Willis’ Valley, between Fort Payne and the Georgia
state line. (8) the lower Cretaceous or Tuscaloosa forma-
tion, e. g. No. 38. 8; No. 85; No. 37.S from Chalk Bluff
and vicinity, Marion county: No. 37. S from Pearce’s
Mill, Marion county. and No. 56. S from Pegram in Col-
bert county.

Of the above, only the clays from ve Valley have
been regularly mined.

OHINA OLAYS. 119

‘CHINA CLAY.

FROM DYKE'S ORE BANK, ROCK RUN, CHEROKEE CO.
(NO. A. 8.)

A white, soft, gritty clay, which slakes easily in water.

The clay requires the addition of 30 per cent. of water
to make a workable mass, which is quite lean. Brick-
lets made from this shrunk 4 per cent. in drying and an
additional 12 per cent. in burning, making a total
shrinkage of 16 per cent.

The tensile strength of the air dried briquettes is low,
being only 9 lbs. per square inch on the average, with a
maximum of 12 lbs. per square inch.

Incipient fusion occurs at 2000 degrees, F. The clay
burns to a hard, marble like, dense body with a very
faint bluish tinge at 2100 degrees F.

The analysis of the clay is as given below.

Analysis of Ohina Clay, Rock Run, Cherokee Co. (No. A. 8.)

Billee scecaeeawage Ke eye ene KEReWeeeene DHes Ou 60.50
AIUMING, accciveses Se Soe GOONS ee See es 26.55
Water! caeses chs sada wae saa aed Gaede se 7.20
Ferric oxide ...... cece eec cece cee cee eeneereene 30
IMS as geese eco cS wd Raced Baw ye EAE Oe 90
Magnesia 2.2... 2505 cece ee cee eee ene ten eeeees .65
AIK@NES .uhcieece Sees edaess Aweeeed waedees ess 2.70
Moistures: :24544 SGkRe. Sov eaee> BWR we Koes ogee -70

99.50
Total MUXESi cacecked HEESEGEGEY CROLL HEE Se Ree 4.55
Specific gravity «..ccssers J1a EER EHORe FOO MEE 2.52

The rational composition is

Clay substance .....6.5 ceees eee reere eeeeeeeees 70.30
QUATEZ wee eee cece ee terre n teense settee teens 18.00
Feldspar .....-.eeesee ceeereee gee seen nee 22.20

120 DETAILED REPORT ON ALABAMA OLAYS.

This clay possesses an advantage in the density pro-
duced. by moderate burning but its high shrinkage would
have to be counteracted by the addition of more quartz.

CHINA CLAY.
FROM J. R. HUGHES, GADSDEN, ALA., (NO. 190.)

In the lump specimens this clay shows little evidence
of stratification. It is mostly white in color, and on the
average very fine grained 95 per cent of a lot of the sam-
ple sent passing through a 150 mesh sieve. There are
scattered through it occasional lumps of the halloysite, so
that the material would either have to be ground or
washed before shipping it to market. The latter course
would be more advisable as it at times shows yellow
patches of color. When thrown into water the clay
slakes moderately fast to flocculent particles. In wash-
ing it tends to stick on the sieve somewhat, and this
might cause trouble in pottery manufacture unless ground
quartz and feldspar were mixed with it in the proper pro-
portions.

In working it up with water 37.50 per cent of water
were required, and gave a mass of high plasticity.

The bricklets made from this had an airshrinking of
8 per cent.

In burning a noticeable property is the great density at-
tained at a comparatively low temperature, but this is al-
so accompanied by an additional though not great shrink-
age. Thus, at about 2130 F. the total shrinkage was
about 14 per cent. and the bricklet very dense; The color
was white. At 2250 F. the shrinkage was 15 per cent.
and the color white with a faint tinge of gray. At 2350
F. the shrinkage remained the same, and the color white

with a faint cream tinge. Incipient fusion began at
2250 F.

OHINA OLAYS. 121°

The clay fused at cone 27 in the Deville furnace.

The clay has to be heated: very slowly in ‘burning in
order to prevent cracking. :

The tensile strength of the briquettes was tried i in sev-
eral different ways.

One lot was made from clay ground. to pace through
a 20 mesh sieve, and these showed a tensile strength of
187 lbs. per square inch, the maximum being 154 lbs,

‘the variation in the different briquettes being 20 per
cent. A second lot was ground to pass through a 60
mesh sieve, and here the average strength was 138 Ibs.
per square inch, the maximum being 143 lbs. and the
variation 12 per cent.

A third lot was ground to pass through a 100 mesh
sieve and here the average tensile strength was 132 lbs.
per square inch with a maximum of 150 lbs. and a vari-
ation of 15 per cent.

The chemical analysis of this clay yielded:

Analysis of China Clay, J. R. Hughes. Gadsden. (No. 190.)

SUCH ca cckies <ezervers, eudaG rue eas ‘Veeeeecee 67.959
AIUMUDG: 25 cyriciccane GACERGE TY BESS ES gee 20.15
Ferric OX1de: wc seco bes VORSSCTS TTF E eee 1.00
DRDNG? as cre vsvarisveaverine icalisrataveusieceids ip acs eid eaiieey oe Pence ee 1.00
MA BTOBIG) isisacciinie es, lene aromie Sys iecese dh Side Weaaiere tO gusieme. tr.
PAIRSITES) via evcienprlie “eeisvele wie geeh aeareisia doNewss,, Qoabaretaoe ave 1.87
Wgnitions6¢ cagses eadewss wan Sawaee es ee eswisers 8.00
99.97
Total fluxes........sse0 ceaceee nalts ae Te se sieatatata 2.00

There are many points of.a desireable nature to be
found in this material, viz., its high plasticity, its great
density on burning, and te good tensile strength, all, ot
which would combine to make it a ball clay of good qual-
ity. The color on burning is not quite as white as could
be desired but no doubt washing would improve this.

122 DETAILED REPORT ON ALABAMA CLAYS.

CHINA CLAY.
TWO MILES N. OF KYMULGA, TALLADEGA CO. (NO. 205.)

A hard white clay, plainly stratified, due to the abun-
dance of many white mica scales arranged parallel with
the bedding: It is fine grained with a small amount of
fine grit. It slakes very slowly breaking into scaly frag-
ments. ‘

When ground to pass through a 100 mesh sieve it re-
quired 18 per cent. of water to mix it up, and give ita
mass which was only moderately plastic, owing to the
high amount of mica which it contains.

The air shrinkage of the clay when thus mixed is
5 per cent.

When burned to about 2200° F, the color was pure
white, and the total shrinkage 84 per cent., but incipi-
ent fusion had not been reached.

At 2350° F, the color was white, and the total
shrinkage 11 per cent.

In both cases the bricklets showed a tendency to
crack in burning.

Incipient fusion occurred at cone 27 in the Deville
furnace, but at. cone 30 vitrification was not complete.

If used by itself it would probably not be safe to use
the clay in its raw condition above 2250° without devel-
oping a yellowish tinge, although’ this migh not be no-
ticeable when ball clay and quartz and feldspar were
mixed. ’

The mica interfers with the tensile strength just as
it did with the plasticity, so that the former did not ex-
ceed 15 Ibs. to the square inch and varied between that
and 12 lbs. per square inch.

. CHINA CLAYS. 123

The chemical analysis of the material is as follows:

Analysis af China Clay near Kymulga, Talladega Co. (No. 205.)

Silla: -Sciks-diaesadow Rakake: SARs eeaeds enseee 50.45
ALUMINA 2. cece eee cee ee ee ce eee e ee Hennes 35.20
Ferric oxide. oi enscics: Shaecs saenicaes avcaas 80
Lime ....... pignshavay ieiengpetees algae Je stetevalae wmodien Rakeereere oe .60
Macnesla.-.cacsnce: aagaweeeees < selsisiammudd puacee o 62
AIKOHCS iis cre weesx gees ROS GdeCOEE Sees —-
Tenition. «scccvev waxerres epsavecd Busine deancesssenueaese 12.40

100.07
MOCAL URES ivevexccace ds cxvmraaravaniarnter reisiteteyireese salnstvereters 2.02

The clay would no doubt work for the manufacture
of white tile; or white earthenware, but could not be
used for porcelain without being washed.

(No. B. S.)
CHINA CLAY,

EUREKA MINE, DEKALB CO.

It is whitish clay, with little or no grit, and of re-
markable purity. In water it breaks up slowly to
small grains.

It took 33 per cent. of water to temper it, and gave
a lean mass, which shrunk 2 per cent. in drying, and
an additional 6 per cent. in burning, giving a_ total
shrinkage of 8 per cent. Air dried briquettes of the
clay had an average tensile strength of 25 pounds per
square inch, with a maximum of 27 pounds.

Incipient fusion occurs at 2300° F. vitrification at
2500° I’., and viscosity above 2700° F.

The clay burns to a very white, smooth body.

An analysis of the clay gave the following results:

124. DETAILED REPORT ON ALABAMA CLAYS.

Analysis of China Olay, Eureka Mines, DeKalb Oo. (No. B 8.)

BUCA csvowewisic cia: cee eeeCRs, MOVED Ec GrKEwS 47.00
AlUMINA Loe. ee cee eee te eee e rene cee eereees 38.75
WALLED cisiccsiaiere: appiele sie eceriies prermiie wip einaieney SEATS S 12.94
Clay Dase ...i cc. cece ne weer ee toeee erevcees 98.69
Ferric oxide ...... soccccecee eeescce sevecese fe 05
Lime... 2.0. cece cece cece ee cree ence serececes 70
Magnesia ......05 coer coecevne eee ee eS tr
BIKBWCS) sccisresiverccin, wees acertreres Semecseecne: wesealevecece tr

100.38
EDO Call SAUL OSsistesisesshensiiatocsiia Yo, Grbstesce’ layevouisunrane eG oveunvonedens 1.65

This clay approaches ‘closely to kaolinite in its
composition.

(No. 128.)
CHINA CLAY,

H. H. GRIFFIN, EUREKA MINE.

This is a white clay, which represents the best qual-
ity obtained in the mines of H. H. Griffin, four miles
northeast of Valley Head.

It is a very gritty, lean clay, which took 38.50 per
cent. of water to work it up. .

The air shrinkage was 34 per cent., and at 2250° F.
it had only shrunk 6 per cent., and barely showed
signs of incipient fusion. Vitrification takes place
at 2800° F. The analysis of a clay from this locality,
from what is known as the Eureka Mine, and made by
A. T. Brainard, was kindly furnished to ke writer by
Mr. Griffin. It is as follows:

''OHINA CLAYS. 125

Analysis of China Clay, Bureka Mines, DeKalb Oo.

Silica ..... he Knees D vteeseevveess exeuwe ex . 538.7300
AIGWING sieene 28000 0K0 BOER ELE ER REREN KOR KD 84.5390
Ferrous Oxidé-scasowr cesta 4sadaeree aeadied -8530
DATAGY toseicsiioas ssevousne queist sierdaseuevetecerey Vaupeesaliite Rabie? Sataieigs 4144
MAPNCSEY cocci iexecaigsors: aouisene cakaciswes nade eine .8420
Alkalies... 2.2.0.5 : erat tr
Sulphuric acid .2018
Phosphoric BCD s seis wow ew ees ace wii eke aa 0522
MENILON saucer: wuensaes. 539 bas weEER oR eEes 12.28
102.4124
TOCA] MGKES.. crsncceie: aseuerecs ie ceaseversveneies avs pcvasienaiteciaiisiatete 1.609

The following analysis of sample collected by writ-
er from the mines in 1897, gave the following:

Analysis of China Olay, Eureka Mines, DeKalb Oo. (No. 128.)

Silica ...cccae cccnees cee ad Maree, Gees 82.11
Alumina .......... ag apupsecsuene Bh ca eee RTS Seb rcienein coeds: 11.41
Ferric oxide..... 22.62 oe acasauaadeusue caimae rete eck? Yoasneds 1.40
DAME) seca ecsce aegis eerie ésdteltalted suite eedierey Sechcevasiererece aajaeeaie tr
Magnesia ....0.5 cseeesscee « pee e eee e eee weeeee 661
Alkalies cccsescesn aco Bi iE wapetepeuss seveiaseres, 1.80
Ignition ........ o ORTRARES GEES eesesiEaes 4.001
= 4.001
101.382
Total NUKEM: ..0ukieers ceaeesnn saacsd seaveere 8186

The rational analysis gave

Clay substance .....0. ceeceeee coevvee = eee 20.20

© QUATTZ coc cee cee Sew aa ne, Baad yap Aishannieas Joneses 69.20
Feldspar ...-...+++ «++ OR ae ee a ee 10.40
99.80

The feldspar percentage influences the fusibility of
this clay, and the difference in the two quantitative
analyses is due to the latter having been made on an
unwashed sample. !

126 DETAILED REPORT ON ALABAMA CLAYS.

(No. 214.)
CHINA CLAY,

FROM F. Y. ANDERSON, NEAR FORT PAYNE, DEKALB CO.

This clay is rather sandy in its nature, unless
ground extremely fine, the granular character being
due partly to the halloysite which it contains.

It slakes very slowly and incompletely, and took in
its air dried condition 30 per cent. of water to work
it up. i

The air shrinkage of the bricklets was 7 per cent. At
cone 27 in the Deville furance, it was white and show-’
ed traces of incipient fusion. At about 2350° F., it
burned white without a trace of yellowish color, and
with a total shrinkage of 11 per cent.

It is evident that this material could be used in the
manufacture of white ware. It would, however, take
much grinding to develop its plasticity fully.

The tensile strength was from 60 to 65 pounds per
square inch when the material was ground to 60 mesh,
and the briquettes are very constant in strength.
With finer grinding the tensile strength would very
probably increase.

The chemical analysis yielded:

Analysis of China Clay, F. Y. Anderson, DeKalb Oo. (No. 214.)

Silica ..... Mtiee Acne AaeeE: Beaiciewie 53.50
ALUMINA soc, aus REA BEAT RES SEK Bone ciew: 34.45
REPEL) OR LAE os, siescinecau Gayla levatianisn “bidcisneseunleiandea eG sacs hieae: 21
LE akine Sanneenn Disbice ee Aewenaanwen gen eKan -30
Maenesiss awaasieiic aintadeieye- Tpkersitenvs eal agienele trace
MIRSNOP 003 eee beese KeeEe Bemew axOEN eT 21
AZBNIOiewee Suwa es 8S HEENRER Ktnewnime we eee 18.20

101.87

‘ CHINA OLAYS. 127

(No. 38 8.)
CHINA CLAY.

J.J. MITCHELLS, CHALK BLUFF, MARION CO.

Pure white, fine: grained clay, brittle when dry,
and with conchoidal fracture. It slakes easily in
water, all of it passing through a 60 mesh sieve and
most of it through a 100 mesh one.

The clay ground to pass through a 30 mesh sieve,
and mixed with 24 per cent. of water, gave a lean
mass whose air shrinkage was 4 per cent. and an addi-.
tional shrinkage of 3 per cent. took place in burning,
giving a total of 7 per cent.

Air dried briquettes of the clay gave the usual low
tensile strength of kaolin, the average being 15 pounds
per square inch, with a maximum of 17 pounds per
square inch.

Incipient fusion occurs at 2300° F., vitrification
at 2600° F., annd viscosity at 2700° F.

The clay burns to a clear white body. Its composi-
tion is as follows: (No. 1 being by H. Ries and No. 2
by W. B. Phillips. No. 3 is the composition of. pure
kaolin given for comparison. )

Analyses of China Clay, Chalk Bluff, Marion Oo.

1 2 3

SING. osaeda Meeew Ge sunny 47.25 47.20 46.30
Alumina ...... ceeee see 36.50 37.76 39.80
Wate w2.6 ctease Siteees 13.35 14,24 13.90
Ferric oxide ...... «s-seee 2.56 tr
DAMG. eececcce, wssiia ) catsueneress tr tr
Magnesia ..... wees saeee tr tr
Moisture ..... ..20- ceeee 50 tr

100.16 99.20 100.00
Total: fluxes. Cis as cacy wie easeweeeee: wwe des 2.56

Specific gravity ....... cceeeecsceaee seeneveres 2.44

128 DETAILED REPORT ON ALABAMA CLAYS.

(No. 85.)
CHINA CLAY.
CHALK BLUFF, MARION CO.

This clay which occurs on the ,property of Mrs.
Nelson is a smooth, white, fine grained clay with a
conchoidal fracture. It slakes easily into angular
grains. It is very lean, and requires 33 per cent. of
water to mix it up. The tensile strength is also very
low, being only 15 pounds per square inch. The air
shrinkage is 4 er cent.

At 2200° Fahr. the total shrinkage was 10 per cent.
At. 2350°, it was 15 per cent., and the bricklet incipi-
ently fused, with a yellowish white color.

At 2500°, the total shrinkage was 18 per cent. The
color was yellow. Vitrificaton occurred at 2700° F.

In the Deville furnace, at cone 27, the clay was
nearly viscous.

No analysis was made of this clay.

(No. 37 8.)
CHINA CLAY.

BRIGGS FREDERICK, NEAR CHALK BLUFF, MARION CO.

This was a fine grained clay, 90 per cent. of it pas-
sing through a 60 mesh sieve. The clay took 25 pe
cent. of water to be worked up, and even then was
lean and granular, fine grinding being necessary to
develop proper plasticity.

The air shrinkage was 24 per cent. and the fire
shrinkage was the same, giving a total shrinkage of
5 per cent. in the case of a sample ground to pass
through a 30 mesh sieve.

CHINA CLAYS, 129

The air dried briquettes showed an average tensile
strength of 14 pounds per square inch, and a maxi-
mum of 16 pounds.

Incipient fusion occurs at 2300° F., vitrification at
2500° F., and viscosity above 2700° F. The clay
burns to a white but somewhat porous body.

Its composition is as follows:

Analysis of China Clay, Briggs Frederick, Marion Oo. (No. 37, S.)

Ligscie VISA dada doe SEEDER ed Wedae epee 65.49
ANUMIRG 5 sss aeeinjoea saree Mies MANY Stanctetallecece ae 24.84
WRG 5 asics. havea aiden ay: -caetere aoe NR ah resieceaplace ees 7.50
MeLEIC, OXIME sires scasacda 64 titalsiqe. sare don earoamace tr.
LMG ise wade sa: BOGE SEES “caiisied aaddoweinwes 1.26
Magnesia iccaae. wages te Soca maauade dese ews tr.
AlkalieS acer cey WEN WAR es “atau dove siee ahdoawe tr.
Moisture. vi44 sexe. a vetugaad: wueerecuedea eibai 4 .30
99.37

Total MUXES sicsowie ceeds suwave ee Gcpelelewncies 1.26
Specific gravity........ .ccc cece ccceececce 1.76

This clay is very low in iron, and the small per-
centage of lime is no detriment.

(No. 36 8.)
CHINA CLAY.

PEARCE’S MILL, MARION CO.

A hard, porous, coarse grained, gritty clay, which
in water breaks up slowly into angular fragments,
each of which in turn keeps splitting.

Twenty-five per cent. of water was required to work
it up, but it is very lean. The air shrinkage was 3
per cent. and an additional 12 per cent. in burning,
making a total of 15 per cent. ae

The tensile strength of air dried briquettes. varied
on the average 12-14 pounds per square inch with a
maximum of 20 pounds per square inch. -

130 DETAILED REPORT ON ALABAMA CLAYS.

Incipient fusion occurred at 2300° F., vitrification
at 2500° F., and viscosity at over 2700° F.

The clay burns at 2300° F. to a very white body.

The analysis of it yielded.

Analysis of China Clay, Pearce’s Mill, Marion Co. (Wo. 36, S.)

Silica (combined) .....+4. cuscceeres seveccvace 38.60
Alumina... 2.0.65 cece teen eee ee ceeeeee ceeees 32.50
Water... cece cee cece ee cree e cee cece reencees 11.05
Clay DAS@ ..e cece cece teeter eee n ee cece eeenee 82.15
Silica (free)... 6... cece ee cee eee tee ce ee ce eee 17.68
Ferric oxide. ....... ceccereeceee cere recnecenes .20
LAMG. 6 ci nwiee Shave We dey Beige eee owed) aeons tr.
Magnesia... .. cee ee cece reece cert eee ene ceeee tr.
P:005¢:) 6 (-)- tr.
MOStUre’s eat vas bie wass waversr sr te SS oreuneieretersas whet .20
100.03
Total Muxes scicvcgaw aagreie ae Hews oie .20
Specific gravity........ seevecee svvcsesccerees 2.33

With washing, this clay would probably be well
adapted to the manufacture of the highest grades of
pottery. It contains less fusible impurities than most
of the kaolins used in this country, and the probabili-
ties are that if the deposit were constant in its char-
acter it might not require washing.

(No. 56 8.)
CHINA CLAY.

PEGRAM, COLBERT CO.

A fine grained, whitish, homogeneous but not very
dense clay with a smooth fracture.

In water it slakes slowly to grains under a sixtieth
of an inch (1-60 in.)

Thirty per cent. of water was required to make a
workable mass, which to the feel was quite lean.
The air shrinkage of bricklets made from it was 7 per

ax OHINA OLAYS. 131

cent., and 4 per cent. in burning, making a total of
11 per cent.

The tensile serength of the air dried briquette was
quite low, being 40. pounds per square inch on the
average, with a maximum of 53 pounds per square
inch.

Incipient fusion occurs at 2200° F., vitrification at
2400° F., and viscosity at 2600° F.

The clay burns to a white body which is hard aud
dense, the following is the analysis of the clay.

Analysis of China Olay, Pegram, Oolbert Oo. (No. 56, S.)

Motel “SUC oss sise.s.66 vie cashew SOS) ae STR BES Gerenertoerd 64.90
ATU A eae Gvsvecar” deiecshersreveud weRs Gronsuoreeiinne gous.” secaveriueiiale 25.25
SW BE GE aa. lec cxrauty A wsdub teecauia Ap! corsiia ore alles Gud Gabaesiaiecae aceite 2 8.00
MIOTSEUTE aii acc don sexeiedwied ts shxoral wien mite jose ka tone hos ay ariete an 90
MOrric 1OK(Ge via aisge- 4 Waa wpacecnlicatite Sela ahere ited ee trace
CAMO S becca eae isaac Sahu te es es Sere SS trace
Magneslawieicie ees ateun kins, adepemee warns wee trace

99.05
Fee si’ a...... See Dee See err 34.40
Specific. gravity cscseois os xiidiwedasres: soko 2.35

The material is to be looked upon as a white-ware
elay of good grade, from which the sand could be re-
moved by washing if necessary. There are practical-
ly no published analysis with which this agrees very
closely, but a comparion is not necessary as the purity
of the material is self evident.

FIRE CLAYS

The term fire-clay is applied to those clays which
will resist a high temperature without fusing.

Fire clays are of two kinds, flint clays and plastic
clays.

The flint clays generally approach kaolinite in com-
position, but have no plasticity, or at the most a very:

132 DETAILED REPORT ON ALABAMA CLAYS.

slight degree of it. They are generally of a highly
refractory nature, their fusing point being commonly
above 2700° F. and their shrinkage in drying and
burning is extremely low. They therefore make an
excellent grog to add to the more plastic clays for the
purpose of reducing their shrinkage. Flint clays
have thus far not been found in Alabama, except
in Conecuh, Choctaw, Washington, Clarke and
Monroe counties.

Plastic fire clays are widely distributed and are
especially abundant in the Coal Measures of many
states, but they may also ocsur in the Cretaceous
and Tertiary formations. Those of the Carbonifer-
ous are often of a shaly nature and to be ground be-
fore their plasticity can be brought forth.

The requisite qualities of a fire clay vary some-
what according to the use to which it is to be put, and
it is still a disputed point, just what temperature the
fusion point of a clay should exceed in order to be
classed as a refractory one. As it now stands, many
American clays are unfortunately and erroneously
classed as fire clays which can not withstand a tem-
erature of more than 2300° or 2400° F. Many of the
New Jersey fire clays require a temperature of from
2500° to 2600° F. to burn them.* The fire clays of
Missouri fuse at from 2400° to above 2700".

No arbitrary line can be drawn between refractory
and semi-refractory clays, but if such a division were
made it would seem advisable not to call any clay re-
fractory which is affected by a temperature of less
than 2700° F. Many of the Alabama fire clays con-
form to this definition.

While it is desirable that fire clays should posses
good plasticity and low shrinkage; the main point is
their refractoriness. It may be said in general that

FIRE CLAYS. 133

the fusible impurities of a fire clay should not exceed
33 or 4 per cent., but these limits may be extended
somewhat in either direction depending upon the
nature of the flux and whether the clay is fine or
coarse grained.

The shrinkage of a fire clay in burning may often be
counteracted by the addition of grog, i. e. sand,
ground fire brick, or similar substances.Fire clays
which are too fat and plastic are likely to crack in
burning, but at the same time they give a dense body.
It is desirable that any burned clay or grog which is
mixed with the raw material should have previously
been burned as dense as possible. Fine grains of pow-
dered grog permits the brick to shrink more in burning
than the course and bricks with the latter generally
stand changes of temperature better. Next to burn-
ed clay, quartz is perhaps the most important grog,
and flint clay serves a simila” purpose.

If a fire brick made only of clay and clay grogs
still shrinks when placed in the furnace, sharp quartz
grains should be added, as they have a tendency to
expand on repeated heating. Fine grained quartz
sand should in no case be added if the brick is to be
exposed to high temperatures, for in such cases it
tends to flux the clay in burning, furthermore the
addition of coarse quartz must also be within limits
for if in too large quantity the quartz grains loosen the
brick -by their expansion. A good fire brick is some-
times made by mixing a non-plastic refractory clay
with a very plastic dense burning, semi-refractory
one.

No fixed rules can be laid down to govern the
selection and valuation of a fire clay for the reason
that the use to which it, is to. be put determines its
qualities to a large extent. All fire clays should

"134 DETAILED REPOR1 ON ALABAMA CLAYS.

resist a high temperature. Some are used in situa-
tions requiring resistance to heat and these must be
coarse grained. Others when burned into bricks
must resist corrosion and consequently should burn
to a dense product, as in the case of glass pot clays.

Fire bricks.—These should show a resistance to
high temperatures, and also the fluxing action of
ashes from the fuel, which contain carbonates, sul
phates, and phosphates of the alkalies and alkaline
earths. In addition they should withstand the cor-
rosive action of fused metallic slags, alkalies, and
glasses.

The density of the fire brick is often of great im-
poitance especially where it.is to resist the corrosive
action of molten material. The fat plastic clays are
those which usually burn to the most dense body, but
in doing so they frequently crack to such an extent
that grog has to be added to them.

Porous, coarse grained bricks on the other hand
stand heat better.

