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15G1 N. Danville St., Arlington, Va. 22201 

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A ramphlet describing the most reliable indications and the 

principal minerals associated with the 





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PRICE 5s. 





.;•-■,.-:, ■/>■■■ J. ■ 

Mr. W&WEm DR4PBR, 

Fellow of the Geological Society of London. 
Member Fed. Inst.Mming Engineers" Forth of England. 

Member Geogr. Soc. of Holland. 
Hon. Secretary Geological Society of South Africa 
Curator Chamber of Mines Mineral Collection 

London Office : 



South African Address : 



Mr. 1€ . 

Who has been for many years connected with Diamond and Gold 

Mining m the Free State and Transvaal, will inspect 

and report upon Mineral Properties in 

any portion of South Africa. 


Extracts from Local Press Reports : 

" Mr. Draper identified the specimens fr m Riotf„nf^;„ i • ■■ 
iferous, in February, 1897."-* «»« IT^XZ^g, &£ {&?»*■ 

"The lessees of Rietfontein were invited to not fo« n i . 
to their a tonishn,, n , they wereins.rucMed by a S « ,™ tXt ""I 

search for the precious mineral, whose efforts tknnl . T i Kietfontem) to 

gratifying!, successful, ano haie placed bey !„,? do^bt !,* Wi,Th 6 ' "T 
ex^ence of a ,rue diamondiferous pipe in tL T^^l]^^ *%;*£ 

The owners have acknowledged that Mr. Minett R Frames found 

the first diamond at the Rietfontein Mine, in 

the washing' operations. 


, -U- . fV>n ii,<Kt reliable indications and the 
A Pamphlet describing the mo*t lenauu 

principal minerals associated with the 










<• |,, , » 




To the great amy of prospectors whose efforts have d.-c 
s0 much towards the development of the unneral resources o 
South Africa, this little work is respectfully dedicated by the 
an SI in the hope that each one who purchases a copy .ill 
discover a diamond mine and make his pile. 




In placing this pamphlet before the public we do not pose 
M phnaStopist. Whave had a ^r amount of expem-cn 
diamond rnininc both on the River and at the L>ry L>ig n e > , 
SSSe impression that those who do not know what 
a rough diamond is like, or are ignorant of the , ar ^r ot tfte 
mine&l in which these gems are found, and the ™»£F£ 
which have hitherto led to the discovery ^J^PgSffi 
will gladly avail themselves of the hints contained in tl us nttte 
wok When we were prospecting in tje ea riydays ofjhe&a- 
mnnfl industrv we would have paid a great deal more 
iCn the mce asked for a work containing the same amount of 
InSr We believe that old diamond miners may also pick 
up a few hints from a perusal of these pages. Very Jew men 
have visited all the diamond mines in South Africa as we have 
done and noted the peculiarities ol each one. . - 

TIipii ftffain evervbodv does nol know what a diamond is line, 
„or tow t ^/for it,' though old hands will »***£. Jj§ 
"uperior knowledge and tell us that '• no man can be m ^taken 
be has once handled a few diamonds. But this is r>> "°. uu .* 
the cSe as the history of the famous Monastery /.neon will tell. 
n Snlnce experienced diamond men were ^J«V»J 
some even offered large sums ol money for a comparativelj vaiue 

^ W^have advised prospectors to proceed on the lines we 

the New Rush (now Kimberley Mine) on the day thej were 

given out, and worked for several years thereon 

Mr Frames mew up on the Diamond I ieltts, ana was con 

tunitv of making the fact public, were led to the wentmcOTion 
Kg diamond bearing mineral, by the occurrence of the various 


minerals which accompany the diamond in every mine in South 
Africa ; and so once more the " carbon," " garnet," and " neeu 
stone have done good service in the development of the mineral 
resources of this country. 

We were told when we first made this discovery pnblic that 
blue ground had never been found on the surface, and that 
Ivnnberley and the other diamond mines were covered with lime 
and Rietfontein, Pretoria, was not, consequently it could nut 
possibly be a diamond mine. But we pinned our faith on the 
diamond s inseparable companions, and they have not failed u.s 
1 he now recognised importance of Rietfontein is therefore 

Sect* P WG WerC entitIe<l t0 Sive an °P inion " 2K 

The fact that diamonds existed in the Transvaal has been 

public property for a number of years, but hitherto the home of 

these valuable gems was a mystery which we have succeeded in 

That the Rietfontein Mine, Pretoria, should have been nros- 
pected. for coal firstly, and later on for mercury, is aifothe proof 
of the ignorance of a great number of men who pose as author? 
ties upon the indications of the diamond. It will not be believed 
by old diggers that shafts were actually sunk to 35 fee? in 
blue ground," without the prospectors discovering he value of 
the spot they were working, yet such was the case. 

jr ^^r^svris^s^: =5: 

In TOidusion, we woold adTiae those who wish to beenino 
thoroughly aeyamted with the diamond bearing mleS, of 

oomph* ooileotion e, ^JT ft* ^eStbT'K 

David Draper. 
Minett R Framed. 