The fire-clays below reported on come from four
geological horizons, viz., (1) The Cambrian and Sil-
urian limestone formations of the Coosa Valley regi-
on; No. 191 from Peaceburg, Calhoun county; No. 127
Stevens, from Oxanna, Calhoun Co.; the refractory
clays of Rock Run, Cherokee Co.; and the bauxites
from the same locality. (2) The cherty limestones
of the lower Subcarboniferous formation of Wills’
Valley; No. 117 and 116 from the Montague mines,
and No. 119 from near Valley Head in DeKalb
county. (8) The Tuscaloosa formation of the ower
Cretaceous, No. 112 from Bibbville, and No. 111
from Woodstock in Bibb county; No. B from near
Hull’s Station, and No. 118 from near Tuscaloosa in
Tuscaloosa county; Nos. 1 and 2 from Pearce’s Mills

FIRE .CLAYS. 135

in Marion county and No. 57 8. from Pegram in Col-
bert county. (4) The lower Tertiary formation, No.
C 8 from Choctaw county. Of these only the clays
from Bibbville and Woodstock have been regularly
mined.

(No. 191.)
FIRE CLAY.

FROM PEACEBURG, NEAR ANNISTON.

A grayish white clay of very fine grain, and contain-
ing a noticeable amount of very fine mica scales. In
water it slakes moderately fast.

Twenty-five per cent. of water was required to
work it up, and the resulting mass was rather lean,
and had a somewhat flaky structure, which interfer-
red with the development of the plasticity.

Bricklets made from the mixture had air shrinkage
of 5 per cent.

When burned to about 2100° F. the total shrinkage
amounted to 10 per cent, the clay was white with a
faint tinge of yellow and the brick was still very por-
ous. At about 2250° F. incipient fusion has barely
been reached, wth a total shrinkage of 13 per cent.,
the color being white tinged to a noticeable extent
with yellow. At about 2300° F. the bricklet burned
cream color, was incipiently fused, and the total
shrinkage amounted to 15 per cent.

In the Deville furnace the clay vitrified at cone 30,
but did not lose its shape.

Owing to the leanness the tensile strength was very
low, and ranged from 20 to 25 pounds per square inch.

The: chemical analysis of the clay gave:

136 DETAILED REPORT ON ALABAMA CLAYS.

Analysis of fire clay, Peaceburg. Cathoun Oo. (No. 191.)

Silica... ccc cece cece eee cece ee cre enrce 51.90
Alumina... .....c cee cece eens cence eee nae eee 35.00
Ferric oxide...... ssacvseccccce secre vessceees -99
Lime... cc crcccce ceccee weawens sensereccsenee 23
Magnesia......24 seccccceee seeneee ceeeevsecre 10
AIRES. co:s de cise nevi en Giese TRATES Oe 8 55
Ignition. .....02 sccccceren secnsrece eoenscnens 11.30
99.87

Lotal Duxescis- cae nai GA ee Gs Re eee eae lan 1.87

The low plasticity of this clay would probably inter-
fere with its being used alone, but owing to its re-
fractory nature and the light color developed in burn-
ing it could no doubt find use as an ingredient of
other clay mixtures.

(No. 127 of Mr. Stevens. )
FIRE CLAY.

FROM OXANNA, CALHOUN COUNTY.

This is a coarse and sandy clay, which mixes up to
a lean mass with only 16 per cent. of water. The
tensile strength is very low, being on the average of
9 to 10 pounds per square inch, and the air shrinkage
is 2 per cent.

The following is the behavior of the clay at suc-
cessively higher temperatures.

At 2200° F. the color was grey white.

At 2250° F. shrinkage 3 per cent., color buff.

At 2300° F. shrinkage and color same.

At 2400° F. shrinkage 3 per cent., color buff, show-
ing specks of ferric oxide.

At 2500° F. the shrinkage was only 2 per cent., hav-
ing undergone a slight swelling owing to the very
high quartz percentage. Incipient fusion had not

FIRE OLAYS. 137

occurred up to this point. The following is the
analysis of this clay.

Analysis of Fire Clay, Oxanna, Calhoun Co. (No. 127, Stevens).

AIUMING. coi: cca tewicms: sities ewes eure es 9.75
Perrie OXd@.sccecuc aseacvewse aeeveeesa neways 69
LIM a a ered segiieias.'s Siersuaieaes: erg Bredeia e Bavereid we miereves 70
MAZNeSiOeiccovsss sawagietuees eeews se Seiceew Aves 14
Tenltionccces acaueaesed setae sssodavcaceoes oy -4.10
oe ane

99.59

Total fluxes

REFRACTORY CLAYS

OF ROCK RUN, CHEROKEE COUNTY.

Associated with the bauxites at Rock Run are a
number of clays, most of them of fine grained texture,
but some showing small quantities of grit, and which
vary in color from pure white to mottled ones, which
at times contain an appreciable percentage of sand.
Samples of these clays from six different locations
have been tested, they come from what are known as
the Dykes old Iron Ore Mine and the Dykes Bauxite
Mine, on the property of the Rock Run Iron Mining
Co. in Cherokee county.

No. 1. is on the north side of the iron mine reserva-
tion at the extreme western end; No. 2 and 3 are from
the same side of the pit, but at points 125 and 200
feet farther east respectively; No. 4 is from the west-
ern end of the Bauxite pit and on the north side of
the entrance to it; No.5 is on the north side of
the same pit and No. 6 at the eastern end of it.

Nos. 1, 2, 3, each show a face 15 to 20 feet in height,
and are of probably greater thickness. No. 4 is look-
ed upon as a very low grade of bauxite.

138 DETAILED REPORT ON ALABAMA CLAYS.

The following tests mere made upon. these samples:

No. 1. This is a fine grained white clay, with a
splintery fracture, showing iron stains along the joint
cracks and other planes or fracture, but none in the
interior of the mass. It slakes quickly but not com-
pletely into angular fragments. In mixing it up, 32
per cent. of water was required and the resulting
mass was lean and granular. It had been previously
passed through a 30 mesh sieve, and it ground to a
finer, mesh would, no doubt, be more piastic. The
lean granular character gives it a very low tensile
strength amounting to not over 6 pounds.

The air shrinkage of the clay was 4 per cent. at
about 22004 F., the total shrinkage was 9 per cent;
and at about 2300°, 18 pr cent., at about 2500°, the
total shrinkage was 21.50 per cent, and the color of
the burned bricklet was still white.

When tested in the Deville furnace at cone 30 the
form of the clay still remained sharp, and it was
white in color, but showed signs of incipient fusion.

The compositicn of the clay is as follows:

Analysis of Fire Clay, Rock Run, Oherokee Co. (No. 1.)

Sillea sob gio Br aatinn AAS tae Wench eaw wa wee 47.60
AIUMING)) ess retis, Gace aisidiehd - eareeele a Beseaeig dine 36.70
Ferrie: oxidey..iscssad 4 iceaadeneee saa nes were a Os 1.10
VAMC eieiiisers g- eahe PERS FER DE EADAEEN Reads onsen 1.30
Magnesia 5 sii sie ae Svein Rineee secdsee) (ocecdiaiautveedv. aovenwae trace
AM AII Gs ge Gog 24 sez davis ~yasmesingannis 4 yakeenneaouk: (andes trace
Tgnitiont: <cricis- 24 Samad: tecaewe i BRRoS RWlew eer 14,20
100.90
Total @Uxes sade. saaw aes. aidg see eeenwds %.40

These tests indicate that the clay is quite refrac-
tory, and its burning to a white color would permit its
being used for products having a white body. The
high shrinkage is somewhat against it, but this could

FIRE CLAYS. 139

be counteracted to a large extent by the addition of
quartz and it would also be necessary to mix it with
some plastic clay, if it was to be molded when wet.

No. 2. This is similar to No. 1 in its color and tex-
ture. It is however much more plastic than the
other although it only required 31.25 per cent. of
water to mix it,thetensile strength however is very
low, and in this case bears no relation to the plastic-
ity, the air shrinkage of the clay is 3 per cent; at
about 2200° F., the total shrinkage was 10 per cent.
and the bricklet was still absorbent although incipient
fusion had just begun, while the color was yellowish
white; at about 2250° F., the total shrinkage was 14
per cent., the bricklets had an absorption of about 5.7
per cent. and the color still a yellowish white. At
about 2300° F. the total shrinkage was 16 per cent.,
the absorption only 2 per cent. while its color was a
very faint yellowish gray; the total shrinkage was 17
per cent. at 2400° F., and the bricklet which appeared
nearly vitrified, was gray in color.

In the Deville furnace at cone 30, the form of the
clay was still perfectly sharp, and while it was thor-
oughly vitrified it showed no evidence of becoming
viscous. ;

The rational composition of the clay was:

Clay substance........06 sscceaee soenen vencees 94.54
QAP TS icici aireareeracteay eee ciicecatest ayes «anew eves eltacctiaus ve iacaaie 5.80
FROrric: 0X1 @ si, scanie-ai ain, athesvareparsiter ee lenmparaahenansean sargre cee 26

No. 3. This is likewise a white clay but one con-
taining much fine grit, not very porous, and slaking
quickly to a powder. It is also a very plastic clay,
and took 36.50 per cent. of water to work up, but the
tensile strength again is very low, being not over 5
pounds. The air shrinkage was 3 per cent.; at about

140 DETAILED REPORT ON ALABAMA CLAYS.

2200° F., the total shrinkage was 12 per cent., and the
bricklet white, with an absorption of 7.20 per cent.
At about 2250° F. the total shrinkage was 13 per cent.
and the bricklet, which had an absorption of 6.3 per
cent. was white with a very faint tinge of yellow. At
about 2300° F., the total shrinkage amounts to 15.5
per cent., the color of the bricklet white with a mere
shade of gray, and the absorption of it had decreased
to 1.3 percent. The total shrinkage at about 2500° F.
was 17.5 per cent. and vitrification had occurred, the
bricklet being whitish in color.

In the Deville furnace at cone 30, the form of the
clay pyramid was still erect, and while the clay was
thoroughly vitrified the angles were still sharp and
color whitish. The composition is:

Analysis of Fire Clay, Rock Run, Cherokee Co. (No. 8).

LIT CB sacs cevoeten aia doug casticdecus ed ab giacla yeh aries savaatontexase Vere @uaseienavatotan 72.20
AWN saree ceaeecena agheuas ge Sees cmewenern 22.04
Pernice OxlG@sceegi neve epevadeere edeesare «ened 16
LMG es isciveciis akices vie camera es “Kewanee 50
Magnieslaises y ix wawlngs, 4 4hc4. shy vesavernsorsse wresa rs avecscartve .40
AVE ACS eptnaied: ches desdecevecinaces” avevoraroroe ee dhe wcsenains 60
TEMION sts ceres or, avetevommayite Pwdegior geikceeay antec 5.80
101.70

BANG casacarcich eigsenaeelinals. ee aigiwiwy “Ate eegesky eidseanee Qavets 34.52
Total Muxes: sus vivsarinwss sascacaredaw -aetades 1.66

No. 4. This clay as has already been stated is a
low grade bauxite, it is white in color with a slight
yellowish tinge and portions of it show a pisolitic
structure. It slakes quickly. 31.35 per cent. of wat-
er were required to work it up and even then the mud
was extremely granular and very lean, and the air
dried briquetts had a tensile strength of only 5
pounds. The air shrinkage was 5 per cent. At2250°
F. the total shrinkage was 14 per cent., the bricklets

FIRE OLAYS. 141

very porous, of a white color with a mere tinge of yel-
low. At 2400° F. the total shrinkage was 15 per cent.
In the Deville furnace at cone 27, the clay still re-
mained entirely unaffected, but the color was grayish,
and the total shrinkage up to this point amounted to
26 per cent.
The composition of the clay is:

Analysis of Fire Clay, Rock Run, Oherokee Oo., No. 4.

BU ccna eis BELEN We AY REESE KOR KOAOY Pek eEaRS 17.70
ANMUNG sé ois ahoweed ads seen Oe aKe weeereT 59.46
Ferrie: O21dG@iic0 23 cctsana seeeweaed 445 445G4en06 36
Tenitions sass: egies Meese ee sana Qanioa eaaaveie 22.06
99.58

OCA (AUK saisid: Secocace aa: Sy tala ieas-. avai rerq avanersrsee -36

No. 5. This is a soft whitish, easy slaking clay,
but a very porous one which absorbs 40 per cent. of
water in working it up, and even then gave a very
lean mass, whose tensile strength, when made into
briquettes and air dried, was only 5 pounds per square
inch. The air shrinkage is 4 per cent, and at about
2250° F. the total shrinkage was 17 per cent., but the
bricklets, whose color was yellow, were still very
porous and could be scratched by a knife without
much difficulty; at 2400° F., the shrinkage showed
a total of 22 per cent. and incipient fusion began; at
2500° F., the total shrinkage was 23 per cent., the
brick was still porous and faintly yellowish white.

In the Deville furnace at cone 30, the clay had
burned dense, was incipiently fused, but otherwise
unaffected, its color was a grayish white and the total
shrinkage amounted to 34 per cent., which is really
not surprising when we consider the high amount of

142 DETAILED REPORT ON ALABAMA CLAYS.

combined water that the clay shows, for it is evident-
ly a low grade bauxite like the preceding one.
The composition is:

Analysis of Fire Clay, Rock Run, Cherokee Co., No. 5.

Silla yeswen SSeiNe NOE KEEN WOsS EKO ew ees we 31.20
ALUMING ois Gece es sees Gens s Cees Sees 44.28
Ferric oxide....... cess cece eee ee cece r eee nene 1.45
DAMGs.. ee ah tes Sep See Wareccereveies Qieee Sea RARE S 8 1.00
Magnesia... wc c cece ee cece eee e ne tere enecees 20
TPMT OD sprees o's tes eie aks Sle ee BUR Jee aidteaiw. ite mia © 22.60
100.73

2.65

Total fluxeS.... wc cence wees cece cctnanees

This clay is evidently a mixture of clay and bauxite,
as can be seen from the high shrinkage and large per-
centage of combined water.

No. 6. The color of this clay is yellow, and it is
fine grained but not hard, and shows numerous slick-
enside surfaces. In slaking it breaks up easily but
slakes completely to powder only after long immer-
sion in water. The clay is very lean, and requires as
much water as the preceding to mix it up; the tensile
strength is also very low being under 5'pounds. The
air shrinkage is 2 per cent., the total shrinkage at
2200° F. is 8 per cent.; at 2250° F. it is 12 per cent.;
at 2400° F. it is 18 per cent; at 3500° F. it is 15 per
cent.; at 2600° F. it is 20 per cent., and the bricklet
was still very absorbent.

In the Deville furnace at cone 27, the clay had burn-
ed dense, but still preserved its form with ‘sharp edges
and showed a total shrinkage up to this point of 35
per cent.

The composition of the clay is as follows:

Analysis of Fire Clay, Rock Run, Cherokee Co., No. 6.

BiMCh cocina wrotew ising eaiiea viene. Sewieh elisa Gene 34.60
Blan E bybeddacs Heees Cone e ¥ bed eReM % AAD 45.80
Werric Oxlds 005: sseeisas eoekedecge euderesesces 52
ISDIEODs cas Ruweer KES KOREES £O0 ee eee See RE 20.00

100.92

FIRE CLAYS. 143

REFACTORY BAUXITES.

ROCK RUN, CHEROKEE COUNTY.

In addition to these bauxitic clays, six samples of
bauxite were also tested chiefly to determine their
refractoriness and their shrinkage in burning, the
method adopted with most of them being to grind up
the specimen, so that it would pass through either a
20 or a 30 mesh sieve, the particles which did not pass
through being also retained. Several mixtures of the
coarse and fine material were made. The mass pro-
duced in every instance by mixing it with water was
extremely low in its plasticity, and lacked greatly in
tensile strength, the latter in every instance being
not more than 2 or 3 pounds per square inch.

In many cases, the bauxite showed so little tenacity
and was so little affected by the heat that bricks
which had been burned at a temperature of 2600° F.
were easily rubbed apart with the fingers. Another
point to be noticed is the enormous shrinkage which
all of the specimens exhibited, the air shrinkage, how-
ever, being very low.

No. 1. This was powdered and passed through a
30-mesh sieve, and on working up gave a very lean
mass, which required 24 per cent. of water. The air
shrinkage was 3 per cent. and at 2400° F. the total
shrinkage was 11 per cent, while the bricklet was very
porous and white. At 2500° F. the bricklet had not
shrunk any more but the color had become reddish.

In the Deville furnace at cone 30, the bauxite was
totally unaffected although it had become somewhat
dense, and showed a shrinkage of 23 per cent. The
composition was:

144 DETAILED REPORT ON ALABAMA CLAYS.

Analysis of Bauxite, Rock Run, Cherokee Co., No. 1.

SUCH cctv Sivek Ses Asse Reeeie Js ae eee 8.80
AMAIA IT Bi oye Gass” -ejaoueray Uiye Bee ce eet AS Bhan aesbeh ons 61.64
Ferric. Ox1d@ i. ices ce cces ware eee tiew SS Seem 1.10
TANG ies sic esi seeis as vseselde eS esepce: ose onievananie Sepsis eh ce trace
MASHOSID esis eee We) WR See eee ee trace
TEMItlOMs gies, So ecavavepeionnss We da Sie! sete Sraspe dese 8 vee wie ener. 29.97

100.51

No. 2. Two mixtures were made of this, viz: a.
which was 50 per cent. of grains between 15 and
20-mesh, and 50 per cent. smaller than 20-mesh. The
pricklet made from this showed a total shrinkage of
12 per cent. at 2400° F., while at 2600° F., the shrink-
‘age was 14 per cent. and the bricklet was so friable
that it could be easily rubbed apart.

b. The bauxite was ground and passed through a
30-mesh sieve. In this condition it took 25 per cent.
of water to mix it up, and made a very lean paste.
The shrinkage of the: bricklets made from this was
about 10 per cent at 2250° F., they were very porous,
soft, and of a slight yellowish tint; at about 2400° F.
the total shrinkage was 15 per cent. and at 2600° F.
amounted to 17 per cent., but the bricklet was still
scratched by a knife without much difficulty. In the
Deville furnace the bauxite was still uneffected at
cone 30, but showed a total shrinkage of 27 per cent.

Its composition is:

Analysis of Bauwite, Rock Run, Cherokee Oo., No. 2.

SLC iasstsisnar aanstaes wiedithce Bicets ele ties (aloniaeiea.oa scat 18.30
AVWOMONM ea siss Ede we Ge ee reede Spee ee wieleeaes - §439
Ferric! 0x1d@s wsiewee aasaaniee ees esiewe sad wareies 1.36
Wenitlons csicace secede sows aeeees sews err eect 27.60

101.65

72. (No. 3.) Ground to pass through a 20-mesh
sieve, it gave a very lean mass on the additen of 25
per cent. of water.

FIRE CLAYS. 145

The air shrinkage was 2 per cent.

At 2400° F. the brick was very loose and crumbly.

At 2500° F. shrinkage 11 per cent.

At 2600° F. shrinkage 18 per cent.

At 3150° F. shrinkage 22 per cent. Totally unaf-
fected.

Analysis of Bauxite, Rock Run, Cherokee Oo., No. 3.

DU Lesbinss Sh oee> Averateaas eee sieia Ree eale: wed ata 3.30
ANNs ake oereny Sewens sgdawier oa gaa eces 69.0¢
Ferric: oxid@..ess2<< cheeee seeees weeEgeeecuss 20
TMG ssiccrs akateges Skwsied tics sheeeese 4004
Wateri.cscnct~ wisiisadtco Wamsiiie te: eidmane Aree 28.10
100.66

48.(No. 4.) Three mixtures were made up as
follows:

a. 83 per cent. smaller than 20-mesh.
67 per cent. 10-20 mesh.
b. Under 30 mesh.
c. Under 20-mesn.
All three gave lean mixtures.
a. Took 23 per cent. water to work it up.
b. Took 20 per cent. water to work it up.
c. Took 24 per cent. water to work it up.
The air shrinkage was b. 2 per cent., c. 1 per cent.
At 2400° F. b showed 10 per cent. shrinkage and
the particles barely colored.
At 2500°F. b had shrunk 11 per cent. and held;
c 13 per cent. but was very loose. :
At 2600° F. b. and c. had both shrunk 13 per cent.
‘but could still be scratched by the knife.
At 3000° F. the bauxite was unaffected, and show-
ed a total shrinkage of 17 per cent.

146 DETAILED REPORT ON ALABAMA CLAYS.

Analysis of Bauxite, Rock Run, Cherokee Oo., No. 4,

SiliGaasccsce Sea KCES See ee. Wed es. 64 Sew ees 3.30
PVM MING oe sss6s Sao awe hte Ae Saha ak At, Ss Saher oR ns 66.70
Ferrie: Oxlde@insausec sieaes bts: whe Mew FSG Guepeuersee ES “10
Wate Bisvicisicasie. in yuedidepue, Sdacsunseneese “ssdoveriimiae’ saver ale 32 31.30

101.40

49. (No. 5.) Mixtures made were:

a. 85 per cent. 10-20 mesh and 65 per cent. under
20 mesh. Required 18 per cent. of water to work up.

b. under 30-mesh. Required 20 per cent. of water.

c. under 20-mesh. Required 25 per cent. of water.

The air shrinkage of all was 1 to 2 per cent.

At 2550° F. the shrinkage was 20 per cent.

The bauxite when heated to cone 30 in the Deville
furnace, preserved its form and sharp edges, and
showed the faintest trace of incipient fusion. It is
therefore highly refractory.

Analysis of Bauxite, Rock Run, Cherokee Co., No. 5.

TIC sisialec Dek <dimneisatun ce maghons Saale oe: Abate als 28
BRIMING ase Keaeead SYURRERNA GR C4 Sax 4 RRR REDE 68.14
FORCie ORIG cae whee 8 kee hea aR ORE ERE Ss trace
WiatePoieika oe cies en Paine. Sees ae ae eaten 32.60

101.02

73. (No. 6.) A whitish, claylike bauxite. This
took 46 per cent. of water to work it up and gave a
fairly plastic mass, but had very little tensile
strength.

At 2400° F. the shrinkage was 10 per cent., brick-
let still soft enough to be scratched by the nail.

‘At 2550° F. shrinkage 27 per cent.

At 2600° F. shrinkage 30 per cent., brick resisted
scratching by a knife.

At 3100° F. bauxite dense, gray in color, but form
perfectly sharp.

FIRE OLAYS. : 147

Analysis of Bauwite, Rock Run, Cherokee Oo., No. 6.

Billet veciscine sSadslsaion sake over Yeeee acaiis 9.50
Alumina........ NREL EA. Votes aRuetiee. we era 61.14
Pre ORIGGisecan vee 60545 weceeeneee neue trace
DIM ces s 9s Ms essaee bare cmats cece anaes eulumieawetes trace
MASTERGeL a aN Sk Ga ahokee SERN we Maeeaa kOe trace
WHE NGhGheadk KaGeeeeenes NEU RS ys debedeee 31.20

101.84

The foregoing tests of these bauxites show a high
refractoriness, but also a very high shrinkage which
increases apparently with the fineness of grain. It
is difficult to draw conclusions from six specimens,
however, just what the relations of silica, alumina,
water and size of grain are which influence the shrink-
age. :

All of these bauxities would, of course, have to be
first calcined if used for refractory purposes; but
they could then be mixed with a small amount of
plastic clay to serve as binder and would then make
a very refractory article. In my report I shal! dis-
cuss this point.

(No. 117)
FIRE CLAY.

NEAR VALLEY HEAD, DEKALB COUNTY.

The clay mines of the Montagues are situated about
two mile up the railroad from Valley Head, and a
few hundred feet to the west of the track. Several
grades of clay are obtained from the mines, but they
are not restricted in any case to certain layers. The
following sample tested is what is known at the mines
as the first grade, and its refractory character is not
by any means low.

The material is a white sandy clay, rather coarse

148 DETAILED REPORT ON ALABAMA CLAYS.

grained and containing occasional reddish or pinkish
stains. There is no mica to be seen in it. . It is hard
but very porous, and practically does not slake when
immersed in water for a long period.

When mixed with 35 per cent.-of water it gave a
gritty but lean mass, which had an air shrinkage of 4
per cent. In this case it had been ground to pass
through a 60-mesh sieve. When ground to pass
through a 100 mesh sieve it absorbed the same quanti-
ty of water but the plasticity was slightly increased,
while the air shrinkage remaired about the same.

At 2100° F. the clay burns white; at 2300° F. it is
white with a slight tinge of yellow, and at 2350" F. it
is the same with the total shrinkage amounting to
only 4 per cent. Incipient fusion occurs at 2400° F.
and at cone 27 in the Deville furnace the clay vitri-
fied.

The tensile strencth is very low, not over 5 or 6
pounds per square inch.

The chemical analysis yielded :

Analysis of Fire Olay, near Valley Head, DeKalb Co. (No. 117).

Billet. sa aeesep eases ateese ee Gauntlet ance eas 82.04
AWMINGs .cacds sageeiiennass aeeedisees Seeenes 12.17
MOETIC OL OG sshscarid cca aids Gisvaison” cewlaue ney eho aces, “at trace
AMCs. o.o.cce-ater Stee Ges (AM Raa adidas ee nea trace
MaPNGSIOn cca cae care cae mie adrearamne Lmao ee 827
AIBSGHES ised Surat Ghee on. a vngee waa .60
TSnitlON csi ageagee +eAWRRES OR BER RE RE SaS 4.325
99.462

Total RORCB:ésveetescesscssiccssvenss, sssersoensecncensacstcerssonserecsesessze 9 27

Specific gTAVity..........ccccccstrenrsserse sovcascerseroraeeseeeeseeeee sssces 2.38

The rational composition is:

Clay substance........ cece cece ee ce eeeeeene 31.10
QUATESY sco ties) Siete duoreussaae” “Rvesnadaa ete Gua eeeces OPTS .+. 64.80
Peldspar csiccaa « Sacinciatwie enemies ere teen cee 3.90

IRL CLAYS, . 149

~ (No. 116.)
FIRE CLAY.

NEAR VALLEY HEAD, DEKALB COUNTY.

Occurring in the same quarry is what is known as
the second grade of fireclay. This is a fine grained
yellowish gray clay containing much fine grit. It
slakes quite quicklv when thrown in water, and when
worked up with 39 per cent. of water gave quite a
plastic mass. The air shrinkage of the bricklets am-
ounted to 8 per cent. which is greater than that of the
first grade, which was also less plastic. The tensile
strength seems to have increased with the plasticity
for it amounted to 20 pounds per square inch. When
burned to 2350° F. the total shrinkage was 17 per
cent. and incipient fusion took place, while vitrifica-
tion occurred at 2700° F. and at cone 27 in the Deville
furnace the clay fused but did not run. It will be
thus seen that it is less refractery than the so called
first grade, which only vitrified at this latter temper-
ature. Both are to be classed as fireclays however.
Up to incipient fusion, the clay remains white, but
above that it begins to show a yellowish tint due to
the presence of iron oxide in the clay.

The chemical composition of the clay is:

Analysis of Fire Olay, near Valley Head, DeKalb Co. (No. 116).

Magnesia. .
Alkalies...

Total MUxes.. 0.266 cpecdw See eee nee eee 3.50
Specific gravity........0. seevevee covceeee 2.37

150 DETAILED REPORT ON ALABAMA CLAYS.

‘The rational analysis of the clay gave:

Clay substance.... ce... eee cee cee eee ees 31.20
QUATEB a cis: kcreidinie “weueusienrer eee ES Sa. Bek eae 58.00
Weld sSpaPinwiccec-c- x scaiisnaieie, 4 spveveremusres0 Seipaven BS 848 10.80
100.00

(No. 119).

FIRE CLAY,

FROM NEAR FORT PAYNE, DEKALB COUNTY.

Major F. Y. Anderson has made several openings to
the west of the Alabama Great Southern Railroad at
several points between Valley Head and Fort Payne.

The clay found in these pits is in appearance not
unlike that which is found in the mines of Montague
and Griffin to the northward. The different grades
are recognized.

The second grade, as it is called, No. 119, isa
somewhat soft, gritty, lean clay, of a yellowish color,
due to the numerous stains of iron oxide, and when
thrown into the water slakes slowly to a powder.

Forty per cent. of water gave a lean mass, and the
air shrinkage of the bricklet made from this was 8 per
cent. Incipient fusion occurs at 2300° F., the total
shrinkage at this point being 14 per cent, and the
bricklet is yellowish white. When heated to cone 27
in the Deville furnace the clay showed vitrification.
While it is fairly refractory in its nature, at the same
time, owing to the yellowish tint developed in burn-
ing, it would not, in its natural condition, do for the
manufacture of white ware. It is possible, however,
that washing might eliminate some of the undesirable
impurities.

The chemical composition ‘s as follows:

FIRE CLAYS. 161

Analysis of Fire Olay, near. Fort Payne, DeKalb Co. (No. 119).

Bilehsvcdgavs song eh anes Lieceeeu: 2S0see panes 66.25
ATID) sess, aacacsneuat” “mucincinaeiseh hie", eae by » Reesnaea 22.90
BeOS PRG ose Wecdek bebedewe Vaud e KISRER 1.60
EAMG ii: tcocacacs wert Geile Lptelsseinenin case, aeelewe trace
Magnesia...... .... {te Ses ee eS SeMtwR le aimee trace
Alkalles .sisgiee aetege aaanaine Pavwne <44acunrs 75
ISMITIONS csnciwiis a eryncis? Gasrentaaue a cues Qanea a4 9.05

100.55
DOtal. HUXCs as.cud sau. Ges Paw aaiases asoeeaeee Se 2.35
SPCCiAG TAVIEY i ecccccacaue ved aedeieed aredae’ss Mv aswace 2.28

The rational analysis yielded :

Clay BUDStANCE sce occ areas naan Siwaleaieris kieve eee 40.70
QUIETER) se eseeng eg cae anicke Guedes, ocass a, (ieiaidagiie nde des a bias s 47.90
POlGSD OTs ie Sime acancane Keay dies per Bee eee 11.20
99.80
(Ne. 112).
FIRE CLAY,

FROM BIBBVILLE, BIBB COUNTY.

This is one of the clays used by the fire brick works
at Bessemer, near Birmingham. For use it is mixed
with several other clays.

The material itself, however, is a very sandy clay,
with much coarse grit and appreciable quantity of
mica. It is also abundantly stained with limonite in
places. When thrown into water it slakes fairly fast
and falls to powder. It is quite a plastic clay, but in
working it up into a plastic mass it took only 22.6 per
cent. of water.

The air shrinkage amounts to 64 per cent. At
about 2200° F. the clay burns creamy white, and
shows a total linear shrinkage of 9 per cent. While
at about 2300° F. incipient fusion is reached, with the
shrinkage the same, and the color buff. Vitrification

152 DETAILED REPORT ON ALABAMA OLAYS.

was not attained until the clay was heated to cone 27
in the Devilie furnace, and ever at this temperature
the clay cone remained still perfectly sharp.

The tensile strength is moderate, ranging from 15
to 110 pounds per square inch, with an average of 102
pounds per square inch.

The analysis of this fire clay is:

Analysis of Fire Clay, Bibbville, Bibb Co. (No. 112).

SUTUG Ae giao gig face atone ads (Ahead ater Gee PRBIERE sensing * 74.25
AUMINGs cisce gaan Gea wada eae GRMEE ES CF 17.25
Ferric oxide..... cece eee cee eee cent ne teers 1.19
TAME. Cc ccekw AMER ENGS GEER ES aR STR SPREE eas ERO 40
MagMeslieweacec seesdides GERRRHSPEN ae FR REe eee tr.
AUBALICS® kcysiclacclen the Gide bier gridoalahe the GARDE oa 52
Tgnitloticcss. cseneacn stewereey cis eeewr ede ree es 6.30

99.39
Total Muwes: say cveusagae aeeeae Seev eases saneus 2.11
Spetifie WAVY: ccsnagd execs So anwadew 44 eeeeS 2.44

(No, 111).

FIRE CLAY,
ELGIN PROPERTY, NEAR WOODSTOCK, BIBB COUNTY.

A sandy, micaceous clay, of yellowish color, which
breaks up slowly, but completely, when immersed in
water. This needed 23 per cent. of water to work it
up, and gave a moderately plastic mass. The air
shrinkage amounted to 7 per cent. In burning the
bricklets incipient fusion occurred at 2150° F., with a
total shrinkage of 14 per cent., and the color of the
clay light buff. At about 2300° F. the shrinkage was
16 per cent., and the color yelow. Vitrification took
place at 2350° F., and at this point the shrinkage had
incresaed to 18 per cent., while the color had
changed to grayish. Fusion tock place at 2900° F.

FIRE CLAYS. 153

The tensile strength is moderate, and varied from 100
to 110 pounds per square inch.
The ultimate compcsition is:

Analysis of Fire Clay, Woodstock, Bibb Co. (No. 111).

Sillege oss ewewu se qaaee. evans: o homatidal eelediely suey 65.82
Alumina: sancesenues setewatds saaunnds xeea 04a 24.58
Werric: Oxide: sites, seussdecs aadidvs ea coeahhan 448% 1.25
TMC grs ss Recs eahigaunnad < ayauad eats uk ees wes - BNE
MASNOB18 ccs. Suen HAR ka: DoRMERGAE GE IKes tr.
AlKGHES) <2.c.54.quaiinars. ariicclseiies eatin uae ia Grseweees .60
TGOION irate. seach eee: aes along ke niad abe wena 8.165
100.415
Total MUxesvisxaon- whee bade Gdoeee! aoas.ckl a oewen 1.85
Specific gravity .........0 cece cece eee cece eeeees 2.40

The rational analysis gave:

Clay substance

Diehl Gi) otttrensastice Jove favor ahaiara eels cay lietacbeers 62.90

Feldspar

rane \ saa e, Ui ditesiate nce Gaekis lees yi Raids 37.00
99.90

(No. B).

FIRE CLAY,
AUXFORD'S, NEAR HULL’S STATION, TUSCALOOSA CO.

This is a sandy micaceous gray clay, with a slightly
reddish tinge, which crumbles to pieces very quickly
when immersed in water. When worked up it gives
quite a plastic mass, and requires 33 per cent. of
water to accomplish it.

The air shrinkage is from 9 to 10 per cent., and at
‘2000° F. the total shrinkage was only 12 per cent. At
this latter temperature the bricklet was hard, grayish
red in color, but still somewhat absorbent, while at
about 2200° F. vitrification occurred, with a_ total
shrinkage of 14 per cent. The viscosity occurred at

154 DETAILED REPORT ON ALABAMA CLAYS.

2500° F. The average tensile strength of the bricklet
was 155 pounds per square inch, with a minimum of
140 pounds and a maximum of 168 pounds, which is
very good.

The composition of the clay is as follows:

Analysis of Fire Clay, Hull’s Station, Tuscaloosa Oo. (No. B.)

SICA cc ci ease aa ee ess He wewe ae Ea Hee eg gece 61.25
AlUMiNA... cece cee ee te eee teen ee ween 25.60
Ferric oxide. ....... se ccee cece eee ceeeee tees 2.10
EAMG. ais seetsiete, ccs etiam See Sree a mee eee aS 25
MGSNCSIR sss Seca eee Sica SS hae ereree 82
AIKACS. 6 cece eee cece eee cee teen eeeeee 1.35
Ignition...... ...ee- See SRteses Stivwnlews Fase 8.10

99.47
Total fluxes .......005 seccevecvececee seeeenee 4.52

(No. 118).

FIRE CLAY,
J. C. BEAN, TUSCALOOSA COUNTY.

It is a fine grained clay, with very little grit, and of
homogeneous structure. When immersed in water it
slakes with extreme slowness. The addition of 36
per cent. of water to the clay gives a very plastic mass
and the bricklets made from this had an air shrinkage
of 12 per cent. ,

When burned to 2200° F. the total shrinkage
amounted to 18 per cent., the bricklet was grayish red
in color, and very dense, incipient fusion having
occurred. When heated to cone 27 in the Deville
furnace it only vitrified.

The burning dense of this clay at such a ten Dera-
ture, and the great difference in temperature between
the points of incipicnt sintering and vitrification are

FIRE CLAYS.

155

worthy of notice, and show it to possess character

closely resembling those of many glass pot clays.

The composition of this clay is as follows:

Analysis of Fire Olay, Tuscaloosa Co. (No. 118).

Silicasceg) ihre eed -suseevewe (4a Bees 58.13
ALUMINA siicsccie iss seeped SResEReIVere Saeaaee 24.68
Perri¢: 0xide.owses isdanneaind S350 Kas amma ae 3.85
TAMES see overs ve ated Gee ew, ecw iy ice Mearselee 15
DISGRGOIE. oy chicas Geen awe: WABEES Pork Bedeaners .82
AlKANOSls2oiciai assy angen wercgeaie oaaed ecaliers 1.78
WBA ON ss. oe eae es, domweddily es! 2 aes Wun as 11.78

100.51
WOtal, MUS csiciein, enw eine wedatawa eons’ 5.92

The rational composition is:

Clay BUbStANCE siecida sige: Giaieseiesagies seslbuelewwusles 60.85
QUATEA 5 4 crsdorasaas ccnsncussasetesacgs censvanttarallacer cohssensuieadeulseve 23.35
WGLOSD AP. tiydin sates ea auclaieaee web uhangreer Getbaiueveee 15.80

100.00

Glass pot clays vary in chemical composition, and
it is really the physical behavior of the material
which it is of importance to know. At the same time
the analyses of several other glass pot clays are given

below for comparison.

Analysis of Glass Pot Clays

Ignition...... ete ee name eceee of sere eenees we

156 DETAILED REPORT ON ALABAMA CLAYS.

No. 2.
SUitdauuw ie ees Rese Oe S56 Slee eu Aenea aioe 55.61
AIUMINS. cicada e5044 Fe Beet eee ee Bea Re ee 27.36
Ferric oxide ......... cece cece cone en ee neenee 2.73
TAMCaaicwen cavetac kbeeeea Wg SARS RESRS BHRLETES 87
MaTGSIA scien g Yess sisi loerhaation aie Baas time hee 07
AlkalieS.. 0... cece cece ce cece cee eens cane eeee 71
Titanic oxide ........ ..+---- SG Kamla s ose eie 1.36
Sulphuric acid* 2.0... 2.05 cee ence e eee cee eereee 51
MOIStureiciice dca. vaca [o DEDEDE: LAT ASGRS A OHM 2.26
Ignition........ . ee oe ee ee ee ee 11.13
SSulphurscwasess cai xaeeew SeaGaum REp doses wae 25

No 1 is from Layton Station, Pa. (18)7 Report Pennsylvania S'ata College, p. 90,
T. C. Hopkins).

No. 2, St. Louis, Mo., Washed pot clay (Missowri Geological Survey Report, Vo'.
XI, p. 5€8.)

(No. 1).
FIRE CLAY,

PEARCE'S MILLS, MARION COUNTY.

This clay forms a bed from four to six feet thick in
the ravine to the east of the mill. It is a hard rock-
like material, and when mined has more the appear-
ance of a white argillaceous sandstone than a clay.
It is very hard, and when thrown into water practi-
cally does not slake at all, but it is very porous.
Wher ground to 30 mesh and mixed with water it is
very lean, but grinding it to 80 mesh increases the
plasticity. In this latter condition it required 37 per
cent. of water to work it up. The air shrinkage was
4 per cent., whereas when burned to 2100° F. it was 5
per cent., and at 2200° F. the total shrinkage was 74
per cent., the color of the bricklet being still white
like the original clay, but the porosity great. At
about 2300° F. the bricklet developed a slightly gray-
ish tint, and at 2400° the color was the same, but the

FIRE CLAYS. 157

total shrink:.ge 10 per cent Incipient fusion did not
occur until heated to cone 27 in the Deville furnace.
This is a very refractory clay, and one that has a
comparatively low shrinkage, due to the large
amount of silica in its composition. :

Vitrification occurs at cone 30 and viscosity at
cone 33 in the Deville furnace.

The composition of this clay is:

Analysis of Fire Clay, Pearce’s Mill, Marion Oo. (No. 1).

LICE iiss Fz sane secertila Gayeadinnpie doh Se anjewara ae Mesa cera ma eagueee 52.95
TUM NG es seces! Sa hl Rae Seana aoe Dla aes 35.10
Ferric oxide sasccc stacdwwed woes ges esac eeewn -80
ALM edhe sensaissattey Yas ahayoardase, Leaendls Cavebisride” lceiid amotio eta ae tr.
Magnesia). js cisicirsc wuiighlas yas oswalaiaewd Saeanes tr.
AIBANGS sua samen eew GENES 42 4ARERE ONER KG Bees -93
Ignition...... ... eee eee eee cece eee veeeeaae 11.40
101.18
Total MUxeB ccc exceeee weve ie aseeus wae es avis 1.73
No, 2).
FIRE CLAY,

PEARCE'S MILLS, MARION COUNTY.

This sample is from a second opening which closely
adjoins Pearce’s Store, and like the other occurrence
in this vicinity, it is very gritty, being even more so
than the first, and while the material is very porous,
at the same time it slakes very slowly, falling finally
to a powdery mass. The fracture of the dry material
is hard and angular, the air shrinkage is very low,
amounting to only 2 per cent., in the case of sample
which had passed through a 30-mesh sieve.

At 2350° F. the shrinkage is only 6 per cent., and
the bricklet was creamy white in color, but still very
absorbent. In the Deville furnace incipient fusion

158 DETAILED REPORT ON ALABAMA CLAYS.

occurs at cone 27, vitrification at cone 32 and viscos-
ity at cone 34,

The tensile strength is very low, ranging from 5
to 10 pounds.

The very refractory character of this clay is evi-
dent, but its leanness would no doubt necessitate its
being mixed with a more plastic clay before it could
be used.

(No, 57 8.)

FIRE CLAY,
J. W. WILLIAMS, PEGRAM, COLBERT COUNTY.

A black gritty clay, which slakes easily, considera-
ble organic matter present, but no pyrite or mica no-
ticeable.

It required 28.6 per cent. of water to make a
workable mass, which, to the feel, was lean and
gritty. Bricklets made of this shrank 10 per cent. in
drying and 3 per cent. in burning, giving a total
shrinkage of 13 per cent.

The average tensile strength of the air-dried
briquettes was 46 pounds per square inch.

Incipient fusion occurs at 2150° F., vitrification at
2350° F., and viscosity at 2500° F.

The clay burns to a white body, slightly tinged
with yellow.

The following is its chemical composition:

Analysis of Fire Clay, J. W. Williams, Pegram, Colbert Co. (No. 57, 8.)

MOIStUTE J scimitar sided Ea Getienr GRE ES 1.70

Bitiee. (OA ios eeeees 8858 veneeds 80.55, free sand 70.10
AVUTOINGi series oH wares anil vale 10.50 .

Merrie Ox1de@02 ig 6 cies eb, Wales 1.53

LiGt@ cece sebeseae Mein say oeaeee 34

Magnesia visi. weaken o50 casieies traces

Water and organic matter ..... 5.85

100.47

Total flures..i.2. 0 sceeces 4% Beers 1.87

FIRE CLAYS. 159

(No. ©. 8.)

FLINT CLAY,
CHOCTAW COUNTY.

A hard, fine grained, siliceous clay, resembling flint
clay-in appearance, but containing more silica than
such material usually contains. It presents a
smooth surface, with conchoidal fracture, and in wa-
ter practically does not slake at all.

When ground to pass through a 30-mesh sieve it re-
quired 15 per cent. of water to make a workable paste
and was very lean and granular. The tensile
strength was, on the average, 5 pounds per square
inch.

The shrinkage in drying was 2 per cent., and at
2300° F. 6 per cent. Incipient fusion occurs at 2300°
F., vitrification at 2500° F. and viscosity at 2650° F.

On acceount of its refractory qualities and low
shrinkage, this flinty clay is admirably adapted for
admixture with plastic fire clays to serve as grog and
prevent undesirable shrinkage. The following two
analyses, No. 1, by W. B. Philips, and No. 2, by H.
Ries, give the composition of this material :

Analysis of Fire Clay, Choctaw Co. (No. C. 8.)

(2)

Silica (total) 85.70
Alumina..... sara = 6.15
Ferric oxide...... sseeeeeee . : 1.80
Lime........ é tr.
Wateliacac faceces: Adie Bates sate : 7.00
100.08 100.65
Total fluxe@s. <scieawe cermin seneineis 2.06 1.80
Specify gravity... ..... «.. fap dete tess * 1.70

*This is a Radiolarion clay, abundant in. the Buhrstone division of the
Tertiary formation in many localities in Choctaw, Washington, Clarke,
Monroe and Conecuh counties. H. A. 8.

160 DETAILED REPORT ON ALABAMA CLAYS.
POTTERY OR STONEWARE CLAYS.

Many clays which are too impure to be used as fire
clays are often admirably adapted for pottery pur-
poses. In fact stone ware clays are often somewhat
intermediate in their nature between fire clays and
pipe clays, that is to say they are too impure for the
one purpose and too good for the other.

In the manufacture of stoneware, it is highly es-
sential that the clay should burn to a dense imper-
vious body without requiring too high a temperature
to accomplish this, and furthermore if the ware is to
be unglazed or is to be coated with a transparent
glaze it is important that the clay should burn to a
good uniform color. In order to obtain the desired
result it is not uncommonly the rule to use a mixture
of two or more clays for this purpose.

A stoneware clay should be smooth, and free from
coarse grit, otherwise it may be necessary to wash the
material, and thus increase the cost of manufacture.
The clay, in addition, should be highly plastic in or-
der to permit its being easily moulded without crack-
ing, and the tensile strength should be not less than
150 pounds per square inch. As the ware is to be
burned to a vitrified body, it is also desirable that
there should be a difference of 159° to 250° F. between
the point of vitrification and viscosity. (Earthen-
ware clays are not vitrified.) Excessive plasitcity is un-
desirable as it necessitates very slow drying and burn-
ing of the ware and consequently increases the cost
of manufacture; while on the other hand low shrink-
age diminishes the loss from cracking or warping.

Iron is a desirable ingredient not only as it tends to
give the body a good red color, but in addition serves
asafinx. Lime if present as a silicate may form a

POTTERY OR STONEWARBD OLAYS. 161

desirable flux, but carbonate of lime especially if in
greater quantities than two or three per cent. is
objectionable, and sulphate of lime is likewise not
desired as owing to its disassoc‘ation at high temper-
atures blisters may be formed.

A clay vitrifying at a low temperature is more
desirable as it requires fuel to burn it.

The pottery clays reported on are all from the
Tuscaloosa formation of the Lower Cretaceous except
No. 204 from Blount county, and No. 192 from near
Rock Run, both of which come from the Paleozoie
limestone formations.

(No. 204.)
STONEWARE CLAY

FROM F. 8S. WHITE, BLOUNT CO.

A yery fine grained sedimentary clay of grayish white
color with occasional spots of yellow.

It slakes easily when thrown into water and works up
to a very plastic mass with 28 per cent. of water. The
bricklets made from this had an air shrinkage of 5 per
cent,

Then burned at 2200° F. it is nearly dense, cream gray
in color and showed a total shrinkage of 17 per cent.

At 2350° F. was vitrified and showed very light gray
color and a total shrinkage of 20 per cent.

It fused at the time at cone 27 in the Deville furnace.

The tensile strength of the air dried briquettes was low,
ranging from 45 pounds per square inch to 55 pounds
per square inch.

The analysis of the clay yielded:

162 DETAILED REPORT ON ALABAMA CLAYS.

Analysis of Stoneware Clay, Blount Co. (No. 204).

Sila cae inde. siseanend S228SERR Shee ew Seeds 61.50
MUMING.cccck cnowas 225608Re aGEKMeRE. EASES 26.20
Ferric Oxide 1.2... cece tees cece nee teens 2.10
IMS say. advereternnaess eed ala taeids word enero vondlenty eases 0.50
MASUCSlAs sa gs 4buee ee Feseeee Seaweeds He moe 0.43
AIKSNGSS sec cgeeee BERET E ees Gants s smears 0.70
TEHIUIOD 6... ceted SEHK TS BESHHE Ceo oe ward 7.29
98.72

3.73

Total. HUXESsscm Aeeew ey see Kage e Hew eco gra rscenens

While this clay is not highly refractory, at the same
time it has about the right refractoriness to be used in the
manufacture of stoneware, and owing to the dense body
to which it burns, is exeellently adapted probably to mix
with more opened grained clays, which require a good
binding material.

(No. 192.)

POTTERY CLAY
FROM C. C, DAVENPORT, ROCK RUN, CHEROKEE CO.

A green clay, of extreme fineness of grain, great density
and breaking with a conschiodal fracture. In water it
slackens rapidly to a flocculent mass.

It took 30 per cent of water to work it up and it yielded
a lean aud somewhat granular mass, which had an air
skrinkage of 9 per cent.

The bricklets made from this clay burn to a greenish
brown color, and vitrify easily at about 2000° F.

Atabout 1800° F. incipient fusion occurs, with total
shrinkage of 18 per cent.,and color brown. The clay
fuses to a glassy mass at about 2150° F.

The average tensile strength of the air dried briquettes
was 62 pounds per square inch, with a maximum of 70
pounds.

The analysis of the clay shows as follows:

POTTERY OR STONEWARE CLAYS. 163

Analysis of Pottery Clay, Rock Run, Cherokee Oo. (No. 192).

PU ks OF eENEe See eW. VaKeReNS. waaennbe 57.00%
ALUMINA 2285 eeeeree Kagem “AdSe ese Lesdsang 17.80
Werrle Ox1d@..siscwa Guwivesis daoweods 245 inde 5.60
Dimeniede i ateonaydxe ceatioumes. orietense -tead44 2.10
MAGNESIA eae -Leaee ttc: “ike Wis cue diac aye “enersvepepaner a tnecd 1.20
AIK ONES sack ttnaarey cee teedidlies GG Ses SSdeaar! Gea Rees 6.00
SPO Heme ead eeee BIER WER BONG RE RES GaSe 9.45
99.15
MOA ci a,nie uals witches wean, 9 dessa Wawteaunce ais 14.90

The high percentage of fluxes accounts for its easy
fusibility, and the best use for this material would per-
haps be as a natural glaze. It is exceedingly fine grained.
When a slip is made of it and No. 205 (clay from near
Kymulga) dipped into it, at cone 3-4 it yielded a trans-
parent glaze.

CHALK BLUFF, ELMORE COUNTY.

At this locality there is a high bluff of clay and sand.
The section involves approximately :

Section at Chalk Bluff, Elmore Co.

DANG wis Rates” wader Gan’ eee Sere CHAOS 6 feet
MeOlOw: “Gay. Gee do e-seseisie atevacsnind) eueneve led de arecese stave 4 feet
Dark--SAndy® :Cla Vivi oes. oes Gun” Vedeieretaweaards es 12 feet
Plasti¢. clayiedcsccs neaadek dadtembe aed ee wd 10 feet

Both the dark sandy, and lower plastic clay were tested
and yielded very promising results. The lower bed yields
a stoneware clay, and the upper a brick clay. (See Nos.
101 and 122.)

(No. 101.)
STONEWARE CLAY.
CHALK BLUFF, ELMORE CO.

This is a reddish gray fine grained clay, containing
much fine mica and also an abundance af crganic matter.
In water it slakes very slowly. The addition of 38 per:

164 DETAILED REPORT ON ALABAMA CLAYS.

cent. of water to the air dried clay gives a fairly elastic
mass, and bricklets made from this have an air shrinkage
of 6 per cent. At 2100° F. the total shrinkage is 11 per
cent., and the color of the burned clay is s»mewhat red-
dish. Incipient fusion occurs at this temperature, while
vitrification takes place at 2200° F. with a total shrink-
age of 13 per cent., the color of the clay when burned to
this point being a dull red. Viscosity took yplace at
2600°, so that the clay is not to be classed as a fire clay,
it would probably work however for vitrified ware. The
tensile strength is exceedingly high, and runs from 300
to 384 pounds per square inch, and while there is con-
slderable variation, at the same time even the lower figure
is very great.
The chemical composition is:

Analysis of Stoneware Clay, Chalk Bluff, Elmore Co. (No. 101).

BIWCA! ec ie e E8eaa es SER ee TAA eee Se hea at 60.38
AUTON Bs aces git code beakan bag eecd atereien ae CRM Sara eae 20.21
MOEPIC ORIG® j hherctdei Anis aiiedavan ele, “Gamma, eomue 6.16
EAMG sia: Cheek 5 Sea oS A ARAL AER UN Oo .09
Magnesias.: aciscwecaees aeweieewase werew enw we -720
Alkalieg: «see iste esse see tone areca aed, oa tees 1.80
VONIUODi ie ask a ee pig Pa RRAES~ ale panded 10.21
99.570
TOCA BURGESS 2 s.h2.60 sence dear ded cb ersucteledac oud 8 deausnienens nde 8.77

(Nos. 88 and 89.)

POTTERY CLAY.
McLEAN’S, EDGEWOOD, ELMORE CO.

Considerable clay is dug for pottery on the land of Mr.
McLean, 4 miles from Prattville, along the line of the C.
M.R.R. This clay occurs in large pockets surrounded
by sand, it is chiefly of two kinds, i. e., a smooth plastic
clay and a sandy one.

The former (No. 88) is very tough, and quite plastic.