(Jolo,,bedPt ' atkNo - 'chapter I. 

What is \ DlAMOKD.— Colour and Composition, Form, 
Hardness, Lustre. Summary of its principal chare*- 

Boart, Carbon or Carbonado ... 
How to identify a Diamond ... • • • 

Minerals whicb may be mistaken for a Diamond ... 

Minerals which are found in company with the 
Diamond in South Africa ... 
The Garnet, Carbon ... 

Olivine, Mica, Vaalite, &c. ... 


The Diamond Deposits and Rocks 

Section 1- -The River Gravels ... -• 

Section 2— The volcanic pipes or chimneys known 

as the dry diggings 
Yellow ground and Blue ground... 

Hard Bank ... ... ••• 

CHAPTER IV. ... - 

Geological position of the various I^mohd Mines 
Rietfontein, Kimberley and De -Beers I late, 
Jagorsfontein, Kaalvalley (Robinson's), Dnekoppies, 

Monastery, Carnvel ;; 

CHAPTER V. .- .» 

Bribe description of the different Diamond Mines 


Bultfontein ... - . ••• 

Du Toit's Pan : Jagersfoutem ... 

Old De Beers— Kimberley 

Koffyfontein— The Monastery ... 

The Robin 8 on.Rietfontem p ^ ... 

How to prospect for Diamonds and the Plant required, 

by M. E. Frames ... ... 


Where to search for Diamonds 

Conclusion ... 
A few hints to Prospe< tors 

P^LLw forthe regulation of Diamond Mining in 

South Africa, Weights used for precious stones 

Hardness and specific gravity tables 


• » t 
















Plate 1 





Fig. 1. 

Piece of Hard Blue Ground, with Diamond and Characteristic 

Minerals in Natural Colours. 

South African Diamond Octohedron,^ copied from 

" Dana's Mineralogy." 


— I 


Chapter I. 
There are three varieties of the Diamond- 
The Gem ok Precious Stone. 


Carbon or Carbonado. 


Colour and CoMPOsrriOK.-The diamond is a precious 
stone, generally white or colourless, though found of Sat 
tan s ranging between white and black, but of which pa le yeUow 
or straw colour 18 the most frequent (after white and colourS ! 

Red, orange, and blue diamonds' are rare, but *moky or 

g ?t ,nl Z freqUent,y fonnd > b,ue » most uncommon' 

ihe colourless stones are almost, invisible in clear water 

If a diamond is colourless and free from flaws and spots it ia 
called a « first water stone " and is of the highest value in pro 
portion to its weight and shape. P 

The diamond is composed of pure carbon and can be com 
pletely burned to carbon dioxide (carbonic acid gasO between the 
poles of a battery, leaving no ashy residue behind 

»A a >' S m l imhle < but whe » exposed to great heat in an atmos- 
phere free from oxygen, it swells up into a black mass like 
graphite or coke. It is also unaffected by acids 

Its specific gravity is 3.5 (3* times heavier than water). 
U«A "**— Diamonda are found in a crystalline form • octa- 
hedrons or eight-sided stones are the most numerous A perfect 
octohedron has eight flat sides or « facets," each of wild Eld | 

somewhat! ^SLSEa^x ***** ^^ these fawts ™ I 

Stlyturtd 6 ,U Sl ' aPe ' a " d thG a " gleS and Sides ™ I 

Some diamonds have their facets marked with small tri- I 

angular indentations as shown in figure 1, plate 1, which repre- I 

sents the form and mode of crystalization of a perfect I 

octohedron. The drawing is copied from Dana's Mineralogy I 

10 Til E DIAMOND. 

Other forms of crystalization occur, but they are all modifica- 
tions of the octohedron. Diamonds are never found of the same 
shape as quartz crystals, which have six sides and six triangles 
converging to a point, either at one or both ends. 

Hardness, -Though several of the harder minerals wil 
scratch glass, only the diamond will cut it. Glaziers diamonds 
are thosl having an acute angle, selected on this account because 
they cut glass more effectively than ordinary diamonds would do. 

In the scale of hardness the diamond ranks highest, corun- 
dum being the nearest to it, topaz and quartz following in succes- 
sion. Consequently a diamond will scratch all other substances, 
but cannot be scratched by any other mineral except a diamond 

It is possible to cleave a diamond along certain planes (with 
the grain), and it can be crushed by a blow with facility. 