POTTERY OR STONEWARE CLAYS. 165

In water it slakes in augular fragments, and when worked,
requires 32 per cent. of water to develop its plasticity.
The clay is rather fine grained, but with a conchidal
fracture, and shows iron stains on its joint surfaces.

The tensile strength does not appear in this case to
stand in direct relation to the plasticity, for the maximum
is only 56 pounds per square inch, and the average 49
pounds.

The clay burns to a buff color, and a dense body, and
is quite refractory.

The total shrinkage at 2350° F. is 18 per cent. At
2700 it is 18.05 per cent.

In the Deville furnace, at cone 30, the clay vitrified
and showed no evidence of becoming viscous.

The second or sandy clay (No. 89) slakes very quickly.
It gives a moderately plastic, but though not so tough a
mass as the preceding. The tensile strength is however
higher, being 74 pounds on the average, and 92 at the
maximum.

The air shrinkage is 8.75 per cent; at 2200° F. the
total shrinkage was 11 per cent.; at 2350° the total shrink-
age was 12 per cent.

The clay fuses at cone 30 in the Deville furnace.

Associated with these stoneware clays is a bed of ochre
which fuses easily to a brownish glass. Its composition
is:

Analysis of Ochre, Edgewood, Elmore Co.

SillG@ ciccrcacs ced 8S BeOS ieee a a aeeretiace 51.14
Alumina .........05 cece eee cere e eee teens 30.13
Ferfic Oxide ......6. cee ece ee cere eens teteeee 8.35
b 0 0. an rr oe tr.
Magnesia.... 2. cece ee cee eee eee rere e eens tr.
Alkalies .......6. cenccccees coeerctees rereee tr.
Tents see sacar daee He ORK 2 R E EEE 10.15

166 DETAILED REPORT ON ALABAMA CLAYS.

(No. P. S.)

POTTERY CLAY (BLUISH.)
FROM McLEAN POTIERY, ELMORE CO.

A compact bluish clay which slakes rather quickly in
water. It shows little grit tothe taste. It required 20
per cent. of water to make a workable mass, which to the
feel was smooth and plastic. This mud shrunk 6 per cent.
in drying and an additional 6 per cent. in burning, giv-
ing a total shrinkage of 12 per cent. The average tensile
strength of the air dried briquettes was 55 pounds per
square inch with a maximum of 66 pounds. Incipient
fusion occurred at 1950° F., vitrification at 2150° F. and
viscosity at 2400° F.

The clay burns to a dense, smooth, bluish white body,
and should make’a good stoneware clay. In burning it
had to be heated slowly.

The analysis of it is as follows:

Analysis of Pottery Olay, McLean’s, Bdgewood, Elmore Co. (No. P. 8.)

SiliGa’. (COCA) 58 tees ce-a ¢ kyiad honed e. BoRaaeod 62.60
PATTI Diissein Taco ik attncenany BA RV elelee Pe-aeaweek) aedeagal 26.98
WALD: Scisisianine sg, Mekmintdesaue el niin afore me es 8.60
GEDIC: ORIGO” cin Rick faeces Shain y aipoon Gg SBA ee awe 72
TMG ies. axet anew Macaca aaa hes emeeeen eeenon 40
MABNOBIA. since cciid! Sehnert SB enced Sbeed vec kay -86
Alkalies ss caicaice Selemm enn e. Sagaeeee woe aes -65
MOIStUTG sivas ae as Saenger Gon amamone 6 eee o gebabedneg 70

101.01
Pree SiC sho. aris a hae Rate eee. eee ee, eee 30.10
POLA (AUROS: eee -cdeeetlew: Ae RLERR” Glee ee aod Doe 2.13
Sepeiby eravity: pine iwwe yey ao audacious Geena 2.37

STONEWARE CLAY
FROM NEAR COOSADA, ELMORE CO.

This is a moderately fine grained but somewhat gritty
clay, which however is quite plastic, requiring 26.25 per
cent. of water to develop its plasticity.

POTTERY OR STONEWARE CLAYS. 167

The tensile strength was on the average 154 pounds,
with a maximum of 170 pounds.

The air shrinkage amounted to 8.1 per cent.; at about
2200° F. the total shrinkage was 14 per cent., the clay at
this temperature having burned nearly dense, and the
brick being a brown gray color; at about 2300° F. the
total shrinkage was 15 per cent., the brick was very hard,
homogeneous, dense, and still of a brownish gray color
though somewhat darker; at 2500° F. the brick was thor-
oughly vitrified, and showed a slight swelling, the shrink-
age at this temperature being only 13.5 per cent. and the
color remained unchanged except that it was slightly
darker in shade. A test made of this clay in the Deville
furnace showed that at cone 26 it had become viscous.

The composition of the clay is as follows :

Analysis of Stoneware Clay, Coosada, Elmore Co.

Sili@deizsne secseaaeed “abeneee eee csiewadelets 66.61
AIVMING: 44:4 g52ge0% Eh Nehees See eX saeaesy 21.04
Ferric \Oxid@s..cc05. scan estas wear eseeie «ence 2.88
TAU GS sAcviynieti say tece SaGpeeausaoe” et adeveoar * stasdveeis unre ¢ heels 40
MECNESIas 6 ii kad: Gektakae Rida aaameus’ 4 eaen 58
ATKAWCS sccccnnwss Goa wa: Ga anew Ga ee Ae. a Rhee -70
Wiaterecciaie sideineck a eawom aaeacehsy WeiGice ga a7 eRe 7.00

99.21
Total fluxes 5 .sccand PG cian hw dete sericea Cease epee oreo 4.46

(No. 18.)

POTTERY CLAY.
H. H. CRIBBS, TUSCALOOSA,

This is a whitish, fine grained clay-with small amounts
of grit, which slakes easily to small irregular grains and
scales; it required 25 per cent. of water to mix it and
gave a moderately plastic mass whoseair shrinkage was 6
per cent. and fire shrinkage 4 per cent., giving a total
shrinkage of 10 per cent.; briquettes made of this paste

168 DETAILED REPORT ON ALABAMA CLAYS.

had, when air dried, a tensile strength of 68 pounds per
square inch and a maximum tensile strength of 78 pounds
per square inch.

Incipient fusion occurs at 2000° F., vitrification at
2200° F. and viscosity at 2400° F. ©

The clay burns to a dense yellowish body; the com-
position of it is as follows:

Analysis of Pottery Clay, H. H. Cribbs, Tuscaloosa (No. 1, 8.)

Total silica........... 2. S Sinewen Waa) eh Sate wtaes 65.35
ALUMINA nie ected Saas ds: wee Ree: 2 odes cee 21.30
Water inci Geagianes <SAsteees os sees es-04 State 7.35
Ferrie: OXId6 65. 265 Sd aed SSSRAM. BESTT ROS 2.72
TAM iiysyertic ea. 8 Koa vaverpeisusy Gltequanerauasesaeos eee ere sey Saer ee eeline: 60
MagmeSi! sic iaiess eesiaieare ee ae ose ee Ge ew ek Site we 86
Alkkallesin gis wists Ge este la Bekele CM aR Res tr.
MOMGUIGs aac Kee ekee ages aes wulewunt 1.44
99.62
Mires: silica. (SAD) se siesceis, ese ieioceee Grew eobiee . nveneceeese 39.25
MUA) GUE ae kane SoG KEKGNSET Bea Gann Kh SX Rew 6 4.18
Spechfic Pravity ssncasaswe cad sevadeweae eeaa prqad vs 2.34

Another analysis of this white clay from the Cribbs bed
was made by Dr. Wm. B. Phillips and is as follows.

Analysis of White Plastic Olay, Cribbs Place, Tuscaloosa, Ala.

WeUTie DEINE Anite ee ade Gane ean cies s dekas eaux
Loss at red heat

Total fluxes

If coarse grained this clay would probably work for a
low grade of fire brick, as its fusibility would probably be”
less. It would probably work for potters clay, although
it would no doubt be desirable to add a clay possessing
greater plasticity and tensile strength to it.

The comparative purposes there are given herewith the

POTTERY OR STONEWARE OLAYS.

169

tests of two Missouri clays quoted in Vol. XI of Missouri
Geological Survey. The one has a much higher tensile

strength however:

Analyses of Missouri Clays.

SUM Cai sieciis Gaggia e Laek gS eR Sasa

Alumina. Benen cere eee ne eee e eens
WALTERS ie -cys -a'aiaiaieaaien Gtisen isa Sets viele eaves

Magnesia ........... OR catia ata te de te
Alkalies... ...... wide bs Gxtiunicuse: Ghtienasiste

"POCAL DMCS? 5.3.6-4.04-54.48 Gignneuieace’ Amos

Incip. fusion ...... bite PRM AO RAR
WACVIRCATION:. suis spseend: Ver parwinete ~ aseciered
VISCOSLEY: secede seeaeee aw agense

Average tensile str., lbs. per sq. in......
Maximum tensile strength...... ......

66.26
20.32
7.80
2.30

63
48
2.04

5.45
2000°F
2200°F
2400°F

122
135

No. 1 is from Waltman’s, Barton Co., used for stoneware.

No. 2 is from Lanigan shaft, Moberly, Randolph Co.

In composition it also resembles somewhat two clays

from Ohio.*

Analysis of Ohio Clays.

Ferric: Oxildew: gicmenae os aicen gonad
EAMG cia weskes Rasee GaGa AAS

Magnesia isis «swicae aeuicinwa aa ke
ALKA CS at wou nanght amides eae
Moisture: sswsiss Sevedyecee vegasts

TOtal; MURES? sadicisine cere; ode aye ese ave

No. 1. Cooking ware clay, Laresville, Muskingum Co.

No. 2. Stoneware clay, Akron, Summit Co.

In all of these analyses it will be noticed that the per-
centage of alkalies is higher, but the total fluxes are

nearly the same, except in the last one.

*O. Geol. Surv. VII, 1893.

170 DETAILED REPORT ON ALABAMA CLAYS.

In the case of the Ohio samples no physical tests have
been made.

(No. 115.)

STONEWARE CLAY.
J. ©. BEAN, TUSCALOOSA CO,

This is from the property of J. C. Bean, near Tusca-
looso, in 8. 31, T, 20, R. 11. The bed of clay is 6 feet
thick and overlain by 4 feet of white sand.

It is a rather fine grained dense clay, which slakes very
slowly. On mixing with 36 per cent. of water, it gave a
very plastic mass, whose air shrinkage was 11 per cent.,
at 2200° F. the clay burned a pinkish brown andshowed
a total shrinkage of 16 per cent., while at 2250° F. it
burned a grayish brown with a total shrinkage of 18 per
cent. Incipient fusion occurs at 2100° F., vitrification at °
2300° F. and viscosity at cone 27 in the Deville furnace.
Owing to the extreme plastice nature of the clay it was
very hard to make briquettes which did not show evidence
of flaws so that the tensile strength ranged from only 90
to 100 pounds per square inch, which is probably low.
Specific gravity 2.40. .

(No. 100.)

POTTERY CLAY.
J. C. BEAN, TUCALOOSA CO.

This is a rather fine grained clay, and at the same time
a dense one. It contains an appreciable quantity of or-
ganic matter which not only increases the plasticity but
also necessitates slow drying and burning of the material.
The addition of 31.5 per cent. of water to the clay con-
verts it into a very plastic mass, whose shrinkage in air
drying amounted to 9 per cent. In burning incipient
fusion occurs at 2100° F., at which point the total shrink-

POTTERY OR STONEWARE CLAYS. 171

age was 14 per cent. and the bricklet buff in color. At
2200° F. the shrinkage was 16 per cent and the bricklet
grayish buff, while vitrification occurred at 2200° F. ac-
companied by a total shrinkage of 17 per cent. Viscosity
took place at 2500° F. The tensile strength was only
moderate, being 84 to 85 pounds.
The chemical composition is :
Analysis of Pottery Clay, J. O. Bean, Tuscaloosa Co. (No. 100).

SUNG Seine deve avues Las: Aadanited sie neces 60.03
PHONG so Scale eke RES EERES POSE ROSS MARSA 24.66
POPe OF10G . cicaeserteee 14s hee 8eeoaa OER RR 3.69
LAPTG i ends. Suioes care Wie averaran. -slavrevensnwyaarabinngy cig tate seals adaapatig 13
Magnesiaucc. tsar: 2vainaaah Sorkin “Gaia: BEd eS .380
AVALOS: s.aiciornhed —Skais beeen aed e age aa aon ae tr.
Wgnithon as secag walnsegue Bo eote 45 SoMa ORRG NES 11.342
100.232
OH DUSeh ects bs Gi eeen 24nteheke Gade eens 4.20
(No. 32 8.)

STONEWARE CLAY.
ROBERTS’ MILL, COAL FIRE CREEK, PICKENS CO,

A gray, tough, rather fine grained clay, which in water
slakes somewhat slowly to a mixture of grain
one-sixteenth to one-thirty-second of an inch
in size. Taste gritty. Patches of fine sand
and ore scattered through the clay, and associated with
them are a few small flakes of white mica.

The clay when ground to 30 mesh and mixed with 21.8
per cent. water gave a workable mass of quite plastic
character, which shrunk 4 per cent in drying and 8 per
cent in burning, making a total shrinkage of 12 per cent.

Air dried briquettes of the clay had an average tensile
strength of 117 pounds per square inch and a maximum
strength of 142 pounds.

Incipient fusion occurred at 2000° F\; vitrification at
2200° F. and viscosity at 2400° F.

172 DETAILED REPORT ON ALABAMA OLAYS.

The clay burned to a stiff buff body, which deepens on
hard firing.

The composition is as follows:

Analysis of Stoneware Clay, Roberts’ Mill, Pickens Co. (No. 32 8S.)

Silica) ((COtaL) sisisvescc sents ess ego) comcemena eeu) Seales 68.23
AT UNAIN - ok gasps cee, “a'ece siesta ieudien wiacerbeennies 2 Stersietense 20.35
WElClsosi 547 REROS HHTE EER BORK ER coe 6.10
Perric! Oxide; vocc¢susdeee ees sé ceeng ere, Seay 3.20
GANG LEE eeS: GoeL Okey READY ERASE Kea B84
WASTES 1A ayaa ie acstdies sedaacdsa oom leteraanee denoguaienel eds <a aneaaiana tr.
BIBAUCS os aaedddak aadumd Hsce bhidite Berka Slane ters wkteaed se 74
MOIBCULG: craesaiet - acess pigisinsests. ostaieoune- libs Slate 1.06
100.02
Pree: Bilied (SANG) xcieeccisa —sveiwise beacons daar 43.23
Potaly NUKES: He wsS, dened maw Ga ow easels 4.28
Specific CAVITY. crcveicccteteacs, diwweacduegce ee wevinews 2.17

This clay might also serve for stoneware. . It burns to
a buff color.

In general composition this clay resembles somewhat a
stoneware clay used at Zanesville, Ohio*, which is given
below. It will be noticed however that while the per
centage of total fluxes is very close, the individal ones
differ somewhat in amount from those in the Alabama
clay.

Analysis of Ohio Clay.

Silica (combined) ......0 2.2. ...0. cece cease veeaae 25.40
ANOWUNG oui giaki, aye sey beerdeaee: Bae ase 21,13
WALGER ckotoe toate dy were imich unaek a a Hives avs 6.29
Merri¢ Oxide. iy away ee deccaa ou wh Stems’ <a pawns 1.28
TUM esl Seis | SE atowsseg Ph dts. Wane avbaeate | eee ca eae 51
Masneslatrgis ss inns ceca ates kis Mak meee hae 18
ANTICS: ed snonnncvea tian: | sale aguinGe tas sb. con 1.80
Moisture..... i RHYS bg SRN Ry GE Sendra eae Gd emaiand A caheas 1.65
99.24
Free silica (sand)........ ce. .ee cece eee ee 40.81
Total Muxes; ssicain wxaes se wate ee ds woods estate 3.77

*Ohio Geo. Surv. VII, 193.

POTTERY OR STONEWARE CLAYS. 173

(No. 11 8.)
POTTERY CLAY.

CRIBBS PLACE, BEDFORD, LAMAR CO.

A dzrk-colored, tough blue clay, containing much or-
ganic matter. It is very dense, and slakes very slowly.
No pyrite and few mica scales were noticeable.

It requires 45 per cent. of water to make a workable
mass, which was extrremely plastic and fat. This clay
shrunk 12.5 per cent. in drying and an additional 6.5 per
ceat. in burning giving a total shrinkage of 19 per cent.,
which is a large amoumt. The tensile strength of this
air dried briquette should be great, but on account of
the excessive plasticity it was found hard to mould bri-
quettes which were free from flaws, so that most of them
broke at about 100 pounds per square inch. Incipient
fusion occurs at 1900° F. Vitrification at 2100° F. and
viscosity at 2300° F. The clay burns to a deep red,
dense body.

The following is the composition of it.

Analysis of Pottery Clay, Cribbs’ Place, Lamar Co. (No. 11, 8.)

Total silica: senssecn gees Fi eee eee eee tes 60.9

Aluming.....0 cece cee cee eee cece ee nee renee 18.98

Water and organic matter .....--.- seer ee eeeee 12.46 ©

Ferric oxide :

TAMG: oi dessvarers. eto PSE BES. Berets

Magneslasicen acaenents BEESSG BORER ES

AIMKAES ica: weston wets GPEVaSR ewmeae was

MOistureisciaiwsc. cicandiien eee Sees FO0b sy seals

Free silica (Sand) .....cceeee cece e eee cane reeee 387.92
Total flUxeS ......6 cece e ee cence ce enenneee 7.68

Specific gravity ......65 cree ee cece eee eee e nee 2.313

The chief use of this clay wovld probably be as a bond
for leaner clays, in the manufacture of courser grades of
pottery, or perhaps sewer-pipe.

174 DETAILED REPORT ON ALABAMA CLAYS.

In burning it has to be heated very slowly to prevent
cracking, and the same holds true of the drying. Its
excessive plasticily is in part due to the contained organic
matter.

(No. 27 8.)
STONEWARE CLAY.

J. B. GREEN, FERNBANK, LAMAR CO,

A dense, fine grained, compact, tough clay, that falls
to pieces extremely slowly in water. No pyrite notice-
able. Taste somewhat gritty.

It required 32.6 percent. of water to make it work up,
giving a plastic mass. The shrinkage in drying was 10
per cent., and an additional 7 per cent. in burning, mak-
ing a tutal shrinkage of 17 per cent. The tensile strength
as determined by pulling apart air dried briquettes of the
clay was on the average 152 pounds per square inh with
a maximum of 185 pounds per square inch. :

Incipient fusion occurs at 1900° F., vitrification at.
2100° F., viscosity at 2300° F.

The clay burns to a hard, impervious body, of a deep
red color. There is considerable organic matter present.
in the clay, which adds somewhat to the plasticity.

The analysis of the clay is as follows:

Analysis of Stoneware Clay, Fernbank, Lamar Co. (No. 27 8.)

DITCH. ACLOTAT) ase titers s: sracdige’ lavatthignaiieila, Boe scl ohigrestanal ac ay
TAMIMING. as daca cae eae a esinesie

Water and organic matter
Ferric Oxid sss4aceen eascccedanns

METIS sy agngec sain SU aga tartans Mae aeintog® « SueGeUsbauan’. <BeGdeee euieUR Meee
MAPMESIOY :2 Gcaiicccsecasace 2) eae) Ce TeeGate) Ieee Sraeueen f
PAHO Stein d cataciy, <Sicthaneitn Se, acw, te aieoareah hg ee Ne a, BES tr.
Moisture). :scsmvicte's, bukser, Cokie Mite Gisiwapean ae 3.40
99,24
Ereé. silica (sand) ecpexecs es. comienecca caw genet 43.90
Total impurities: csiccowsway ssenwnwwe aearewes 6.65

Specific gravity ........... Se me ee 2.305

POTTERY OR STONEWARE CLAYS. 175

This clay would probably work very well for stone-
ware.

(No. 718.)
POTTERY CLAY.

W. DOTY, FAYETTE CO.

A fine grained, red clay, with little coarse grit, and
very few mica scales. Slakes quickly to fine grains. It
required 34.3 per cent of water to work it into a mass of
good plasticily, the bricklets made from it shrinking 7
per cent. in drying and an additional 6 per cent in burn-
ing, giving a total shrinkage of 13 per cent.

The tensile strength of the air dried briquettes, was
on the average; 116 pounds per square inch, with a max-
imum of 155 pounds.

Incipient fusion occurs at 2000° F., vitrication at
2200° F., and viscosity at 2400°.

It burns to a dense hard body of a nice deep red color,
which darkens as vitrification is approached.

The composition of the clay is as follows:

Analysis of Pottery Clay, W. Doty, Fayette Co. (No. 71, S.)

Silica (total) ..... cc 5c cee eee cee eee teens 65.58
AMUMINE <oscckeae wORea ee: Mie Sees: eee ents 19.23
Wiater iis: cenaduscu ce cote ae BRR eeaiahel Aiea sue ite nse) 5.50
Ferric Oxide ......05 5 cece eee teen eee e ene eenne 4.48
FANG oe ie ctermiceiece e eceeieisued aad) aOR RNS Y eae sete oor tr.
Magnesia 1... sever eee cence cere rene ceeeeces tr.
Moisture...... secccese coer ceces eaccceseccess 1.40
96.19
Free silica (Sand) 1.0.06 ceeeeeee ceceerseeenene @ 45.85
Total fluxes ....... tk GUEMNSedsd Fe Bae se ews 4.48

Specific gravity ...... cece ee cece en cee e nen 2.42

176 DETAILED REPORT ON ALABAMA CLAYS.

(No. 708.)
POTTERY CLAY.

W. DOTY, FAYETTE CO.

A fine grained, rather gritty, reddish clay. In water
it?slakes quickly to small irregular grains. The addition
of 25 per cent of water gave a plastic mass, which shrunk
6.2 per cent. in drying and an additional 5.8 per cent. in
burning, giving a total shrinkage of 12 per cent.

Briquettes of the air dried clay had an average tensile
strength of 95 pounds per square inch, and a maximum
of 151 pounds.

Incipient fusion occurred at 2000° F., and viscosity at
2400° F. The clay burns to a yellowish color at 2000°,
but to a red at 2200°. The body of the burned clay is
smooth and dense.

The clay analyzed as follows:

Analysis of Pottery Olay, W. Doty, Faette Co. (No. 70 8.)

Silica. (£6ta1) « sia.ee clases, $5045.00 MORE Bee edie 67.10
AIUMINA oo ct naGs, gate ease -saisuse bee, Senn Mestad 19.37
WREER coche. d Goe Re, aie gaara een tela AS RRR avant Mak eee 6.08
Merrie YOXIde: a :e-shee ae. evan aah Mia JeaaNeie abe 2.88
PIMC essen. cexaveiirers Cs detaieieca been aes tr.
Magnesia ........ ceeeeeee Sluis e Eeer easy 725
AIKOS cisigeie get aoa od Wea Ss bax. wae e ROE E ES -672
Moisture. sseckewe eee 448 EVP Ge. deeds eee 1.71
98.537
Free silica. (Sand) i.esccac cavec eee sae Siwe oe 43.93
Total MuxeSic sek caasinee wade Serene es 4.27
Specified: gravity: o.ci jek coesess asgeesee aaewnse 2.416

In compositon this clay resembles some-what a clay
used for pottery and sewer pipe, and obtained at Gilker-
son Ford, Henry Co., Mo.*

*Mo. Geol. Survey XI, p. 328.

POTTERY OR STONEWARE CLAYS. 177

The composition of this clay is:

Aualysis of Clay, Henry Oo., Mo.

Silledscccus dees avin aanaietew ceeacencs 67.49
AIUMING ec ss 3 aavanee VERKETANEOSGE cin daa. wees 21.11
Wateiiauecs cieyeed ee taueicis swe edioa vensauonnaniacene 5.95
Bir TiC: (OI WG yess sexadsctvscsueac Gysuedscaniesaialtne, - aysyernaiaiin iors 2.45
TRIMS siicgene Ssvesanaviagy ceed untae’ WinlasGaivanne - “estaba ease 17
Mapnes liaise: scant: ek he. 6's we wieiesl, ORpRER Cowie: HRS 63
ANALG. cas.ccihe : Gssneraricitn. Rathieseieten. latelgmnarsuhes “Gudhemuaveny oy: 2.83

100.63
Total AUKS jscieeess ween eres KeEriaa: wea ead 6.08
Specie SravitVecaven <655544% BANE Uda wee a vese 2.23

The shrinkage in both drying and burning is sx per
cent. and the tensile strength in 110 on the average, with
a maximum of 127. Incipient fusion begins at 2000° F.
complete vitrification at 2300°F., and viscosity at 2400° F.

(No. 68 S.)

POTTERY CLAY (REFRACTORY).
SHIRLEY § MILL, FAYETTE CO.

A fine grained,-compact clay, with litle coarse grit, but
considerable fine sand. Color drab. It slakes very
slowly to scaly grains.

Three per cent. of water were required to make a work-
able paste which was quite plastic. This paste shrunk
10 per cent. in drying and 4 per cent. in burning, giving
a total shrinkage of 14 per cent.

The tensile strength of the air dried briquettes showed
an average of 106 lbs. per square inch, and a maximum
of 123 lbs.

The clay burns to a yellowish white body. Incipient
fusion occurs at 2000° F., vitrification at 2200°F., and
viscosity at 2400° F., The composition of the clay is as
given below:

178 DETAILED REPORT ON ALABAMA CLAYS.

»

Analysis of Refractory Pottery Clay, Shirley's Mill, Fayette Co., (No. 08 S.}

Silica. (total) i cceaie sietesists <eeeacies ees ieeenge T2R0
AIMMINE 3 ccc 55-3 aumsisineie Seetetatecs ttuelcan sezeneae TTA
Water and 10SS.......2. sseeeees a ReLQEE ET «esi 7.40
Ferric oxide.... scccccne cae ce ee sees wn assaeree 2.40
Lime...... Die HMeeesek: wet Deed: CAR RAETAC SS trace
MAGNESIA sisi ditn ayecdne: auneo ee heane GaLgmeieep, eleeats trace
AVR OS siaiccc avaauiekrersten, akerirnedyass demandes, alee 2 56
MOISTURE) iis axes, Wee MeN Me We eeu Gee ee .12

100.10
Free silica (sand).... ...... witty Eee ShoekraRRs 52.31
Total fluxes.... ........ Sisilss <ORdavey da BBs cavereronaisn 2.96
SPeCiflie BIAVITY «06:6 vee isc, ceaveiacesaveney’ Sees s-erevecaanauons 2.28

This clay might work for an inferior grade of fire brick,
or also for pressed brick of a light color, or even for
potter’s clay. It resembles rather closely in composition
a stoneware clay from Commerce, Scott Co., Missouri,*
agreeing closely in every respect except the tensile
strength. For sake of comparison the properties of the
Commerce clay are given herewith:

Analysis of Clay, Commerce, Mo.