Many good gems were lost in the early (lays of diamond 
mining is South Africa by what was called the "anvil test 
which consisted of placing the diamond upon an anvil and strik- 
ing it a smart blow with a hammer. Naturally, but a small cone 
of dust remained behind. If a stone stood this test it was sup- 
posed to be a diamond, but there is no instance recorded of any 
one surviving such rough treatment. . 

Lustre. Even in its rough or uncut state, a pure diamond 
is generally so lustrous that it can easily be distinguished from 
among a cluster of clear quartz or other glittering Btones. It has 
a lustre peculiar to itself, which once seen is not readily tor- 

§ ° tte Occasionally diamonds are found which have a dull coating 
or covering. These are often of a good shape, but close examina- 
tion is necessary to detect the lustre beneath the skin. 

In addition to the peculiarities above mentioned, a diamond 
has a soft soapy feel, which is so noticeable that experienced 
men can distinguish these gems from any other by the sense of 
touch alone. Even the fragments of a diamond show this feature in 

a marked degree. , , .. ^. 

Quartz crystals are rough along the edge and even the topaz, 
which is often mistaken by the inexperienced for a diamond, is 
rough compared to the latter gem. , 

8 Diamonds are frequently found in fragments (chips and 
•cleavvage) of all shapes, sizes and colours, but with the excep- 
tion of shape the above description is applicable to these equally 
as well as to perfect stones. 



Colour.— Prom white or colourless passing through yellow, 
red, orange, green, blue, or brown to black. The three first- 



mentioned colours are common, the others rare. It is also trans- 
parent and translucent. 

Form. Octohedron (eight-sided), dodecahedral (twelve- 
sided), most frequent, but mackle or flat twin crystals are some- 
times found, and in all mines a proportion of the diamonds are 
found in a fragmentary form, known as chips and cleavage. 

Hardness. — Exceeding that of all other known substances. 
The nearest to the diamond in hardness is corundum or emery, 
the topaz and quartz following in succession. Consequently the 
diamond will scratch all other minerals, but cannot be scratched 
by any of them. See Hardness Table. 

Lustre. Most noticeable in clear stones of any colour, 
but occasionally obscured by a thin skin or covering. 

Note. — A piece of clear alum, filed to the shape of a diamond, 
and then sucked for a few moments, is a very good imitation, 
in colour and lustre, of a good white stone. 

Gravity. Exceeding that of most other gems, but less than 
that of the sapphire, topaz, zircon and garnet. See Gravity Table. 

Electrical Properties. — Negative, but becomes electrical 
by friction and will retain this property for about thirty minutes. 

Feel. -Soapy to the touch. This is most marked, and is a 
characteristic belonging solely to the diamond amongst gems. 


Boart is generally of a greyish or lead colour, has a rounded 
form, and often a number of small fragments are aggregated 
together, forming clusters, or enclosing crystals. Its hardness 
exceeds that of the diamond itself, slightly, but its specific 
gravity is less : 3.15. It has a greasy lustre, and is smooth to 
the touch like a diamond. Boart is occasionally found in lumps 
of considerable size. Kimberley Mine produced a piece over GOO 
carats in weight. 

Crystals or fragments of crystals useless as gems are alsQ 
■called boart in the diamond trade. (Dana.) 


This mineral has not yet been identified in the South 
African Diamond Mines. What is called carbon here is in reality 
either ilmenite (titantic iron) or magnetite (magnetic iron). 

Brazilian carbon is massive with crystalline structure, some- 
times granular to compact, without cleavage. Hardness is greater 
than with the crystals (of diamond) and it is less brittle, its 


specific gravity is less, due in part to slight porosity. Lustre 
resinous to adamantine, colour black or greyish black. It is 

Found occasionally in large masses up to 731 carats. (Dana.) 