BU CAnwne cadiwge ig eee anadareend 6 Ryde exeess x 71.78
Alumina! vasicures alels. utaweiale WhmMeS Cesare Samsises 17.01
WALER: staicigsars adc GRAM UES auTGLR/E IES 6 Grelecereiese 8.13
DOI DRIIE Aa yeKOW Diewsetie sacs sedeneennen 2.01
TAGS ARS ae gis < mat eeinme. “adye tee eed aucrmeatalse ae .B4
MACE: Srnebasaan dbawereeas daase eeuiegumena es 43
PUES raked ieeeal «alacant wa ae ereer ew pale ew ea 78
100.48

Dotal AuXes: ycoxavissaiin ducati we aaihexueniee 3.56
Specified! Sravyity? 4 ccviwvviesuuar adaancatecrayene ae oenuaeeta 2.08
IMCIPLEME LUSION: se.jcniurainaeie. vase cietece? Guaidimataares ~2000° F.
VACHIACALON) wynadaccs, agigineeis eauobie ganas 2200° F.
VISCoslty> ccctecsiaonday, —wawk. Seca Mtastee hce feces av areade 2400° F.
Average tensile strength... ...... .. "225 Ibs. per sq. inch
Maximum tensile strength ...... .... 254 Ibs. per sq. inch

*Mo. Geol. Survey, XI, 350.

POTTERY OR STONEWARE CLAYS. 179

(No. 23 S.)
STONEWARE CLAY.
HEZEKIAH WIGGINS, FAYETTE CO.

A light gray, hard, compact clay, of moderately silic-
ious character and containing a few scattered mica scales.
It slakes very slowly to tough scaly flakes.

In order to make a workable paste the clay required
the addition of 34.3 per cent. of water. This paste was
markedly plastic. Its shrinkage in drying was 14 per
cent. and 8 per cent. in burning, giving a total shrink-
age of 22 per cent. The tenacity of the air dried mass
was on the agerage 232 lbs. per square inch with a
maximum of 300 lbs. per square inch; which is exceeded
by comparatively few clays.

Incipient fusion occurs at 1900° F., vitrification at2100°
F., and viscosity at 2300° F. The clay burns to a dense
madd body, but requires slow aa and heating to avoid
cracking.

The composition of this clay is as follows:

Analysis of Stoneware Clay, H. Wiggins, Fayette Co. (No. 23 S.)

Silica: (total): scossicuy soeiena deals Baws ea eorete eds 63.27
AIUMING gesseexs siesta eemaeee so ver wtets 19.68
Watel cueagess coiewanes SaseeaeRee ceere acts 6.05
HOM ORIUE c.ceecattoe SASH, BSES CESS 3.52
TSTEINGS etausrereccaia seve:-sr) varevai etatieie cous ave: » Sedatevershey “ese eS ASNs 1.30
MB EWOSIE. cxicce vavicw-at sdesinrnerararss suncmanmisiaiatwcel: seve abe ceece tr.
B00: 0:1 ee ee eee ee 1.20
MOIStUIC: 2 ¢s-ser6ieis-s Bae ce eee RR TE Re eee 8 ere 3.75
98.77
Free silica (sand) «++ e+e sees cee ene co eenans 89.59
Total fluxeS ...cc0e secvccee cosces coccsevvece 6.02
Specific gravity .....eee oe eiereleiere:e) 9:00 isieib:e'e's sajers 2.32

The clay agrees in composition in a general way with
some of the stoneware clays of Missouri and Ohio, and
its shrinkage and tensile strength are similiar to a ston

180 DETAILED REPORT ON ALABAMA CLAYS.

ware clay from Harrisonville, Cass Co., Mo.,* but the lat-
ter having nearly 3 per cent. more fluxes fuses at a lower
temperature.

(No. 65a. S.)

POTTERY CLAY.
TEN MILES SOUTHEAST OF HAMILTON, MARION CO.

A moderately gritly, medium grained clay with a few
mica scales, it required 28.9 per cent. of water to make a
workable mass, which is rather lean. The air shrinkage
of bricklets made from this was 6.5 per cent. with an
additional shrinkage of 5.5 per cent. in burning, making
a total shrinkage 12 per cent.

The average tensile strength of air dried briquettes
was 58 lbs. per sq. inch with a maximum of 6.5 lbs. per
square inch.

Incipient fusion occurs at 1950° F., vitrification at 2150°
F., and viscosity at 2350° F.

It burns to a grayish buff color.

The chemical composition is as follows:

Analysis of Pottery Olay, 10 miles southeast of Hamilton, Marion Co.
(No. 66a, 8.)

Silica (total): -++++e sescescesces sonnecescsenes * 70.00
AIMIVING. ci viwheee 42445805 Sa4iderene Shewew ow 21.31
VRIES .decdesna Sas intake Siar eenne Leoeasaes 6.35
MELPIG: OXIGE: ois sevevaveicinte, soled dco wes biekere, “Oseieeiee's! iiepsie tev 2.88
DUBE sxcasces near enae Meagae es S2ee eke RECCES -20
MIGSNCR Mawes SAKE RNSOS KERRIER Bee tr.
AILGNOS as csceee eaeoendedaw ExeRwwew 24 ed c24ERe tr.
MUStUPE cacecndiece SPEINE ED eensaneeaae eane -50
101.24
Free silica (Sand)+-+-+ ssseseseeeee oe we eeeee oe 45 80
Total \AUECS: sess wary eee ee. Ses orawemiakie garemioulan 3.08
Specific eravity scnawaws sseesemen seaceis wewees 2.10

*Mo. Geol. Survey XI, p. 315.

POTTERY OR STONEWARE CLAYS. 181
(No. 62 8.)

POTTERY CLAY.
THOMAS ROLLINS, FRANKLIN CO.

A fine-grained tough clay, which slakes very slowly
when thrown into water, but splits very easily along thin
sandy layers which occur at intervals of about every
half inch, a few mica scales are present, the addition of
20 per cent. of water gave a workable and quiet plastic
paste.

The shrinkage of bricklets made from this paste was
10 per cent. in drying, and 4 per cent. in burning, or a
total of 14 per cent.

The average tensile strength of air dried briquettes was
102 lbs.per square inch, with a maximum of 127 lbs. per
square inch.

Incipient fusion occursat 1900° F., vitrification at 2100°
F., and viscosity at 2300° F. The clay burns to a red-
gray, but has to be heated very slowly,

The composition of the clay is as follows:

Analysis of Pottery Clay, Thomas Rollins, Franklin Co. (No. 62, S.)

Total silica ...... ccccccces ceanenece connesece 67.50
GMIOd wekuker aes Seen otaew uses aiadwate ls: TROIS
Wate Gtacese Baetehess COP2Se gasetees eae yee 6.15
Ferric oxide 6.15
Lime .12
MagneSia ...... ccc ee cee eee ree tee ee eteeee 10
IMOUStUTE® seis: upk aie es Baleares RS CRAG ele eee Joe Re 1.50
TOCA) citarseeesan 2 Feiiagiewais see Bee ae 100.97

WIGS. (GANA es fdeee eh yee B44 He ST Ew eS 43.46

Pere TON co) ces tabs eaten. vssecoo eo 5.80
Speeifie gravity <.2.ecesae @4as KERR ESE BEN EH 2.36

(No. 55 S.)
POTTERY CLAY (REFRACTORY.)
J. W. WILLIAMS, PEGRAM, COLBERT CO.

A white clay of fine grain, which slakes easily in water.
The addition of 26 per cent. of water gave a lean

182 DETAILED REPORT ON ALABAMA CLAYS.

workable mass which shrunk 5 per cent. in drying, and
10 per cent. in burning, giving a total shrinkage of 15
per cent. The average tensile strength of air dried
briquettes per sq. inch is 30 lbs, and the maximum ten-
sile strength per sq. inch is 35 lbs.

Incipient fusion occurs at 2150 F., vitrificataon at 2300
F., and viscosity at 2500 F.; the clay burns to a dense
yellowish white body.

Following is the composition of the c'ay:

Analysis of Pottery Clay J. W. Williams, Pegram, Colbert Co. (No. 55 8.)

Total silica 2.2... 605 cece cece ee cee ween nne 66.45
AIUMIDS. ccccncwici Lec ese ee Gee eee ESS 18.53
Ferric Oxide ......... ceenseeens ceereeeceecee 2.40
Water ccceewg sia cwsiedar Sense yori: iecialiece diene 8.68
LiMe: cacsee4ek WEN RARE wee Seslee eee ee aula S 1.50
MaPNGSia. wwe cisiiee esas hee cae easemies gyeeisreee 1.25
AIKGNIES siege Poses ee MERTSENE Gata Megas vaes tr.
IMO@IStULCS ainciedey Bidens “heute Spe eusae LSAG SES Be -78
99.59
Free silica (sand)........ ....e% Utes Wis Maeda aa 44.22
Total MUKES) jo jaid S ioxe seanties! eae ease Gl evisu) sates a 5.15
Clay: DaSC. eeees can cae woused ae dal Sdigdiy enemies 49.44
Specific @ravity’ 22.6 s+euew Av geese Ga we dees ew ew 2.39

This clay could probably be purified by washing, it
corresponds in general composition to a fire clay from
Parker and Russel’s Mine* near St. Louis Mo., but the
latter on account of its greater coarseness, has a larger
refractoriness.

BRICK CLAYS.

The term brick clays is a somewhat elastic one for it
may include those used for the manufacture of common
brick, front or pressed brick, and paving brick. As the
requirements are somewhat different they can be men-
tioned briefly and apart.

Clays for common brick. For this purpose almost any

+*Missouri Geol. Survey. Vol. XI, p. 570.

BRICK OLAYS. 183

clay suffices, in fact so little attention is applied to
material used for this purpose, that the product is often
soft and porous. Clays for common brick should not be
excessively sandy, otherwise the brick will be weak and
porous. They should possess sufficient plasticity to mould
without cracking, but not be so plastic as to warp, due
to excessive shrinkage. Most brick clays burn red. Fer-
ruginous clays can be more safely burned to a hard pro-
duct than clacareous ones, which burn buff or cream

colored.
The methods used for moulding common brick are the

soft mud, by which the soft plastic mass is forced into the
monld; and the stiff mud, in which the clay is forced from
a die of rectangular cross section and then cut up into
bricks. The latter method gives greater capacity, but
the bricks unless thoroughly burned will not stand the
weather as well. Very plastic clays and very lean
ones are adapted to the stiff mud process, the former be-
cause they are not tenacious enough, the latter because
owing to their pastiness and the structure of the machine
a laminated structure is developed in the brick.

Brick clays should have a tensile strength not less than
50 lbs. per square inch. They are not required to stand
a high degree of heat, a few common brick kilns attain a
temperature of over 1800 or 1900 degrees Fahr.

The more rapidly the clay slakes the easier will it be
to temper it.

Clays for front or pressed brick. For this purpose a
lighter grade of clay is required, and the material must
not only burn toa hard body but also to a uniform
color, for on the latter depends much of the beauty of the
structure. In no branch of the clay working industry is
the range of colors producible from natural clay mixtures
more carefully considered than in the manufacture of
pressed brick.

184 DETAILED REPORT ON ALABAMA CLAYS.

Many shades are obtained either by mixing two or more
clays, or by adding artificial coloring agents to the raw
materials.

Clays for front brick should shrink evenly in burning,
and not warp nor crack. Straightness of outline and
evenness of size are essential to close fitting when set in
the wall.

Many front brick are moulded by the dry-press process,
in which the clay is forced into the mould in the form of a
dry powder. Such bricks have straight edges and smooth
surfaces, but unless burned good and hard they chip
easily. At many localities the clay is moulded in soft mud
or stiff mud machines, and the brick, while still soft, re-
pressed in a second machine whereby the surfaces are
smoothed even and the edges straightened. These lat-
ter brick do not tend to exhibit the same brittleness along
the edges as the dry press brick are apt to.

Front brick sell from $15.00 to $70.00 per 1000, de-
pending on the color and shape.

Clays for paving brick. The naturé of these must be
such that they can be burned to vitrification. To do this
economically and on a large scale the points of vitrifica-
tion and viscosity should be at least 125° F. apart and
preferably 200° F. If they were not it would be impos-
sible to bring a kiln full of bricks to vitrification without
running them up to the temperature of viscosity. For
this reason calcareous clays are not well adapted to pav-
ing brick manufacture.

Paving brick clays should possess moderate or good
plasticity so that they can be moulded by the stiff mud
process, and while it is desirable that the tensile strength
should be 75 pounds or more, at the same time many
good paversaremade from mixtures whose tensile strength
is not over 50 pounds per square inch.

Shales are used to a large extent for the manufacture

: BRICK OLAYS. ‘ 185

of paving brick, partly because many of them contain
about the right quantity and kind of fluxing impurities,
and also because, owing to the fineness of grain, they vit-
trify more evenly and thoroughly.

Paving brick are at times made from fireclay, and the
results obtained are excellent, but still shale isthe favored
material.

Except for comparing brick made from the same
deposit, the color is absolutely no indication of the quality
of a paving brick. ‘

The important properties which a paving brick should
show are low absorption (under 2 per cent.) and resistance
to abrasion. Crushing strength is of little importance
provided it exceeds say 8,000 pounds per square inch.

The brick clays described below come from several
geological formations. The Graves’ shales, Nos. 107 and
108 ; the Coaldale shale and the Pearce Mill shale, No. 3,
are Carboniferous shales. The Dixie clay and No. 128
and 129 of Mr. Stevens, are from the Poleozoic limestones,
while the rest, No. 110 from Shirley’s Mill, No. 122 from
Chalk Bluff, Elmore Co.; No. 126 of Mr. Stevens, from
Woodstock ; No. A, from Tusealoosa Co., are from the
Tuscaloosa formation of the Sower Cretaceous.

(Nos. 107 and 108.)
BRICK-SHALES.
W. H. GRAVES, BIRMINGHAM, JEFFERSON CO.

Associated with the coal on the property of Mr. W. H.
Graves are two beds of shale, viz: a yellow, sandy shale,
and a gray one containing much less grit. Both of these
were tested physically and the results of these tests are
given below. The yellow shale contains a high per cent-

186 DETAILED REPORT ON ALABAMA CLAYS.

age of ferric oxide and fuses very easily, while the gray
shale contains several per cent. less, and is much better
adapted to the manufacture of vitrified wares. The com-
position and physical characters of the two are given side
by side for the purposes of comparison.

Light or gray shale, No. 108.

Plasticity, quite good. The shale takes 25 per cent. of
water to work it up.

Air shrinkage 2 per cent.

Shrinkage at 2000° F., 9 per cent. Brick good red
color not, very porous.

Shrinkage at 2200° F., 12 per cent. Brick reddish
brown, and just about vitrified.

Fusion a 2500° F.

Tensile strength—average 105 pouuds, minimum 85
pounds per square inch.

Dark or yellow shale, No. 107.

Plasticity moderate; shale gritty, requires 20 per cent.
- of water to work it up.

Air shrinkage 14 per cent.

Shrinkage at 2000° F., 5 per cent. Brick good red
color. Somewhat porous.

Shrinkage at 2150° F., 63 per cent, Brick nearly
dense, reddish towards brown.

At 2250° F., nearly vitrified.

Fusion at 2500° F.

Tensile strength only 40 pounds to square inch.

Analysis of shales, Birmingham, Jefferson Oo. (No. 107 and 108.)

(108) 107)
BIICA. oss eeeee 244 050REe 4X4 eecee ako 57.80 61.55
ANU ae -bukdo backed eens. aaeend 25.00 20.25
Ferric oxide ...... ssccee seveee soe 4.00 7.23
TAME -ptaew $IBRAaee Adeeex) Wawad aaa 2.10 tr.
Magnesite csvisacas “usaeq. KA RRs KEKE 80 -986
Pepi wav dew Weng Sade Kexeae “ae 7.50 6.19
Alkalies: ccs eu aesass mage ged caarewtign 1.80 2.25

99.00 98.466
TOtal: MURGS! seas. aiiacsdeiet ss 2a esas 8.70 8.45

BRICK CLAYS. 187

. The gray shale burns to a denser, harder body than
the yellow, and does not blister as easily in burning ow-
ing to its lower per centage of iron.

PAVING BRICKS SHALE,

COALDALE, ALA.

A yellowish red, soft shale, with considerable grit. No
mica or pyrite noticeable.

Ground to 80 mesh and mixed with 22 per cent. of
water it gave a lean paste, which shrunk 4 per cent. in
drying and 5.5 per cent. in burning, giving a total shrink-
age of 9.5 per cent.

The tensile strength of the air dried briquettes was on
the average of 25. pounds per square inch with a maxi-
mum of 35 pounds.

Incipient fusion occurs at 1900° F., vitrification at
2000° F., and viscosity at 2150° F.

The shale burns to a red body and makes a good red
brick. It is also used for paving brick.

(No. 33.)
RED SHALE,

PEARCE’S MILLS, MARION CO.

There is an an extensive outcrop of partially weathered
Carboniferous shale along the private road of Mr. Pearce
just before reaching the millls. It is a red, rather fine
grained material, and contains a small amount of mica.
Its soft character renders the mining of it an easy
matter. When ground the shale gives a moderately
plustic mass whose plasticity could no doubt be in«reased
by weathering. Forty per cent. of watcr were required to
work it up, and the bricklets made from this material had
an air shrinkage of 4 per cent, When burned tv 2000°

188 DETAILED REPORT ON ALABAMA OLAYS.

F., the total shrinkage wus 8 per cent., and the color of
the bricklet was a rich red. At 2100° F., the color of
the bricklet was the same, and the shrinkage was 9 per
cent., incipient fusion having occurred at this point.
Vitrification occurs at 2200° F., and the color is deep red,
while viscosity took place at about 2300° F. In drying
the clay showed little evidence of containing any appre-
ciable quantity of soluble salts that would tend to form
any efflorescence, nor did any show themselves afetr
burning.

The comparatively small shrinkage and the rich red
color to which the clay burns would make it ad-
mirably adapted to the manufacture of pressed brick, but
unless it was mixed with a more plastic clay it would
hardly work for the production of terra cotta.

The semi-weathered character of the material would
also facilitate the preparation of it.

(No. A.)
PAVING BRICK CLAY,
TEN MILE CUT, TUSCALOOSA Co.

The sample of this clay was collected by the writer
from what is known as the Ten Mile Cut on the M. & O.
R. R., west of Tuscaloosa. It is a somewhat gritty clay,
which contains thin seams of sand. The general color of
the clay is bluish-gray, but here and there it shows stains
of limonite especially on the sandy fractures. When
thrown into water it shakes and gives in working a some-
what gritty, but quite plastic mass, which requires 26.00
per cent. of water to work it up.

The air shrinkage of the clay amounted to 83 per cent.
while at 2200° F., it was only 10 per cent., and at 2300°
F., 12 per cent., at which point incipient fusion occurred.

BRICK CLAYS. 189

Vitrification took place at cone 27 in the Deville fur-
nace and fusion above cone 30.

The tensile strength of the air dried briquettes varied
from 126 to 144 pounds per square inch with an average
of 140 pounds. The clay burns toa buff color, and is
to be classed as a refractory one although it is not highly
so. Its location is excellent for cheap working, and easy
shipment of the product, and while it has been put under
the head of paving brick clays there*is no reason why it
should not find uses in other directions as well.

The chemical composition of this clay is as follows:

Analysis of Paving Brick Olay, Tuscaloosa Oo. (No, A.)

Silles. cocky Seeweacdeaw Ce evEREORe Ged EEO 72.70
ANUDOUINS. aicuwideaa sae Sige tetas as eT wees ea ce 19.61
Frerric oxide .....cc00 ccc eccee cecernee vesees 934
Alkalies ... 0... cc cece ene tect nene teen eee .80
Ignition 0.6... 0 ccc cee eee cee eee eens cee e eens 6.50
100.544
Total fluxes ......06 cececcce serene nscenseues 1.734

PRESSED BRICK CLAY,

DIXIE POTTERY CO., OXFORD, CALHOUN CO.

This is the clay used by the Dixie Tile and Pottery Co.
For the manufacturer of buff brick, the clay is quite plas-
tic, and considering this fact it does not seem to require
an extraordinary amount of water to work it up. The
amount used being only 25.75 per cent. The average
tensile strength is 130 pounds per square inch, with a
maximum of 144 pounds. In air drying the clay shrunk
about 10 per cent ; at about 2200° F. incipient fusion be-
gan, and up to this point the clay had burned a buff color
but then began to burn toa grayish tint; vitrification took
place at 2400°, and the total shrinkage to this point was

190 DETAILED REPORT ON ALABAMA OLAYS.

18 per cent. The clay fused or became viscous at 2600°
F. The following is a composition of it:

Analysis of Pressed Brick Olay, Owford, Oathoun Oo.

MSLHCAL -susichsvsiare\ awl Melalaravalel. alee @aiareis. (Sle weiareniy, Nees eye 71.30
AIIMING: ccc cavss waceies 2eee dee Ceara aageeaes 17.16
HEPC Oxid@csost.. 2ocbsase act@ien teem cae ss 1.94
PATNA G avieasyduay er Subse awed Ge te Guanes abt an ~ereubueers TaueGoe aneHeterieh ere 60
MagneSid > ives wia sieve aeRgrereckc « Sraxncamvatene Guae Seeunmaecalc 43
AUK BOS: ssescsccsceneas x cresecier ewadtes Ad aveeaxereina ene oa) 95
TONIC canetscctceer Ghebweiive Nee iesieey'e Ristakes Gealensiinas vos 7.60
99.98

TOtal: MUXES: susiacige Sitiwestee cg oa: sce Soe Ree RGM Ge Sie Be 3.92

This clay should make a good buff colored ware if
burned at a comparatively low temperature, but if burned
to vitrification the color would of course be much darker
as indicated by the test, and owing to the high shrinkage
in burning it would be necessary to conduct the latter
slowly and with care to prevent cracking of the clay.*

(No. 110.)
PRESSED BRICK CLAY.

SHIRLEY’S MILL, FAYETTE CO.

The clay from this locality is a very fine grained dense
one, but at the same time breaks up very easily.

It took 33 per cent. of water to work it up, and the air
shrinkage of the bricklets was 6 per cent.

Incipient fusion occurs at 2100° F.

Vitrification took place at 2200° F. and at this point,
the bricklet showed a total shrinkage of 16 per cent., and
a deep cream color.

In the Deville furnace, at cone 27, the clay became
viscous.

*These bricks are well known in Alabama, and deserve to be even more
generally usd than they are. E. A S.

BRICK CLAYS. 191

While this clay is not to be looked upon as a refractory
one, it would seem that owing to the beautiful color, to
which it burns, it would be highly desirable for the manu-
facture of pressed brick.

The composition of the clay is:

Analysis of Pressed Brick Clay, Shirley’s Mill, Fayette Co. (No. 110.)

iCa. sass} Waemieletvicde caeieredahianndual oe eadnGisunee. 26 71.32
AVUMING: tek aeNers aca ite! eeeckieeien ieee) Waa Se ae 20.10
MOWING BG: cacaciry Ketsabeees 6oeaeteeedanas a 1.05 ?
DG een pak THe RP Oe VATA stan SRN eu a ees tr.
Magnesia: «s/ia 5 tide Sie aca a 5 Ab Gaharescianaieace hoo 2's aed .3816
AUKANOS ks mniiposia ag eine eben area a ataiis RAR Uetee tr.
IZMIVON w.s0iCiwie ai ausieuess 3 amehGr Leeane eee 7.505
100.291
Total HUSEs sseane aeeve «eaves oowaevee s4ae4s 1.366
SPECING SrA VIE: ss Mesias vent Cikvspetics eereeas Maeve 1.90
(No. 122.)
BRICK CLAY.

CHALK BLUFF, ELMORE Co.

The upper half of the clay bed at this locality is com-
posed of a dark, dense, grayish brown clay which contains
a large amount of organic matter, either in a finely divided
condition or iz the form of leaves. Although not sandy,
at the same time it is rather lean when mixed up with
water, and owing to the presence of so much organic ma-
terial absorbed 40 per cent. of water when it was being
worked up to a plastic mass. The air shrinkage was
however only 6 per cent. At 1900° F. it had reached a
total of 14 per cent., but the bricklet was still very ab-
sorbent ; at 2100° F. incipient fusion had been reached
and the total shrinkage was 18.7 per cent., while the
color was brownish red; and at about 2200° F. the total
shrinkage was 20 per cent. and the color brown, and this
color had deepened considerably at 2250° F. with the ap-.

192 DETAILED REPORT ON ALABAMA CLAYS.

appearance of vitrification ,while the maximum shrinkage
amounted to 21 per cent. Viscosity was obtained in the
Deville furnace at cone 27.

This clay therefore shows an appreciable and safe dis-
tance between vitrification and viscosity. The tensile -
strength is however low, averaging 75 pounds per square
inch, with a maximum of 97 pounds per square incb,
and a minimum of 68 pounds. Specific gravity, 2.41.

(No. 26 A. Stevens.)
BRICK CLAY.

WOOKSTOCK, BIBB CO.

This is quite a plastic clay, which requires 29 per
cent. of water to produce its maximum plasticity. The
air shrinkage was 6 per cent., and the average tensile
strength was 101 pounds per square inch, with the max -
mum of 104 pounds. The fire test gave the following

results :
At 2250° F., theshrinkage 10 per cent, clay incipiently
fused, color buff.
At 2400° F., shrinkage 11 per cent., color a dark buff.
At 2500° F., clay vitrified, color reddish.
Viscosity occurs at cone 27 in the Deville furnace.
The composition of the clay is:

Analysis of Brick Olay, Woodstock, Bibb Oo. (No. 186 A. Stevens.)

SUlCd.. esas cea asnsine Sa kaand eeaeee wee sews 74.20
ANUMMING, adik A-snect der Gat Seiucitien ee Siineisptielies vote wacerane 17.25
WOLrriCOXIGE: said jsvaunion seiasdedeaw oon “anoatevereeea a. carmen 1.22
MUI’: eccsies cea toe vo tae “Say avavensialeceie,. “iaiwie ws erenaleet,> fecsvevecannters 30
Magnesia. \dicisiic sie: wakes: wieeiie eee deed eeu ave .40
ATKANCS! csascin shantiewed Sessuubaie eiverve sss tr.
TSQIOU fecevaxydeee SOXNUEEAE BKRWESeE Go add dS 7.35
100.72

Total AuUKeS 6 awieiesscsie a ie Sa ON Ma? owiehe, Verve eae 1.92

BRIOK CLAYS. 193

(No. 129, Stevens.)
BRICK CLAY.

BIRMINGHAM.

This isa very dense hard clay, which required con-
siderable grinding to break itup. The difterent lots were
mixed up, and the one, A, being composed of two-fifths of
the clay which was passed through 20 mesh sieve, and
thee-fifths of particles greater than 20 mesh.

The second lot, B, was made up entirely of that which
had passed through the 20 mesh sieve.

Both lots gave a rather lean mass, but A required 19
per cent. of water and B 16 per cent. to work up. The
average tensile strength of A is 12 pounds, and that of B
35 pounds. The air shrinkage of both was 4 per cent.

In burning to 2300° F. the shrinkage of A was 3 per
cent, the color of the bricklet a full yellow, and the body
very absorbent. At 2400° F. incipient fusion occurred in
both cases, and the color of the bricklet was a brownish
gray, and the total shrinkage 10 per cent.

At 2500° F. the clay was vitrified, of a dull brownish
gray color, and showed a very homogeneous fracture.

Viscosity occurred at 2700° F.
The chemical composition of the clay is:
Analysis of Brick Clay, Birmingham. (No. 129 Stevens.)

Silica

Alumina

Ferric oxide

Lime

MAZMESIA. ainaineece airatewmeiew Beside 6 6 Sela oernteie tr.
AVR AN OSt a ieniisrasenays: “re accdeidiecbitece jevaccneucitaliny, (te oeeeveaauent tr.
Penton sac es cua apianees 4 vies Nien, Bee 9.25

MOta le DWEOS: «araicinciejaseters oc; (ob ceearinanie lata bia ela si sett gusdare 100.42

194 DETAILED REPORT ON ALABAMA OLAYS.

(No. 128, Stevens.)
BRICK CLAY.

ARGO, JEFFERSON CO.

This was a very plastic smooth clay, which took 22.20
per cent. of water to work it up. The tensile strength
varied from 120 to 136 pounds per square inch. Theair-
shrinkage was 7} per cent. The behavior of the clay at.
other temperatures was as follows:

At 2250°|F. the shrinkage was 12 per cent., color yel--
lowish gray.

At 2300° F. the shrinkage and the color the same, but.
incipient fusion had begun.

At 2500° F. the clay was vitrified, and the total shrink-.-
age was 14 per cent. In the Deville furnace, at cone 27,
the clay became thoroughly viscous.

It could not therefore be called a very refractory clay,.
but would work no doubt very well for pressed brick or-
for other purposes.

The composition of the clay is as follows:

Analysis of Brick Clay, Argo, Jefferson Oo. (No. 128 Stevens.)

SUICE. ciccgsiiaiete: aeasloduleie BEE s24e4e) Wastes 72.87
AIQMIMS o440ueueede S690 Re HEAGAd VERS RROD EY 18.03
Ferree OFIGE suscaixs enaadnse Sae8eSe Gahowdawe _ 2.00
TAG gee ere: Vaaeks Gee Re GE ENSRA ER Se 61
MS SMOBI Ao sis secpeusiiar austivanepinaesd te. Gnatnenoive ey Cain duhiaeer’ 42
BUNGE cs eat eR RAG DOEAOADIRR A BROLH RES 58
SENG acini) Ske epeteee GiNn eee ide Beuaae s 6.62

101.08
Total WU568 vssenesw Bev eueaan ECR RHRaAe GEE ROR 3.56

MISCELLANEOUS CLAYS.

These are all derived from the Tuscaloosa formation of”
the lower Cretaceous. :

MISCELLANEOUS OLAYS. 195

(No. 67 8.)
CLAY FROM W. D. BAGWELL’s,

SEVEN MILES NORTH OF FAVETTE COURT HOUSE, FAYETTE CO.

A gritty clay, that slakes slowly but completely to fine
grains.

The clay required 28 per cent. of water to make a
washable mass, which was slightly plastic and gritty.
This paste shrunk 6 per cent. in drying and 3 per cent. in
burning, giving a total shrinkage of 9 per cent.

The average tensile strength of the air dried briquettes
was 45 pounds per square inch, with a maximum of 53
pounds.

Incipient fusion occurred at 2100° F., vitrification at
2250° F., and viscosity at 2409° F.

The clay burns to a deep buff color.

Its composition is as follows :

Analysis of Clay from W. D. Bagwell, Fayette Co. (No. 67.8.)

Silica. (total) 2.% access Davewee oscar 15.70
Alumina ......655 cece teee ceeccacens os 14.36
WAteE: scbitiesy Giese s. Syuveetide:! Sees 4.45
Blerric Oxide) sc.cc5 2 Sack wae tetaewe etawaes 4.64
TAMING! os siayetier siscane Qe aio aed. eevee Geonbe ele erareed tr.
Magnesia .......2 seccnne secnccee sevaceceres tr.
Moisture: aseeveck Sepsis Heriimenweee aimee 1.24
100.39
Free silica (Sand) ........605 ceeeee coneneeenee 58.60
PER AUKER cvacisswa Kavaesarere seweceese wore 4.64
Specific gravity .....6- se eeee cece rene ceneeees 2.26

(No. 40 8.)
CLAY FROM H. PALMER,

BEXAR, MARION CO.

A gritty, fine grained clay, containing scales of mica,
which slakes easily and quickly to irregular grains.
It required 26 per cent of water to make a workable:

196 DETAILED REPORT ON ALABAMA CLAYS.

paste, which to the feel was very slightly plastic and it
tasted gritty. In shrinkage in drying was 6 per cent. and
3 per cent. in burning, making a total shrinkage of 9 per
cent.

Air dried briquettes of the mud had an average tensile
strength of 66 pounds per square inch, and a maximum
tensile strength of 68 pounds per square inch.

Incipient fusion occurred at 2000° F-; vitrification at
2160° F. and viscosity at 2300° F.; at 2000° F. it burns
to a buff, but on retrifying it becomes red in color.

The composition of the clay is as follows:

Analysis of Clay, H. Palmer, Bexar, Marion Co. (No. 40 8.)

Silica (total) ..... his dese usnah! sate patronage ethene saree 71.33
AIUMING..ccseies cakes bv desea ne been ss near ¥ 6 21.88
Water aiincerads 2445848 see ues stew ase AS ERB 5.54
HWOPriC OXid6 wads ag ose ecwaiin oe ties VoaeasT ys .82
TAMING, cei ecsicsusiiiondl oe. Yorhad Giideghecetgarel cee ghucduaurner eee Baas ane -234
MASTICSI Gs is:¢.d:ec0> Vere-suebiidis” ayaa as SAO RAC slaweuavea tee .3805
MGISHUTG! tas canbe ht aw ee! Maledne dare dulecaneen ss 1.05
100.659
Frée: silica. (Bad) ais aasrawey Gas esis bal Sidineenwes 46.45
IUCN sak aadad eter See hems, Burne ee ey ae eae -859
Specifit gravity saccsse0e sseciwan sis nudiowexnes 2.305

(No. 12.)
CLAY FROM H. PALMER,

BEXAR, MARION CO.

A fine grained clay, with sandy laminae and mica
scales between the layers. It slakes slowly to fine particles
and grains of sand.

The clay required the addition of 31 percent. of water
and gave a moderately plastic mass, that shrank 5 per
cent. in drying and 3 per cent. in burning, making a
total shrinkage of 8 per cent. The briquettes made from
this paste had, when air dried, an average tensile strength

MISCELLANEOUS OLAYS. 197

of 85 pounds p-r square inch, with a maximum of 89
pounds per square inch.

Incipient fusion occurs at 1950° F., complete vitrifica-
tioh at 2150° F., and viscosity at 2350° F. The clay
burns toa yellowish red body.

Its composition is as follows:

Analysis of Olay, H. Palmer, Bewar, Marion Co. (No. 12)

Total BUiGa ya sate Acace dis asaiiee istraee ee aavenos 69.93
AIUMINGeseeces Ganeenee’ we Qoewnwne «aaweave 20.15
Waterones ist sasagwiaaat. coeigeniidls Mawes denen 5.90
Merricoxide: scviaics. scenes: eavauale eahyirs wares « 1.38
TATAG sestmiscaveceten “6: eidiote wteraeal calaturae ee: Sx se Aecsoveeens 42
Magnesia as cscsrvac. Gieiraweale aoa ace osc tr.
Alka leit osioee, Ra caedea Mer eee A ule oxierenbee tr.
MOIStUICs scisies aida ota tldkcndd Sax secnacs seceane 1.20

98.98
TOCA URES) vcd soi. ssoaietavececmnde caterer seen 1.80
SHOCiMe STaVIEV i. pe ccuG. Gvaaunee Gua aoe qeenir colvive 2.28

(No 41 8.)

MOTTLED CLAY.

BEXAR, MARION CO.

‘A very open grained, sandy clay, with scattered scales
of mica and occasional iron stains. It slakes very
quickly to its component mineral grains.

It required 39 per cent. of water to work it up. It is
slightly plastic, and shrunk 6 per cent. in drying with
an additional 11 per cent. in burning, making a total
shrinkage of 17 per cent.

Air dried briquettes of the mud had an average ten-
‘sile strength of 15 lbs. per square inch, and a maximum
of 80 lbs. per square inch.

Incipient fusion occurs of 2000° F., vitrification at 2150°
F., aud viscosity at 2300. The clay burns to a red, but
not very smooth body.

The clay analyzed as follows:

198 DETAILED REPORT ON ALABAMA CLAYS.

Analysis of Mottled Clay, Bexar, Marion Co. (No. 41 S.)

Silics. Clotal) cereecck Gp oiwkee Soenee Reames 72.40
AVMMING, sccscciensicic Sdcereiariere es ewes aeverieneiw” éosheueverw 14.86
Waters cisuersiens; “vie Siecpcarsteie a astenerevenne ecareterevapemuess 5.05
Ferric oxide ......... ses, oe beer eee e ee eeeee 7.64
TAME) saicisanaew sigrccesccepeiaieieiers seuesstdieyenenas er sei srersieeine -20
Magnesia .......00 cen evee coeereeresees caneee -40
Moisture .....0505 cccccevs cacvcsene soeseccee -65
101.2u
Free silica (sand) ....... ceeceeee ceenee eevee 55.20
FU Z0Gs 5: cesesverscce ares eee: aiera asic awe opie ei 8.24
Specific gravity ...... ccccoe cocecsee cesereace 2.445
(No. 18 8.)
BLUE CLAY.

THIRD CUT NEAR GLEN ALLEN, MARION CO.

A very fine-grained soft clay with little grit, which
slakes very readily on being thrown into water.
}. It required 28 per cent. of water to make a workable
mass which was slightly plastic. The shrinkage of this
paste in drying was 8.3 per cent., and in burning 7 per
cent., giving a total shrinkage of 15.3 per cent. The
tensile strength of the air dried briquettes was 56 lbs.
per square inch on the average, with a maximum of 65
Ibs. per square inch.

Incipient fusion occurs at 1950° F., vitrification at
2150° F., and viscosity at 2350° F.

The clay burns to a light bluff.

The composition on analysis was fuund to be as follows:

Analysis of Blue Olay, R. R. Cut, near Glen Allen, Marion Co. (No. 18 8.)

Silica (total): +++ +e cee ese ece cee ee see ceneesanees 68.10
AlUMING. acewesce duane. Wicauetee sy: Seetaw he 21.89
We itnGa KES Eee Sed Obs ekeEls REM eaedaeR 5.05
MOITIC. OXIDE: scissor copes. aserevareree aids duseear andere oe 2.01
Lime ...... Nive avin tbpabeveWerisrahien | oneytacebieh evanist. Lohetebebisysaanatev'ehy .80
MAQNOSIA: sists oi eine Avge SSeS eee aR ORES Ow .28
Alkalles .cccccccs covescscse svvvccccs 40
Moisture: secu onasees: ee ucnd Seas Eh ewe Rees 70
99.230
Free silfea (sand) .... ccc ceee cone evere eneaee 41.60
Total sicvean «55304 s6aa0 See EReSw Gewese eeesie 4,19

MISCELLANEOUS CLAYS. 199

The fineness of grain is probably accountable for the
low tensile strength and comparatively low temperature
of vitrification and fusion. As far as the composition is
concerned it is not unlike some of the potters clays used
it the United States, but its low tensile strength would
probably act against its utility for this purpose, unless
mixed with a more plastic clay. For building materials
it would no doubt work allright. Being of fine uniform

grain permits the production of a very smooth surface on
the ware.

(No. X. 8.)
CLAY FROM W. J. BECKWITH’S.

COLBERT CO.

A moderately fine-grained, homogeneous, brittle, porous
clay, with a semi-couchoidal fracture. In water it slakes
slowly to particles mostly under one-sixteenth inch in size.

When mixed with. 28 per. cent. of water it gave a lean
mass of somewhat gritty feel, which shrunk 5 per cent.
in drying and 6 per cent. in burning, or a total shrink-
age of 1] per cent. The clay had to be dried and burned
slowly to prevent cracking.

Air dried briquettes made of the mud had an average
tensile strength of 22 lbs. per square inch, and a maxi-
mum strength of 38 lbs.

Incipient fusion occurs at 2050° F., vitrification at
2250° F., and viscosity at 2450° F.

The clay burns to a deep buff body, and requires care-
ful heating to avoid cracking.

An analysis of the material gave the following results:

200 DETAILED REPORT ON ALABAMA CLAYS.

Analysis of Clay, W. J. Beckwith, Colbert Oo. (No. X 8.)

Bilicd. (t0tal)sacy veeees bo seaew Sweeeeis aoewwe 58.20
AIUMING. sc. .a04 wives mesewe ae SR RT OME Oe 29.86
SWIREOR? occ seasstuee geaeisl-gieed ioe, avis veuph sb onaelsen’ ca sane aces SvedGos BLES 9.12
Magnesia........ > aiataohyalade , “akayiviug salauet est “eaaeee se preee aes SEES
TAME ssp ce ceeicun wma ware eaie meted aseaie wis se eunadnave .20
Plerric: Ox1d@) io so noes ergahsheiewecoar “ataniiobiniansess attain 2.22
AVEANES? jc sice verre Geiss pe eles reegwaee sy pw ets, tr.
Moisture ........ a eave ices on: Bienaus/evekattnl~ cis Ga bers). aS
100.78
EEVCO SWCD eiecsa: ese scree Bee SAS HATIT Rewer » 22.59
Motal: Muxes eee dese duvede seuquniecesn: cdpaeaveimn pdaraxt Lees 2.44
Specific Qravlty® occicareererer aveew eer apelesaaadien «cane 2.18

THE UTILIZATION OF CLAY FOR PORTLAND
CEMENT.

Aside from being used for the manufacture of clay pro-
ducts, there remains the possibility of using some of the
Alabama clays for the manufacture of Portland cement.
The three essential elements of this material are lime,
silica and alumina. The first of these is supplied by
limestone, marl or chalk, while the other two are contain-
ed in clay. *

In the manufacture of Portland cement the two mate-
rials are ground and intimantely mixed after which they
are burned to vitrification. During the burning certain
compounds are formed, especially calcic aluminates and
silicates, whose union with water and subesquent crystal-
lization causes the cement to set. The mixture of clay
and limestone is manipulated so that in the finished
product, the per centage of lime shall be equal to 2.8
times the silica plus 1.1 times the alumina and to main-
tain this constancy requires that the composition of the
materials used must be constantly watched.

While it is possible to get a proper cement mixture
from materials showing an appreciable range in composi-
tion, at the same time care must be exercised. Highly

UTILIZATION OF CLAYS FOR PORTLAND CEMENT. 201

siliceous clays or limestones are undesirable, the materi-
als used often contain ferric oxide, magnesia or alkalies.

Their affect according to Skewberry is as follows:
Ferric oxide combines with lime at a high heat and acts
like alumina in promoting combinations of silica and
lime. For practical purposes the presence of ferric oxide
in a clay need not be considered in calculating the
amount of lime required.

Alkalies so far as indicated by the bebavior of soda,
are of no value in promoting the combination of silica
and lime, and probably play no part in the formation of
cement.

Magnesia though possessing marked hydraulic pro-
perties when igniled alone, yields no hydraulic products
when heated with clay, and probably plays no part in
the formation of: cement, and it is incapable of replacing
lime in cement mixtures.

The following analyses taken from the 1897 Mineral
Industry will give an idea of the composition of clays
used in portland cement, while following them are several
Alabama occurence that could no doubt be used in ce-
ment manufacture.

DETAILED REPORT ON ALABAMA OLAYS.

202

Ost

St'9
gig
80 GT
06°L
06°TT
0g"8

us]

OF'g 02°81. 09°F ORCL TTT eer eT Te Auvaitep, ‘anes
T0'9 Gq°8T og'gg9 Avjo ossoog ‘mnisjog
$L°9 9T9T 99°89 “Suq ‘Ava pep
99° go'et | sr'e9 "yy oon
69'6 62's | Og'ee “ATV ‘BHO OA
19°F 93°81 | 86°L9 "G'S “BoyyUe A
13's Oa ie ee Wor, ‘wostosg,
pare GE TE | Odeo ||| seen ciate © ‘psnpueg
UF
G6°0% SF '0F PeOTCTer eT eee reer es zk 'N ‘9 JOTI MA
GT'8S LZ°9g eee. eT RECER Phe x “NU ‘STL@a sueTy)
— i
O8N| ‘oo3m) OF 0080 | O ea “O “IV 7018 “ALITVOOT

SAVIO NOIAXIOL

UTILIZATION OF CLAYS FOR PORTLAND CEMENT. 203

‘Teqeaos Jo uoTyeaedo pue que

qey} UIEes P[Nos 4t ‘WINOg oY} Ul SeLTOyoR] Ate Jo souESqE OT}

WYSI[GeISS OY} 1OJ Poy JUoTIEOXE Ue s1EO eweqery

pue ‘[el1o}eM SIyy JO osn SulsveroU! OY} TM

‘OTQRTIVAR oAv YUOTIOD PUBTyI0g I0J posn

g[edoyVUA OY} GIO FVUY OS ‘AqBIG OY UIGIIA soIqT(eoO] Aueul 4B PuNoj Oq 0} ST FLVYO IO AVU PUL OUOSOUULT
‘goSed Surpooeid oy} Ul UeAIS SUIEd £O8EO [BUOT}IPpB ‘moy @ UBYY CLO @AIS 07 A1esse00T 4OU ST 4]

9F°ST “Ty “14 “4 89°L 86°8T OGK09 ieee eee op remey ‘projypog

OFeet ag ‘ay a aa are Moore, [resseceersesssesssessttnnnnasssttters TUN 8.00882q

316 “ay “4 03" cad 98°6Z 03°89 "0D HeqloN “YIM “Lf “M

09's 08°T 08" ors 00% 00°S% 08°29 ““OULN SeAvaD “Weg suru

09'8 9° 98° OF CL" 86°96 CUO: pe ee oi eylayedd

ge'h eee 98° 09° ELS 0E'1z @s's9 CERO RRR we Bw SOE esooleosn, "gs .qquo ‘H ‘H
us] AIV O03 or0 fo*eg | ‘O71V | 7018 “ALITVOOT

SAVIO VAVEV IV

Page.
| Absorption of clays.......... 39
Air. shrinkage of clays 23, 26, 28
"Alabama as a clay producing state 1
ae clave physical and chemical properties............00.....0000c08 114
BNALVSES Off vccessarsroreaneetanedsecdcceesenes ga celia tesartesintla fata 52, 201
ue “ combined water of.................. sa Barapa Sanita Mean ebesetrs 24
us “composition of... f. gseiiiaiuavataceeatnctaati 5
" ‘¢ geological relations of............... _ aight oitvercndes vain 8, 69
as MMO ISUUPS, UM secure ee suesosiacsaaited. seid miueeeqeauienn dhecenermoactareregehinetepl 23

“ce iz 3

be “6

[73 66
a “« suitable for making Portland cement...................... 202
Alabama tres lay. isicssapcase iciadenaconsneumlates aaatenda Gene nsivioairennastaiannss 131
a fire brick works.......... ie paasleabe tent me Cana RR abmaA oN tagectha encanta 109
iS Metamorphic rocks “— 70
Alum in settling of kaolin 66

Alumina determination............. +h aoe 47

<¢ in excess in clays 16
Archaean clays 70
Algonkian clays 70
Alkalies in clays 11

s& 6 (Ghinaand ball clays).......s0.cccsesnensabioessnemnenaenens 115
& «determination of. f 45
' Analyses of bauxite, Rock Run, Cherokee Co...............:s0. 148, 144, 145, 146

Analyses of clays, ultimate. ..............:ccccccecceeesceeeepeesceeenetertsitaateeees 45, 54, 57
EE AE pati onabecormoss snnemaaies sn ee as 49, 50, 57
« 4 «Alabama clays 52
7 “OG 6 « 201
Analyses of clays, Bagwell’s, W. D., Fayette Co 194
« « Beckwith’s, W. J., Colbert Co 199
‘<6 blue, from near Glen Allen 197
fs «66 prick, Argo, Jefferson CO........ccccceceeeeereeeeeeeeeeeeeee 193
“ ke “Birmingham, Jefferson Co. ..............0 193
“ see ‘¢ Woodstock, Bibb Co 191
“ Ge et ching, Anderson, F. Y., DeKalb Co...............0.... 125

“ se 6 Chalk Bluff, Mixcion C Oresscatiistinaeaessnerenne

“ oS 2 ‘* Eureka Mines, DeKalb Co

rl «Frederick Briggs, Marion Co 128
“ 6 ‘© Hughes, J. R., Gadsden.............. 120
“ be ‘¢ near Kymulga, Talladega Co....... 122
“ “6 ‘¢ Pearce’s Mill, Marion Co......... eee 129

206

CLAYS OF ALABAMA,

Page-
Analyses » clays, china, Pegram, Colbert Co.....0...000.0.ccccccsseeeeetereeee 120, 130
“ ut «Rock Run, Cherokee 00...............:005 ee 118
ee 6 EE Di: Clit GaCale®. sc cevecseromen ster temuscmveesabvevaenonncee oe 85
“fe & flint, Choctaw Co ‘ 158.
es fire, ultimate and rational............00 oases 54
i oe eS Bean, J. C., Tuscaloosa Co.............6. eects eee 154
“ = « «& Bipbville, Bibb Co 151
See ‘‘ Hull’s Station, Tuscaloosa Co................s:000 153:
aS “near Fort Payne. DeKalb Co...............00..665 150
e ses ‘© near Valley Head, DeKalb Co...................... 147, 148
thy Bes ciet ‘© Oxanna, Calhoun Co.............:06 cece 136
“ ee “ Peaceburg, Calhoun Co..............2...::0: eee 135
“«« « Pearce's Mill, Marion Co 156.
6 Gera ae “ Pegram, Colbert CO oscar casas tcncabannreqbanadeaiete 157
“ 6s ‘““ Rock Run. Cherokee Co....................+ 137, 139, 140, 141
ee ‘© Woodstock, Bibb Co 152:
te BE NE POT CIGN st goiter. Sikh us aawaei ess wleaiuieaterdiaecnewsacecoe sae ees 201
6“ Oe EE" BASS" POD tet canrua aster cioqucsnnese- cect nectarines themnenies 154, 155.
Analyses of clays, Missouri 168, 176, 177
“ AE ME mottled. da. sssiisceweedeverencad = hctisgiaadane ehaedeeteitansabiockonenen 197
“ tc Palmer, H., Marion Co........cc:ccscceeeccecceceseseenenneeee 175, 196.
“« «paving brick, Tuscaloosa Co 188
“© «© porcelain, ultimate and rational.........
nd pottery; J. C. Bean, Tuscaloosa Co...
6 ee H. H. Cribbs, Tuscaloosa Co...
“ ke “ Oribbs P.ace, Lamar Co.........
Ga ‘« W. Doty, Fayette Oo..............
fee te J ee ‘ McLean’s, Elmore Co..............
“ eo ‘Rock Run, Cherokee Co............
CES Oe 88 “Thos. Rollins, Franklin Co........
“ a ‘© Pegram, Colbert Co ss
«pressed brick, Oxford, Calhoun Co................0005
6h EE ae ba ‘« Shirley’s Mill, Fayette Co............. 190.
@ Tan-yard Spring, Lauderdale Co................ssseceee 111
sh (¢ +6 white earthen wWare.........0..cccccccceesceceeresseceeeeeteeenes 54
«white plastic, Tuscaloosa...............00000.csscseseseeees 167
c «© slip, ultimate and rational............00..00cccce cesses 54
“ eo ee Bloneware, Blount Cosco cscs vss setoaserusiatee seco 161
fo hone Chalk Bluff, Elmore Co...........0000.00 163
be beet ae ve Coosada, Elmore Co...........:1cccceeeeeees 166
“ be es Fernbank, Lamar Co................:::0:00 173
ee if Robert’s Mill, Pickens............. 171
“ H. Wiggins, Fayette Co............s..66 178
“ « “refractory pottery, Shirley’s Mill, Fayette Co....... 176
ae 8 ME | ODO sccensaseuenpeninncenwescdlaskis eonereny Gea utauneekaut ees ca teee’ 168, 171
Analyses of kaolins, rational and ultimate.................ccecccce cecceceeeens 54
fe 8G Ran Golph QO. is sesce cco vniusin daiensnceassinbhaanawensenes 71
Analyses of shales, Jefferson Co...............66 cette eta tee ee eeee 185
Analysis of ochre, Elmore Co..............:::cceeeeeseeccee ee et eeeer enna 164

Anderson, F. Y., DeKalb Co., clays Of...............::::ccececeesescseeeeceenanone 125, 149

LIVDIGA, 207

Page.
Ammonia in Clays........00 ee eccceee cevecnese senseensssesssstenseseesene seen 11
Appling’s, Sam, well, clay in...:............. Mieaseaenouser iste aarearteaiemaentets 102
Arab, Marshall Co., clay and pottery 80
Archaean and Algonkian Clays. ..........0...cccesssescccsscesecscessseeesseeensenees 70
Argo clay, Jefferson Co 193
Audtange County Cla YB csesetrisig siercecvcees wad atetcawesite 88, 89
HO VAMALYBIS Of ss cineesaesan soe vcduu tuts iantomtse ous teauuebnks 201
Auxtord fire clay, Tuscaloosa C0. ............cccceecccsssceceeesseseeeceseceeeeess 152
Bagwell, W. D., Fayette Co., clays of................00.. sii jeanirpwaicaaeataides’ 194
Ball Clays. ssc aus ke acorn eo eee w.... 115, 116, 117, 120
Barite with clays, Calhoun Co..................00...0.. 76
Barkerville, Dr Chas., quoted.........000... cc cceeseseeeees ages 45
Barnes, Edmund, Lamar Co., clay 101
Bauxite Bal yG66)..3ccg:escseasasintteouss aeirencatan suceroeweaveunguatusiteertecuuiey 1438, 144, 145, 146
Bauxite banks, clay in...............::::cssueeeeeeeeeee 76, 136, 137, 138, 139, 140, 141
Bauxite int Cla yess: ssuisevuesesienctuacesnsnas cc. ash eseev souk fevanterais dotesaacmeeley 4
Bauxite, refractory......... peje ved wekaeaMWdesaapintdesevscwabaiad siniese nav bdeaesiNeniauadees 142
SU XILIG CLA YB siie ccc cce cn thSseetcson cesstinr nin lecalicas shieohaenevenees ceseeeists widehas aed 139, 141
Bean’s J. ©., clay, Tuscaloosa Co0............ cic ceeceeeeeseceeceeccesereneeerenees 27, 28, 97
a 6 fire clay, Tuscaloosa C0.......... cece ceieeeceeeeeaeaeeeees 153
‘6 pottery clay, ‘ BO SeaevhiS Salamanca esas b dnmataposehoutansin’ 169
es “stoneware clay, Tuscaloosa Oo................006 169
Beckwith; W. J., Lauderdale Co. Sad of. 111, 198
woe analyses of clay of... 201
Bedford élay, Lamar Co., analyses of... i ediatinge aaareccrapeeveumcaty 201
Bedford, Lamar Co,, potteries NEA ss ee viesurinic 98, 172
Belgreen and Burleson, clays between ‘108
Bessemer fire brick works..................:..:::0::08 sagas exe aniesseeneawees 92, 150
Bexar, Marion Co., clays near...........:.cccc eects tess eeeeeenees 106, 107, 194, 196
Bibb County clayS..............:ccccccseeeceeecetetteee tereeeeneeenenes 75, 90, 150, 151, 191
Bibbsville, Bibb Co., clay at.........cccccccecceee terete reeens 91, 92, 133, 134, 150
Big Sandy Creek, Tuscaloosa Co., clay OM.......-...0 eccrine te 94, 95
Binding power of clays, see tensile strength................eceee eens
Biolite in clays 43
Birmingham clay 192
“ shales 184, 201
Bishop, quoted. .............cccseeeeecsscse etter eerie cere etnee eb eer eneep tenes rnnees 31
Bitter taste of clays ire 21
Black, J W., Fayette Co., quoted............seee ccs eeteeterieereen 103
Black cores in Dricks............0c0ccccceeeeeeeesseeeeeceeseeeeeeeseeneeeeeeeseeaseaee ees 15
Bleaching of claya...............:+00 -_ 17
Blistering of clay ware aos 15
Blount County clays..........0..... cceeececeeeeseesaeeeeeeenaannaaneeeesceeees 74, 160
Blue clay, Marion C@............ccccccceeee cent cient tree r reer eteeteieees 197
Bluff and Brush creeks, Lauderdale Co., clay between....................5 111
Bogg’s pottery, Elmon Co... 0... cect eeeeerceeeeeees 88
Bohemian kaolin. analysis of.......000..0..ceeeeeeeeeeeeeeeees : 54
Bone china of England a 18
Borings, Clay i... eee eee 99, 103

Box spring, Tuscaloosa Co., clay of

208 CLAYS OF ALABAMA,

Page.
Brainard, A. F., quoted..............cc ce ceesseteeeeccccceesescsenseesueccssueeeeeeees 123
Brick Clay8........ccccccsees pee never ree 72, 73, 76, 88, 92, 97, 181, 190, 191, 192, 193
Es? LOANS 3.32 jiu sete Tabi du the laude des co noaauedseddaeawnedinnataceanamachduitine’te 112
“ 90, 109, 150
68 SBIOS scsainaiinraca cteieiaaeaactianen mmneatenpnnaneacns : 184, 185
Bricks in U. S. in 1897, valuation of............... 1
BS * MULTI O G sacistonaesiisicaindst Sqmbaag: daatitens cies! sa hav aianee aa celts dstlseanednenay ayness ees 80
Brown, Wm., Lamar Co., clay of. 101
Brush and Bluff creeks, Lauderdale Co., clay between.................... 111
DUEL, WATE. 5. Gssiessdaer now elevecetsacunaheiine sus siecomalade Radcuucinudinebatogsdesnuaiautias nents 18
Buh stone Mint: Clays cist cowspedoses epssewswsnodevevsemnaysiampesreeerwiesiocewe veers 112, 158
Building brick clays 72, 78
fe “ loam...... reer 112
Burned clays (Q70g)).........ccccccccccecescscecessareeensseseeees 27, 182
Burleson, Franklin Co., clays mear..............0....ccceecee case cesseeeeee enn eeenes 108
Caleareous clays 17, 183
Cal CIO i scnsanecasese sdeinnreecuedecantisient patie 16, 42
Calcium oxide determination 47
Caldwell; Di. 5, QU Obed icc. cisevccniaraxecdsapeceiataniudtessluagaasstine Soave waganedcaneactes 72
Calhoun QGUrty: Cla VS rieptencesscvantdovssbarenseroreane Bes
“ kaolin

Gam brian Clays viii stercuses vs sisrwatsiee sisal nakcawanneanadocoessinvadanesens
Carbonate of lime in clays....
Caraonate of iron in clays........... 44
Carboniferous plastic fire clays... 181
Centerville, clays near................. gniviodiietoes Se unos siauneaeaeed qm etnewarn 90, 91
QUAN Koi set naaesecnisdes desman alse viorsonen sn sang Wagaate tense cenmeatenieen aeenaens deg suites 78, 85, 201
Chalk Bluff, Elmore County, fs 88, 89, 162, 184, 190
ee ES Marion: Cy semsssiseaiinens Saeageonavtabeneuetseaieds 6, 25, 26, 52, 106, 117, 127
Charleston limonite bank, ‘‘clay horse” in ........0....00...cccccccceel eee ee 75
Chaney’s pottery, Franklin Co..........cceccceccccec ccs tc eeeccceeesecuaveaaeas 108
Chemical and physical properties of clays 114
QW GSMIGAD CLA V2: casices canis a csicra cts cei aaanioee sas ea inca oma canaeceaueantetigs 58, 69
“effect of heating Clays....0..cccccecccccecccccccesea cesecscessenanens 38
fs properties Of ClAYS...............ceec cece ccccsceeceeeeteaseseasceaveeensesnns 9
Chemically combined water of clays a 22, 24
Cherokee County bauxites.......0.... ee ccccceccceeeeeeeeeanee Sas cinugincains 142
ee «clays 76, 118, 136, 161
Chert for glazing..............0....0004 79
ae County clays... 72
“mica ‘schists .. sitaned echt eases 70
China ware clayS..................s6008 ....79, 110, 115, 116, 118
a OE) SRGOMIICG id setae ana sthowndeintysasednsad chsamstinennaaaimons acne rere 71
Choctaw County clays 26, 112, 181, 134, 158
Claiborne formation flint Clays..............ccccccccccecceeeeeeeeseeeteeeceuaeesuseees 112
Clarke County flint clays
Classifica tionOF ClA YS...) .sc0scerpessecuzscugeaeomaiareen ciaveoenispaseysnamaeus cedaut
Clay...... sgealpeaaamdingie pun ah slealnuanlijea sue seaetaseu aah epiesamedenaueaveagectensnagansedirsieocs 3

Clay, chemical wsssoswenssinscenssionasseennoens snanse aeons: Sea rsumeoaneanecoaee weatea et, 58, 69

Page.
Clay County clays oo... ccc ccc ceccccccccsccceccessesssecucsvscevtscueuscersecaseas 72
#8 ‘* Kaolinite veins... ; 72
6 *¢ mica schists............ re 70
ae ‘¢ mica veins...... ...... 72
ee «pegmatite veins 72
“Olay NOrses "ieee as iseiece nied aslngeteid asa haan desseanaainttate. gigeeentays 74, 75, 76, 108
CL ay” OPUS TN ees cas ict tas Sheutatiel tesyaantl dals ¢tcalyiite soak ualireanh de date tsause, 3
Clay produced in U. 8. in 1897, valuation of. 1
Clay properties..............sssssecceessssscssceses cesceeensesecennas 1, 3, 8, 114
Clay prospecting..................0.. Bune 59
Clay rocks (shales) naaea 7
Olay SUDStAN CE ?? i. sean aneatauerieancneeekt dhmus cuaueesetie casmihonsuadebeacsacecnves vit 9, 50
57
: 9
FE GistribWhlon | OF i iice cacctoescsmsesensstnadaiamnosanananigelnaatvexergesacus csc 8
« mining of............ 59, 60
« miscellaneous 193

EE“ PPEPATALON OL: (005. s6. 02. ccnsesvacind ew eavaccenseiseowayeekca naa seedesedensaniedoncts

sé

for headstones of graves
‘© for Portland cement

‘© for vitrified bricks........
“for whitewash...............
Clays from feldspar rocks.......
oe 66 PNOIBSER : 4.55 .dencsaveeurierscedcreadednens
sé 8 BLAMES: csisicaivncnsasd cceeaceieasas scone usin
a £2. SMCS POLG) si isne daveas oo oiireen dca iivadewecstee ee
s ‘« Paleozoic shales
Clays, geological structure and distribution of...........0.0.... 0. cceee cee 6
‘* in sink holes, ponds, etc 73
BSS © TINEV OLS ss aceciies afe saute annie sec asst salen con dcaa ae aaanimandcmmenamenieaue nae: 70
Clays of Alabama, geological relations Of.............:cc00:cceee sexnaeies ‘ 69
‘¢ “ Mississippi sauvegeivelves 83
* © Red Mountain, Wills’ Valley............ (Saga lad acne one neavan sabaeeeces 77, 78, 78
Olays, residual.............. .ocesseseeeesteeeeerceeecnee secs etaeeneeeneaeonneeeseeeeeeeacas 5, 6
“sedimentary 5, 7
Cleburne County kaolinite veins..................:ccccsececeees 72
sf $6 “MICA VOINS...4:...5sssenscderesccnnseeieseesice 72
HH §€ MICA SCDIS(S. «0.605 ccssessseensreonaraaaieenanses eeadeqwnggeiae 70
ee ‘6 pegmatic veins 72
Clingscale’s, Dr., Miss., ClUYS.........-ceeeee cnet terete 85, 112
Coaldale, Jefferson Co., paving and vitrifled bricks 80, 185
“6 a ‘¢ shales 184
Coal Measures, clays from..................08 80, 131
Coastal Plain Report, quoted 82, 88, 91, 94, 106
Cobalt in: Clays) iss siisiscscposguuisssavansasenedesunnestonseiemadsisysie aan gesace devsrasets san attee 116
Colbert County clays . 82, 109, 129, 157, 180, 198, 202
Color bUFDIN EG CLAYS: wscs:i02, ssoncaareenos ea anwvecunretauaee cata mee nee theanaesavesaniet 58
Coloring of clays by iron 13
Color of clays....,.............. faa sey 15, 39
Combined waters ccc sicssasisiscisiascsedect vsisnnesonesesseddeaay snceiacedsuenes ovedioos 28, 45

210 CLAYS OF ALABAMA,

Page.
Common brick ClayB............cccccecccecscsesessecccccscccsteceeeeseccsasaesanececceaes 181
. “in the U. S in 1897, valuation of 1
Composition of clays, see amalysis.................cccceccceecccesscuesceceseueccaues
Concord Church, Fayette Co., clay near......... 103
Conecuh County flint clays............... ci ccceeecesesteceeeaseeseeeeseeeneeeeree 12, 131, 158
Cones, Seger and Crame?...............:00:::cseeeeee 32
Coosa County Clays. ......ccccee cee cceeeceoeeeenes 72
t BAO © | AMIGA SON ISU 6,5 15.5 pc5 co scend sence csanaelavduergnesniaaeneeeabesievancneats 70
88, 165
Coos. Valley Region, fire clay Of,.................ccccceceeeecceeeseseaeeveeteeeeonee 133
OOOK; Quoted sic oietctecnieise sieteasied aussngedslteengiewaereacienevneawes 25
Cottondale, Tuscaloosa Co., clays near 93, 94
Cowles’ Station, clays at......0.... cece eeeeee anes oe 88
Cracking’ OF: ClAY Bis: cicinevcuictos dens iivsition saiseua sseauaciene dededebeenedaaasecndere cn eaeven 27, 132
Cramer pyramids (CONES)... ie cc eee teen eee aseeeeeeeenanaenees 82
Crawford, Russell Co., clays
Oreta, COUS CLAYS) sis ccese- cecwiie gia gaissanytsoniatneneeatmeseosennens
Cribbs, Colored, Capt., quoted...........0.0. 00. eeeececceeseeeereeeeeeeneneens 98
Cribbs, Dan., pioneer in making Alabama clay ware......................65 92
Sete: Fleming W. Lamar Co., Clay................cccccscceuseceeeseneceeeeessees 100
ee se ee 66 POTOLY... ee eceteeesessteterstesteeerees 92, 100
Cribbs , H. H., Tuscaloosa Co., clay....... [ecwbldacdaheacaudnaavesuantoeys ees 92, 93, 166,202
Be Ee a FES BOUHY sc: sessed seid Aeiecaasensdndveaaiie 92, 93

Cribbs, Peter, Lamar Co., potteries.........00.ccccccecsccssccsesecsesseceeares 92, 98, 99
Cribbs’. Place, Lamar Co., clay Off.............ccccccceeeecteeeeeceeeeesaeesesneneee 172
Crystalline rocks in Alabama...... hater cena Masia giclee atdaies Qeaantegaiotatee 70
Davenport, C. C., Cherokee County., clay from................ceeeeeees 161
Davidson Bros. Ppottery............ccccccescccccseessccsseeecenne coaseecaeeeeceanerseees 101
Davidson’s Store, clay at ........ ee ccee ceeseeeseee eeeneeee seseeesseas 107
DeArmanville, Calhoun Co., clays Of..............cc:ccecceccceaeeceeeeccueeeeeene 76
Denman, Jas. Cleburne Co., Clays Of...........cccccccseecccceeceeeceeceueeceuees 72
Dekalb County clays............ccccsecsseeeees 77, 78, 79, 123, 123, 146, 148, 149
Detroit P. O., potteries Near. ........ ees eccsseccecetssececeeeeereuseeerceeseeacs 101
Distribution of clayS..................:ccccceeeeseeee oe ihn dadanhtand seamnareeinlone’e ai 6, 8
Dixie Tile and Pottery Co.,Oxford, clay of...... 76, 184, 188
DGVOMIIGG tes ssccactascasion assess sae sects veuieges dee Hawa ge daemameceaeipesamemseenaseabeineinsie 44
Dolomite in clayS................::cecssseeeceee yee sae cosh eanmu eel onceneneeE eat wees 16, 19, 44
Doty’s, W., Fayette Co., clay
Drain’ pipe: Clays ws.ccsseecssseanccsecsavesetwesvea svevsvsidicacseeen acne sncnveeweanaees
Drain tile in U. S. in 1897, valuation Of...............ccsesecccuencceseecceccuesers 1
Drying of washed kaolin......... 0.00.0... on weg eeteteass 67
Dry process of moulding bricks 183
Dyke’s bauxite bank, Cherokee Co. , clays OF vs sesieezess 136, 137, 138.189, 140, 141
Dykes limonite bank, Cherokee Co., clays of.. 76, 118, 136, 137, 188, 139, 140, 141
Earthenware: Clay cisccswoscuresavessiossesasteacdstecaveredvaaiantdecssseies 122
Eastport, Colbert Co., fine silica white at 112
Edgewood, Elmore Co., ClAYS NCAL........ cece ceeeeseneceteeneees 88, 163
fs *8 OCDVONGAM scicscsoierssicdessviesnnaween naveetes 164
Efflorescence on clay wares 17
Eldridge, clay near...........c. cs eceesasssseeeseee cereseseceeee eee ie s¥ars gh osag dueeenice 104

INDEX, 211

Elgin property, Bibb Co., clays (1) a ORO A AP Va sas rh
Elmore County clays - 88, 162, 163, 165, 190°
England bone china... ccccecescscscaccsessecseeecerececeececeesceccen 18
English and Mining Journal, quoted..........0ccccccccessessesesscsecee even 31
Epsom salts in clays... ccccscccssesesee seceeee, 20
Eureka Clay Mines, Dekalb Co.,........000. ccccccccssceees noche soariines 122
European clays, silicia im... ccccccceecees 20
Bate CGY 8 svccsaceo signa ceoantire esonccducaaaveiy aicteyeoderoes 23, 25, 133
Farrell’s Mill, Macon Co . dave near. 88
Fayette County ClayS...... eee 82, 96, 101, 102, 103, 174, 175, 176, 178, 189, 194
Fayette C. H., clays at and near 25, 102, 103
Welds par. 23 acid ccaseseicivesderttecscsaccinscterses eavaawlecitia cx clscateein aeons ~ 70
Feldspar clays................. cits sass : 12

BE ATU CIES poco aie sitaaernettn itt a he nd celcetge antenatal tn 16, 18. 28

ee SS TAOMN vi swsvos auiied savin biases xcoasistingaidcs
Feldspar of granite veins......
Feldspar veins, clays from.......
Feldspathic detritus...................
Fernbank clays, Lamar Co.,.......

as Pottery 88 ck 1, a sewtsnecaaSeecsnassmatiadh pe yan aaleenlomeuetaeaeedenes hie
Merri: Salte:in: Clays ssis.ctoventcasenanussanianydvaceusoruecaguedavgad waisueesiens teaode
Ferrous oxide determination. ......0....ccccecececcccseccccccesssensevecsenaanseeeeens

BE “BAUS AW CLAYS sce wesveunsiisvd cuvammnuandes Gi neirebmedbnmenienean leet ata Sa 14, 40
Fire DriCK si.4scscccaseossceetswss van 86, 87, 94, 132, 133

te os 78, 79, 80, 86;-91, 117
“ * manufacture .......00.2 0 eee Eesha sunsiesiashamneisgeselyant obs Megraer 92, 109, 150

Fire brick in U. S. in 1897, valuation OP essai ahha ghemasceactasantonte “1
Fre: ClA YS, ciehcisincssnciwernntavaerinsssdecennnes 92, 94, 97, 105, 110, 112, 130, 131, 182, 133
Fire shrinkage in clays 26, 27, 28 -
Pin ocsscscacaiacsoaestenaseness 41, 42
Flint clays...... sie zai ae 3, 112. 130, 131, 158
Florida clays Lg 6,
Flower vases, manufacture Of.............ccccsseccseeee oe ceeneeeteeeseegereneeceens 93
PUM ROS IN: CLAYS ec cesnenisswersaesearuerrenguasevesqsaiiewebeasqnadeceae waaay uenealcimedaet 10 ,29
Foreign clays for Portland cement. ; i 201
Fort Payne, Dekalb Co., clays near..............000:00 schiticeswaeteeavrsraas 80, 149
Fort: Decatur, clays at 1d vic. ccccsssa.cesutsoetieaiiattiienee cacnncseatereasenneseeee’ 88
France, kaolin from...............0...0 Sdiancuieibouieeeesavee 54
Frankfort, Colbert Co., clays near 110
Franklin (Ohio) Company mines, Dekalb Co.............cccchicseeeeeeeceeeeees 78
Franklin County clays.............cccsssseseceseeensceres a sssseee 82, 107, 180
‘Friedrick, Briggs, Marion Co., clays of..... : sey wi «» 106, 127
Free silica in Clays.........0.. cc cesseeeeee eee eea eee seeiweniese 20
Friendship Church, Lamar Co., clays mear......... 0. .cc.ceccsssceecceneeeeree ; 99
Front brick clays............ 182
Fu- ibility in clays 29, 31
Fusing point of Seger cones 33
Fusion of clays.............00. POCO SESESCE ESO OSEOOEEESEOOOESEOSS 38
Gadsden, Clay MEAr.............:scssseensrnsenereessoeeceesseesseneestsssanees sieeuess 74, 117, 119
Galtman, Marion Co., clays mear.................c cecssssecssesecesecccsscensescess 101

212 CLAYS OF ALABAMA,

Page-
Garnet in (Clay Sig esivesescieansvinsdetine stevens veceshen fj seend eunnieebacerenaectomet cages 14
Gassett, M. E. Marion Oo., clays Of..... ...seccccceeeeeeseeeeee 106-
General discussion of clays ..... ............ 3
Geological relations of clays 69-
Geological structure and distribution of aos 6
Geological Survey of U.8., quoted 58
Germany Claye.................2.:ccccescsseeneeseenees ledeness 54
a AG OUD cavicvananectusuaviencseontuxienasinn: aetindesenidoaszsnaadededsawensainnnsunelas 55, 56
Gilley’s branch, Franklin Co., clays Off..........ccccccseseseccseeeeeeeeeeeseeees 108
Girard, Russell Co., clays Me@ar...............cccccsececeeteeteceeseseeeereeeeeesanenes 87, 88.
Gaza ng CA is csi wicc sande inideiada sander ieaieedoaeseiaeadencnegstaseuedssoussSésseasatenss 162
Glass-pot Clay. cscs cscvsneirissiedssesrempiocesanieetines bans oyabhcaamna see coapencuncneen eas 97, 154.
Glen Allen, Marion Co., clays near
Granite veins in Alabama...............ccecccccccceeeeccenecsesaueeesaeneeseneeeeeees
He $6 5 Clays fr OMilwciysic toe eeriaide cid sayin ssiealettie Selec se aadesaeved eee eaee’s
Graphic granites (pegmatites)... post ccusleumeebanevausavneees
Graves, W. H., Birmingnam, shales Es dent ahis'dlvetsacteilsinit Seeiaiatecnaeeetts 80, 184.
Green’s, J. B., ‘Lamor Co., clay 173
ot 6k 6c & Ob 98
: 100
123
...27, 182, 183, 158.
vie sek det veacea annals eabac Sidecar escent! 101, 104, 105.

CRY PSU IN se cecchs ds aectneastalpcaecte oh dacetananea eis ease hates amie de ae asthe neocadnagadamsieeds

Halloysite.
Hamilton, Marion Co., clays near

Hickory tree limonite bank, Cherokee Co., clay in..... 76
Hilgard, Dr. Eugene W., quoted 83
Hopkins, T. C., quoted 155
Hornbiende in clays ............. or 14, 19
“Horses,” Clay.......ccescecee eee antiwradsny dieresiees 74, 75, 76
Hotop, E., quoted 64
Hughes, J. R., Gadsden, clay of 119
Hull's Station, Tuscaloosa Co., clay Mear.................cceceeeeeeeeeeees +..94, 133, 159
Hungarian porcelain, lime in......:...........ccsseesssseeeecessneeseeeeeeecaaeeeeeee 18:
Hydraulic mining of kaolin.......0.00..0... 0c ccsseeeseeeeseeecceeececeeceeeetesseeeeens : 62
Hygroscopic water (moisture) in ClayB.....0........cc ce eceeeee ee ceeceeens 22.
Igneous rocks in Alabama 70:
Impervious clays.................. dega ailpnaudedissbedwenseses 30
Impurities in kaolin 9
Incipient fusion of Clays... 2.0.0... eee eeceetee eee eeeceeeeeeeescsen sgh enitatie 29:
Insoluble alkaline compounds in clays..............:..c.ccsssceneee eee e neces 12
Insoluble residue determination in clays... ceeeeeeeeens 48
TPO 10 CLAY Bea sssissses aise cpsetearreamceasennsenitenvanceveed 12, 13, 14, 43, 47, 51, 115, 116, 159:
Iron in beds with clays, purifiication of 74.
Jacksonville, Calhoun Co., kaolin from 74.
Jefferson County Clays............ccccceececeeeeeeeeeee es 192, 193

ne ‘¢ shale for brick and cement manufacture......... Sake 186, 202:

John’s Mill, Tuscaloosa Co., clay ate..........:ccesceesscee ceeesseceeeeteeeeaete 96

Page.

Jones, Lewis J., clay in well of....0.0..0occccccccscccsececscsscssesceseesurseaecsees 99
Jugs, manufacture Of cece cccccevscsssussusececcecuaveseseececvevaeee 93
Jugtown, St Clair Co., pottery and clay at..cc.ccceeeceseesseseeeeeese: 83
BOM M sssseronseonns oervciveasinasnaseasinivecesesniiae »..8, 5, 9, 41, 55, 56, 82 86, 106, 115, 116
; 03s 8 1 ae eee eshivakiaseaulnsigatias 67

Bee, AMM PUTTGI OB sc aevelts let dent ss as auvea te taacigad tiszebicn soi intestate 9
Kaolinite siaheidise Sclipbinamiewe Wataschang 3, 4, 9, 10, 40, 69, 70, 71, 123
ss COMPOSI OMe esis! deiicscnsdriauiaoctnedeatinase naainelvbannwaninioteeeieadeeeeimitiiene 4, 10

He from granite viens 71

" in clays 40

a OB BIN ceca vanecnanesgneaataces iamuanonveeiecs 3

se V GLI sesciceateeccstiarcne saaeita ak ueieutat Sta acanaiah wm ouaeten 72
Kaolin mining... 000... ates 61
Be: AT OSBEB: Loi iaias'des. eeamanusen negates 67

‘¢ residual beds 74

SE ~ SVAN BS dauchmrritin is, 7, 61

‘¢ washining 62
Kilgore’s Mill, Dr., Franklin Co., clay near 108
Kymulga, Talladega Co., clays near.......00..00.cccccccee be aeeseeececseeeens 74, 117, 121
Lafayette formation in Lamar Co ..............ccsseseccceccee ee ctesensseeees 98
Lamar County ClayS............ccc00.c000cccccccececcceceueetaueeaee sesceecsuceeees 98, 172, 173, 202
Lapsley, Judge J. W.. (Vineton), Autauga Co., clays near........... “a 80, 90
Landerdale County clays ........0.00..ceeeceseee ee eee eceeneeneeeeeeeeteseseeen “111
Deachin p OF Clays seissticnssgies Sar shia sntanes semeawccclnatagsbatacwonaecasyiawe dentine Mes 74
TiOAM CLAY sdisesvceua anes meven wstesla eredan diet ssciaya swinigalbaibbi de vives aideuies sonsnuatiutseamidatsdind 23 25
LeChatelier’s thermo-electric pyrometer 31
DCO! TN CLAYS sia a5 cies wis di dawivstnasaas aradasneccaeweaenamnites saeosuncmuuiud ete cea wantan 22
Lilly white, clay used for......0........ccccceecccseeeeeseceeneeeeeeteeeesenen ees eeeees 85
Lime determination........... sa) 47
TAM 1D CYB ss: sesccssncwssccseseeved dvecwceveanwerves ..16, 29, 51 159, 160
“¢ carbonate iu clays ................c eee 17

‘* silicate in clays 5 17
TAMER SON Cites sels sense den icblenansd temaeka ean seh curd juices auie sae daae eRe, eatin eit 201
id , clays from ; 78, 75
Limonite banks with ‘‘clay horses’..................cesseeeeeeseseeeeseeeeeteeeeees 74, 75, 76
TAMMY CLAYS isisans doericnssaucjamancasied qettueacenane vamamaete dem enveweis ee inntnwidoe 18
Lindsay; JOC. , Quoted si cccsscccecscscuegecuasing gowsnet “aor Ho vaciimanmasinnmentetiaaeaiees 102

Little, Dr. G., quoted... 82, 83, 93, 96, 97, 98, 102, 104, 105, 106, 107, 108, 109, 111
Lloyd’s potteries, Marion Co 92, 101, 107

Limoniteisvcisies seducesceuinvestoes 44
“Loess C)ays, Silica in ....... 0. eee cc ccceeeee ese eeensee ease eeeeees 20
Loss in weight of clays after shrinkage has ceased.......... 27
Louina, Randolph Co., kKaolinlte...........cccccseeeeeeec tee c cece eeeee teen eeeen ees 71
Macon County clays.............cccseeececseececcecc cece ce eteeeeeeeeeeeeeecnanentesectires 87
Magnesia determination,................ccccecccccssceccecseeesecssssasesessanececeunens 46, 47

se DTD CL YS sessed ain aceite Woeiseae aka becte rai daersine sha tsoaing deetyshenidel iecmen 19
Mallett, Dr. J. W., quoted...... ... enedeema 71
Manufacture of fire brick............. susihiers 92
Mapleville, Bibb Co., clays near 90

Marion Co. clays, 82, 104, 126, 127, 128, 155, 156, 179, 186, 194, 195, 196, 197, 202

214 CLAYS OF ALABAMA.

Marion County shale

Marly Clay 8 visncinucunssien cviwcya hints dodetanenncnovecdpapanethcmeimecaimanter edennenente
Marvyn, Russell Co., clays near
MeCalley,: Henry:, Quoted. ...0css ssc ssnecesisceveinrascatmorienneaaneinauiesieanweratin
McDougalas’ Mill, Miss., clay near..................

McLean’s, Elmore Co., clays and pottery
Metamorphic rocks...............:::esseeceeeceeeeneeeees

Metamorphism

Method of Clay Ana] VSE8; 2 .cccscige socngade doce rnyseviscenecasnocwenenbetonainnnieneeene

MICA caresses: sayiancinediedioons oa astaneadeenidoiiniauiudesniesiindadeatesies sbameasieddoustinaaneeutinies 43, 70
“in clays 12, 14, 25, 29, 43, 53
© SCS tS rssessssvervadsciveeeorseverdes seas Coveveus’ aoe.a.cavbeveseneves aesertneeaenio 70

© ON OMS! cc nisuniaine cuacted hanadaecelsanemnngee sade seeeeeee ce eeeeree eee eeteteeeeterers 72
Micaville, Randolph Co., clays D@ar............cccccccceccececceeeceeeeessnaeeenees 72
Milldale, potteries near 101
MANO BUCA sisesce gather 22sec dan cag eam uaatctmep snares Gedenanepusgraceste.ie sunimsineten 98
Milner, Randolph Co., clays near...........c:cceesesscseeeeee eeeesseceseeseeeens 72
Mine, ochre, Elmore Co............ ces death greiae buhdon'sdwmeby voevnboaemRseaeeS 88.
Mineral Industry, quoted...............::ceeeeeecceeeceee ceeceeceeteteeteeeteeeeseenena 201
Mineralogy of Clays.............csceecccccseecenceceeeeeeeeeneeeeeeseseneens 40
Mineral Paint and Tripoli Co., Florence...............:00::csssseeeeeeeeeees 112.
MELE 68 206k Yo ceded eto a eau AOE sie 78, 79, 116, 146
Mining of clays 59, 60

& * Kaolin 61
MisGellanéous Cla yale wcwisercessewvsesseeucieysseauomiciees deen ome seme aaoentade 193.
Mississi ppl Clay. sc..icciccrsceatncrcadnceaacanscededadesessdoduwauecadasteetauseddedenseas 83
Mitchell’s, J. J., Marion ©o., Clay......-.cccccccccccscecesseesseeceeseeecesstsseees 106, 126
Missouri Clay Se vicics2s.accsieaunnsmeesiies sanaedtcreeiasveseundsasvadieonaanventies 20, 52, 131, 155, 168.

88° AinG Cla Ys, SLIGA Ties, cassoacdscteveepaai agen dsaunlerlonasmansnenenaceeuase 20.
aa, Geological Survey, quoted.............00006 1, 155, 168, 175, 177, 179, 181
Moisture determination 45
22, 45.

182:

105

Monroe County clays..............s:cececeeeeeees 131, 158
Montague Clay Mines,, DeKalb Co........0....00c0cccccecceescceneeteveseeeeenee 79, 133, 146
Mottled clay, Bexar, Marion ©o........0....000c:ccccccceecess ceeesstessseeeeessseees 196.
MusGavitee inn: clays ses ssessecmminsnecersnutectnedtivas wcncchnteuatiacdet’ peeiiagaanannarsees 43
Natural glaze Clay.........0.cccccceesecceseeeeteeeeneecenee icaugungamk aasanncenion aes 162
Nelson's, Mrs. Susan, Marion Co., clay 106, 127
ING wi dersey Cla 96 shi sina canes se cnacidslosey mutsec dc aes Mosca ceadavaush vSaselsicaunes 20, 78, 131
NiGh ols; As. “Weg CLAY vss: c8, sxcine sectuszed oadsausl sncdntseveneubouna sanders sianvasiasesed 98
Non-volatile and non-fluxing constitutuents of clays... 10
North Carolina Clay 6 scayvssscacdeoceteeiattioey se sve vouaeceescerayeeaaneenes Inrenuasioee 20

ne aS Geological Survey, quoted ............::00:sc cee cees 45. 62

i * FEA OE ices basic onieicciexer sndecosayesutelsi siada bed mmniiaunilan wa tiine batahisainaie’ 54

a ME AI ss ccaeniatenatan deverearons ndaascdonasanabalbanationw se’ 61
Ochre: ed: Chalk) dss sees cdaesecyeneedigud yee seein vie actin denetienanocteandeacumnaten 108, 164

te ming, Him ore Oo: savienuriievsaigeneroucesaeines cnetasi waver dhratheneeeeaninrs 188.

ANDDA 215

Odor:Of clay ii inss5.s guise pecsaiibevsevaceevuereesGeatekveasaeteustal danati@icaennacae 11
Ohio clays

Ts 3
Origin of clay 3
Ornamintal bricks in U. 8. in 1897, valuation of... a3 1
Oxanna, Calhoun Co., Clays..........c..cccecccscseeseeeeecceccstecsseestecessecuts 74, 133, 135
Oxford, Calhoun Co., clays Gcainadieledaiigal qediwe testa asic heamiumaarnooseatieaneaneansneas 76, 188
Paint clay, Landerdale Co.... 112
Paleozoic clays...............::cccceees Pisa 6, 160
Palmer's, H., Marion Co., Clays........ccc000ccccccccsececensecssecesacsecevevees 107, 194, 195
Pannel’s place, Miss., clay O1.................ccccceccccececccccceeeree saute sesaesees 84
Paving brick clays 137, 183

. ‘* shales 185
Peaceburg, Calhoun Co., clay from.......0........cccceeeeccssse veseeeneecerseeees 74, 133, 134
Pearce’s Mill, Marion Co., clays.......... 105, 107, 128, 133, 134, 155, 156
Pearce’s Mills, Marion Co., shale 81, 105, 117, 184, 186, 201
Peden, Aleck, Miss., Clay OF...........0...cccccccce gece esetectecsesseeteteeeeeeseseaea 84

Pegmatites (graphic granites) .....0.0.... cece cee cceeenneeeeeseeteeeeetes 70, 72

Pegram, Colbert Co., c'ays near....... ...40, 109. 110, 117, 129, 134, 157, 180
Pennsylvania glass pot Clay. .....0.0..0. ccc ceeee cess tneeeteeeteseeeeseenees 155
PAUWIPS, Wie Bi, Quoted ssccssececaemcdennancoiinmscinaweaneaceeis mmgaieneaemnnienses 106, 127, 167
Phoenix City, Russell Co., clay near...............cee eee cereeeecsettenene ee : 87
Pholerite 4
Physicial properties of clays sale onder. daeidarhnjomasawieaniont iedasigtedyanaetaleacatesel 24, 114
Pickel) Dis; Quobtedss ys :scsvstewwsesenasievedai end aiaeds snileaesseanecedeuseeedanaeumsdel
Pickens County clays
Pikeville, Marion Co., clays near...... 2.0.0 ..ccccceeeeeeseeeseeeeneeeeteetiseesens 106
Pinetucky, Randolph Co., Clay.............cccceeeeseeeee ee ceeeeeeseeeesaeeeetenees 72
Pipe clays 85, 88
Pipe, sewer, in U. S. in 1897, valuation of 1
Plastic: Clays sscce seieezes yedetaessnstiien wedieasrastaled, anna 73, 76, 180, 131, 138
Plastic ball clays of Florida 6
DI AGbi CUD is icc scsislsis Se sancti ee nag ae toes tealiortesep ete ear es 4
Plasticity in clays : 23, 24, 25
a BE TER OMIN cae caunanna convicts nadeascuivanhiensd Hann vareei eae sneer 116
Plisto@en Gi Cla VS si oeceasecctiniavnveade anode cmsdaseceaneadons eeebwen ache aameaReads weap 112
Pond Clays eaiciiina cdacedasimaumancannanenteauhonenon ee 73

Porcelain clays
Porcelain earth
Porcelain ware from Alabama
Potash determination. ..................:cccccneeceeeeceereceee
O68 SUM CLAYS seaueeeness caw bettie aeansinenasaaneikeuem saves
Portland cement, clays for
“ Of “sg Mat Oriel: LOV jy cases saicensnarrancngcacence dadesroeieeas ssasistuts 199, 201, 202
POtbeOries jsicasewnsiaswdassadicesiesreve c-aaaenvad degen 80, 88, 92, 93, 98, 99, 100, 101, 107, 108

216 CLAYS OF ALABAMA.

, Page-

Pottery clay....73, 78 80, 93, 97, 129, 129, 159, 163, 165, 166, 169, 172, 174, 175, 176
179, 180

Pottery ware in U. S. in 1897, valuation Of...... 000.000: ceecteeteeeees euieeie: |
Pottery ware from Alabama...............0.. poked ceseade aes 72
Post Tertiary loams for building bricks. ................ 112
Powell's, Reuben, clay 99
Porosity Of ClAY-ccs.. siesacenardsaesdoreeoes dewes dnavammeaandsausicrotamevewsasamoednncen 39
Prattville clays................ 25, 28, 201
Preparation of clay8.................:0e Sexigehsiibaaiees apdtcawaruaersOon ds cctihaids 59
Pressed brick, clays for...............:ccccccceeeneeeceeeeeee ersten etre renee 88, 177, 182 188, 189
Pressed brick, shale for.....................005 gangs 187
PYESIE. DICKS «...05<02502 sesijnee csasen du csineasainasenss ame ves 86
a ‘in U. 8. in 1897, valuation of... : 1
Presses for washed kaolin..............cccececcceecc ee eee cece ee eee caer ete eeeneneeenes 67
Pressley’s pottery, Elmore Co.................cccc cece cette ee eeee cette net e eet eeetaee 88
Preston's, W. D., pottery, Autauga Co.............-: eee es 92

Properties of clays

PY Tite ssessiecascgaden casa saad
FAY TITO INCAS 2c: caine ceotacdesa seindin sieseeadcundss Sephaesae a ecaueta doe acer
Pyrometer, thermo-electric................cccceecee eee teee cece sects erceeen een eecues 37
Pyrometers.................c06, 31
Pyrometer, Seger.... 32
Pyroxene in clays... or 19
QUAN EE ee sines anak ea resrtce at nies 41
Quartz a8 a grog............00.. 182
Quartz determination 49
QUARTZ TN: GLAS. wesscescussemesesannnezses teumenarysanrasnetniy Hectares 18, 21, 28, 41, 42
Quartz in kaolin 116
Queenware clay 86
Radiolarian: Cla y-eicdeunesuryscomcinecinens stuntavtwe damea aad vue Pte 3GSteete MAES 158
Railroad cuts, clays sliding in.......0...... cee cnet ee nee eres 90, 94, 96
Randolph, Bibb Co., clays near......... 0.0.0 ccc ec eee eee e sees eee ees 90, 91
Randolph County clay. .........ccsecssccnsssesscceeseceveecetseneseaetensee seesaeeeenes 72, 73
te «¢ kaolinite 71, 72
ne ‘« mica veins 72
ee ‘¢ mica schists 70
‘¢ pegmatite veins 72
RatlOnal anal y SOs 522 deste ovsdinacs snian son vubeacameucoysawtninbadwadeeabeddngtirsneands 56, 57
ee BOP CIAY Bes. sccinsisepencinsnnaninaains mentnin vite 50, 54, 147, 149 150, 152,.154
ef BE OP KAO M scacscscaeine sence viareee usden Sune aetwueas mee recaatieaes 54
A “| Uses of. oe 56
Red burning clays.................... Iphayeseaietide a itacyeath ae daneene creersmeics a ae 59
Red clay, Lauderdale Co ‘112

Red Mountain, Wills’ Valley, clays
Red shale, Marion Co..............:cccceeeeeeeceeeee eee nneineeeeeeees
Refractory articles.................05

ee bauxite

“ce

Page.
Refractoriness in clays... cece cocccec esses eesneeseees AOA POF eI 51
“Refractory quotient? 0.0.0 oo ccccccccscsscccececececssasesesusceceteseseeees , 31
Residual clays 00.0.0... lc ccccescsccsceseusece vececceceeee seceeeeceses 5, 6, 13, 69, 73, 74
Rhea, Mrs. C., Colbert Co., clays from..................... supedd Manttanrattonte 110
Ries, Dr. Heinrich, general discussion of Clays DY: tscdiviaciesnerecncrionds » 38
ae sae ““ , physical and chemical properties of clay by........ 14
Boge oe “ , quoted......69, 70, 79, 81, 88, 89, 92, 93, 94, 97, 98, 99, 102, 103,
104, 109, 110, 126
Roberts’ Mill, Pickens Co., clay near.......0..6. ccccccscces coe bh 97, 170
Robinson Springs, Elmore Co., clay near............ccccc0.-.- 88
Rock Run, Cherokee Co., bauxite, refactory 142
‘Rock Run, Cherokee Co., clays near........ 74, 117, 118, 133. 136, 160
a <f _ ‘¢ kaolin near. 28
Rodentown, DeKalb Co., pottery and Clay DEAL... eee cece eens 80
Rollin’s, Thos., Franklin Co.. Clay .........ccccccccscsssceceecesceseeseeaceeceeee: 108, 109, 180
“Russell County clays.......00......0c0cccc. caeanvinswanannn ‘87
Russelville, Franklin Co.. clays near.......0.....cccssssseecesecseseceececees 108
Rutile (titanic acid) in claysy........0.0.ccccececcccescesencecesesevecseeseseeveeees 21
Rye’s pottery, Milldale (Detroit P. O.).....0....ccccccccccsesesessesssessseeseees 101
St. Louis fire clays, silica in... 0.0.00. cocecccccesccceessecesseeseceseseveeensens 20
Sand determination a 49
MSG 1M CLAYS acd esesiced eansegunstesace seeaneepnissa nate vd a nce os Some ten Gm woah 18, 20, 21
Sand, molding, Marion C0...0...0.....ccccccccccessesseeeeeseccccecceecescesteseeseens 105
Saunder’s Ferry, Tuscaloosa Co., clays near 95
Savoy P. O., Franklin Co,, clays near 108
Saxony clays and kaolin. ............c.cccccccccccsseeesccessscesssees 54
School House Hill, Centerville Co., clays in 91
Schists, mica................... us 70
Screening of kaolin , 65
Sections of clay beds and outerops.......... 77, 78, 89, 90, 91, 93, 94, 95, 96, 98, 99,
100, 102, 108, 104, 105, 109, 110, 111, 162
Seger cones (pyramids).................ccccscsscecceeeeesesnnneccceeeeeeeeenens tokens 32
“¢ quoted...... Feet I cd sity Ma Reyes SS aN yee Sth seen SNe td 15, 18, 21, 59
Sedimentary clays................c.cccccceee caeeceeaeetenesseeeeee adilbaedecee Seta eepsdds 5, 7
Semi-refractory clays = 131
Settling tanks..........0.......cccesecseeecceeceeeaeees is 66
Sewer pipe in U. S. in 1897 valuation of.............. ms 1s
MST) OB sibs ss 0 5 ganeneemiensety sues sie nc deta daca ine deeumtwaua aed ieumtntenaniateng onsets 7, 183, 184
‘Shales, Carboniferous, for vitrified and pressed brick, terra cotta. etc 80, 81, 105
Sheffield Paint Company, clay f.................cssseeecccecceeeeseeeeeeeeeeeeenens 112
Shewberry, quoted: ...ccrcccnwascatesunarawermameneeasdoadouns conmvades tandoassneneetoOs 200
Shirley’s Mill, Fayette Co., clays near ........0.... cece cece eens 103, 176, 184
Shrinkage in Clays.............0 0c: csceceeseseeeeeeeenteeeenees 18, 23, 24, 26, 56, 132
Silica determination 46
“for paint and glass manufacture 112
8 Dn Cla YS ise csvessaecscvrevieseeeeend andacnasdssentedeceedeSihs geneva dandy . 20, 21, 51
Silicate of lime in clays... . 22... cesses ce eeeeeereeereeee ees 17
Siliceous clays..... ................ 28
Siderite in clays 44

Sink hole clays... eidlelona te aca decease ahs Pi 73

218 CLAYS OF ALABAMA.
Page.
Sintering in clays 30
Silurian Clays...... cece ceceeceeceeeeeteeceeerseesnraees 73, 133
Sizemore, Ira, Lamar Co., clay of.......... .......... 101
SING. «cciicsssrasinaananasscacanewacaeawadicapeesyvaswenegae 38
ACG soe steasscnscaneciacnciasinggsmpascuaees oven dnorsddewaemess 8
Sliding cut, Tuscaloosa Co a 94
Sliding of clay sycscdissciscssvcnsacenceasuaas vvsenwaviseiascnensssecdsasteesees Luiiesneewons 90, 94, 96
Lip Plazes ssa. casei alesud wasesveeaweddeaaaun Ade sckltc sacdiens Laces tateeeasaneraansaac agentes the 17
Smith, Dr. E. A., geological relations of the clays of Alabama by.... 69
CTS (2) 1s Arr 18, 114, 158, 189
Snow place, Tuscaloosa Co., Cl@yS OD.......cccceecseeeeeeee eceeeeneeseeeeeene 95
Soap Hill, Bibb Co., section Of............:.:sssscnsseeeeeeesenseneeeeccceeeseeeen ees 91
Society Hill, Rassell Co.. clays near............... 88
SODA TH ClAY Gis. sissicisnccsevzes eesteavacedanendgaacans 11
“Soft Mud” process of molding bricks 182
Soluble alkaline compounds in clays...:. 11
Southern states, ferruginous Clays Of............0....cccsesessccseeeseseeeereneeee 5
Splitting: Of Dricks:.....icdoscice-0 tecvereeesaasnastgjeeawintsaendsasigeadeesaed dadesdaese sence: 17
Steele Bluff, Warrior River, clays at................ cee ceeneeeceeeeeeeeeeaees 96
Steven’s, Calhoun Co., clay.............:eceeeee eee : sitarteereeseese’ 183,184
Steven's Switch, Jefferson Co., Clay...............ceceeeeeeeeeeeseeeeeeeeeceeeeeees 80
Stewart's Cut, Marion Co., clay...... 0.0... eee eee saeanea aioe 104
“Stiff Mud’ processs of molding bricks 182
Stone Hill, Cleburne Co., clays near............0.cc cee eee ec eeeee ee eeeee eee 72
Stoneware, Clays...............::cceeeeee 79, 97, 159, 162, 165, 169, 170, 171,173, 178
ee Che nb POR gccaseacketmmmchosehesoss enneneeac sabe pas muasvaninnemetindes 79
“ IMAM UPAC UTS ocoosseccsssecuancgaineeeaece Ao dereapeonnaninetane meee 71
Sub-carboniferous clays........ Sete 77, 117, 133
Sulligent. Lamar Co., clay mear............0ccc. cecceeceeeeeeceeeeteceeseeaaaaeeenes 100
ee ee “pottery at apis seven ibaa x SiH 92, 100
Sulphur determination. ...........0.....ccccc cece ee ceseseeeeeaeeeeceseee aeaseeeaneeeeees 49
Sulphuric acid, free, im Clays. .......... cece cece eeeeeeceeeeteeeenreeeseees . 12
Summit, Blount Co., clay and pottery mear................ceeceeeeeeeeees 80
Swelling of clays........0...... cee cee cece ee eneeeseees a seein sale nremhesi ghana tan, 15, 17
Talladega County clays 76, 121
Tampa, Calhoun Co., clays Mear..........ccccccceccccccccceececeeceteeeeeeseeeeeesass 75.
ce a“ SE CEBOMD si shies wstincainetoaushvediweduuevesersn siinanieaesaneunes 74
Tanks, settling, in washing of clays 66.
Tan Yard Spring clay, Lauderdale Co.........c:ccccccecseessessseceeeeeceeeaes 111
Taste: Of, Cla YB: cisescciasercnaatiarenawarascan? /daiceuseaieved daeed daaiwaaun shawdaeedsalned seo 12

Tile, other than drain, in U. S. in 1897, valuation Of...................:566 1
_ Tishomingo County, Miss., Clays..............:ccccccceeseeeeeseeeeeecsaeeeeeeneneees 83.

Tuscaloose, clays at and near.....cc.cccccccocescccccsecceecsecceees 92, 93, 94, 96, 116, 202
Tuscaloosa County clays............. 92, 93, 94, 96, 152, 153, 166, 169, 184, 187, 202
81, 82, 117, 133, 160

Ultimate analysis... cc cccccccescsssccccacescsevavscsevens sesceasacaesceees 50, 51, 52

be “* of clays, see analyses of clays. ...........sesccssceee a

fs ‘of kaolins, see analyses of kaolins see
a BE fy BOS OL eset visas nccccx avon ven aniscneadcacesaduveateutisbunciensavten’ 51, 52
Underbeds to coal seams, Clay......c...ccccccccecesssessceccesseccescesseuseereeseeas ~ 80
United States Giological Survey, quoted......0..0.0cccccscssseseseeeesceeees 58
Utilization of Clays... cc cceccccssescseeesesscesecceecsvsccseseceeseeceessease 114
Utilization of clays for Portland cement.............00.¢ccecssccecsseeestevees 199
Valley Head, DeKalb Co., clays near....c..cccccsccsescce cescseccsecsseeeee 133, 146, 148
a ee ee £& KaOlin, Near ivescscessewesuagenecteeretianatantyecny 61
Valley Regions Reports, quoted.............:cccccccssseeseceeses 75, 76, 77, 80, 83, 110
Vance Station, Tuscaloosa Co., clay near..........00.ccccccccccceeeetteneeees 94
nt ib “ “pottery at... 80
Vaugn’s pottery, Elmore Co.............ccccsssssescesensneeeess 88
Vein Clave. sicsaskeaisaiewewsndcaereaennsecesenves 6, 70
SS VA OUMS aise vascastageean cuatacabs onacdadaehen 7, 61
Vernon. Lamar Co., clays near.............. sathege aneas ster 98
Vineton, Autauga Co., clays near 89, 90
Viscosity of clays.....0.....0 eee. iedhartanagy veeivaalsh tgreineeeasouses 30
VisCOUS. CIA YS: via sescneasanctyeacaaepatwndites eqperndeanipmaces aeasgunanes 30
Vitrified bricks. ........... 0.0 cccccceeeeeceeeeeeees 80
ee 5 Clay B: POP issciscseenevesscesesans 88
f «shales for 105
Vitrified paving bricks in U. S. in 1897, valuation Of..............0.:::0 1
“ware, clay for 10
Vitrification of clays...... 30
VOB, Gi, GUO LEG Saisie cise Maga avaadecacecngos ntelgsinhreoimentindereceecdineas se 53
‘Waldrop's, Fayette Cou, Clay vilveanswisscccnasedauesdaneasdentoeednsesinesetwgisecestes 103
Wallace’s Mill, clay near................ 102
Warping of clay in Durning..........00... 0. ceeeeseteeeeeeeeeeeeeeeeneeeanees 27
Warwhoop bauxite bank, Cherokee Co., Clay in............:c0s::eseeceeeseeee 76
Washer bauxite bank, Cherokee Co., Clay it...........:ccsesceeeeeseeeeeeneeees 76
Washing of Kaolin............. i eeeee se eeetess eee ees 62
Washington County flint clays 181, 158
Water 1D CA. icccciccccsieisscwecndsssnsivvscctecne’s 22, 45, 51
Water (combined) determination 45
a " Atl Cla VGs ce ssecanecsacesscavewcnenns 61
Waterloo, Lauderdale Co., white silica from... 112
cowWater Smoking” ...............cccccccccceesseeeeceaveceen 23
Wedowee, Randolph Co., clay near............... 73.

220 CLAYS OF ALABAMA.

Page.

Wheeler, H. A., Clays of Mo., quoted.............cccccccccccesecccseeces sanseeenees 4, 30, 31
White and yellow burning Clays.............ccceccccccccccceeeassseecenseceececeeees 58, 59
White, F. 8., clay from Blount Co., from...............ccceeecccsenceeeeeeeeeneee 160
White mica:it) Clays iscsi. seen: cudeacud gerncexoodansaaneaiaee sna geearevediss adi weeuenecs 43
White Bluff, Warrior River, clays at............. ce cceecceeeecneee reer tenes 96
White ware ClayS.............::cseseseeee plete uate. 125, 130
a © MIXtULE....... eee eee eens «116, 117
Whitewash, clay used as a 85
Wiggins, Henry, Fayette Co.. clay in bored well of.... 103
108, 178

Williams, J. W. Colbert Co., clay Off..........:0:ccsseceeesensceeecceessanertaeeeenes 157, 180
Williford’s landing, Warrior River, clay at 96
WUIES, Valley Clay sisi .0ccccnsdanisassctosencapesoveceneusbiciinesissccvedssoueceave 77, '78, 79, 117
Woodbridge fire clays, silica im..............ccccccecceeeseee ceeeerseeseeeeeneeeeeees 20
Woodstock, Bibb Co., clay mear...............e eee 92, 133, 134, 151, 184, 191
Works, Bessemer, clays for fire brick 109, 150
Wright’s P. O,. Lauderdale Co,, clay near.............ceeceseeeceee ceeteees 111

Vellow Durning Clays iis io: sescecdicinedieesaciovadeidonmiiecacnmssataaaeiee wedaddedaatcce i 59