There are gradual transitions from the perfectly crystallized 

diamond through various forms imperfectly crystallized or made 

up of several individuals to [the true boart, and again between 

the boart and carbonado, 


The first test to be applied to any stone which may be con- 
sidered a diamond is to try its hardness. For this purpose a 
glazier's diamond is of great service. If the stone can only be 
scratched by exerting considerable pressure, the probability is 
that it is the gem sought for, but in order to decide this point 
definitely, it will be as well to apply a few more tests. The 
gravity may be approximately ascertained by dropping ^ the 
specimen into a small phial containing about loz. of " Gravity'' 
solution This most valuable solution, useful for determining 
the comparative gra\ity of a great number of m'nerals, can 
be obtained from Messrs. Taylor & Co., chemists, Von Brandis 
Square, of any required density, prepared in ounce bottles. 
It is a strong poison and must be used with great caution. 
The method" of determining the comparative gravity is to 
drop the mineral into the solution ; if of greater specific gravity 
than the liquid it will sink to the bottom, if of less it will float. 
For testing the gravity of diamonds the solution should have a 
sp.g. of not less than 3.1. If the specimen floats on the surface 
of the lquid it may be discarded as worthless If it sinks to 
the bottom rapidly it is either a diamond, sapphire, topaz, or a 
zircon, but if in addition to its sinking in the fluid it will stand 
the hardness test, no further examination will be necessary — 
it will prove to be a diamond right enough. 

Both the topaz and zircon are soft compared to the diamond. 
The former is 8 in the scale of hardness, the zircon 7.5, the dia- 
mond 10. 

Another test is its electrical properties. A diamond becomes 
strongly electrical when rubbed, and will then attract light ob- 
jects, such as a small piece of paper. Other uncut gems do not 
exhibit this property. 

The sense of touch plays a considerable part in the identifi- 
cation of a diamond, but experience is necessary before this can 
be relied upon. No other mineral crystal feels so smooth and 
soapy to the touch as the diamond, even if in a rough state or in 
1 its most fragmentary form, as well as when in the shape of a 
most perfect ciystal 



_ ?° gUi i e Ca ? v e give ? with re « ard t0 colour > though the 
greater number of diamonds are white, colourless, or yellow. 



Quartz.— This mineral crystallises in a different form from 
the diamond. When perfect, a quartz crystal has six sides, and 
each end has six triangles (generally varying in size) which con- 
verge into a point. It is much softer and lighter in gravity It 
can be scratched easily with a glaziers diamond, and will float on 
the surface of the " Gravity solution " of a gravity of ?,A. See 
Gravity luble. 

It has not the lustre of the diamond, though exceptional 
crystals of quartz are lustrous to a considerable extent. 

Topaz.— Is equal to the diamond in gravity, but can be 
scratched with ease by a glazier's diamond, and though colourless 
is generally deficient in lustre and is Hat in shape. 

The Zircon. -Is much heavier than the diamond, is lustrous 
to a marked degree, but is rarely white, generally light yellow 
and can be easily scratched with a diamond. 

Note. -A stone found in the Monastery Mine was so like a 
diamond m shape and lustre, that it puzzled a number of ex- 
perienced men. On the tests of hardness and gravity ilTfailed 
utterly, and was found to be a zircon. 


Chapter II. 



Diamond!? are mined in two different classes of rock :— 
1st The alluvial gravels found along the hanks of the Vaal 

River and some of its trihutanes. 
2nd. The volcanic pipes containing the mineral known as 
" Kimberlite." , , . ... , i , l4 . 

These are so distinct from each other that, they wiU be dealt 
with separately later on, this chapter being devoted to a bnet 
dSripSon of the chief minerals which accompany the diamond, 
both in the river gravels and volcanic pipes. 

Foremost amongst these is the beautifully coloured garnet 
without which the diamond has not yet been discovered here 

Composed of allumina and silica, tinted by per-oxide of 
iron, these stones, which on account of then- beauty, ma) almost 
be classed as gems, are of a deep red colour generalh , though 
there are varieties such as Essonite, called cinnamon stone on 
account of its resembling that spice in colour ; Grossulante 
which is green, and several others of different colours. 

Those found in company with the diamond arc generally o 
a deep red colour, and belong principally to the variety caUed 
« Pyrope," and are frequently much rounded .n» though the) had 
been subjected to a considerable amount ol friction. Th»w • 
peculiarity of this variety of garnet. It is found in the Tvrol of 
the same form, and also accompanying serpentine rocks, as in the 
diamond pipes of South Africa. Garnets are abundant m the 
volcanic pipes, but less so in the alluvial deposits. 

CAEBON— This name was given to the small black fragments 
of ilmenite which are found accompanying the diamond. It iw a 
black mineral, glossy where fractured, occurring somet nuts in 
distinct cystalline form, though generally fragmentary It! hasa 
cferoncttdal (shell-like) fracture, and a specific gravity surpassing 
that of the diamond (4.5). „ . f j- 

Occasionally, as in the Monastery Mine, carbon is found 
in nieces of over one pound in weight. , 

P The mineral called " carbon " here must not be confounded 
with the true " carbon " or " carbonado which is found m the 

Brazilian Mines. , , • t 

f he latter is of sufficient hardness to be employed in rock 
drilling, whereas the former is a soft and brittle mineral, tor 
which no use has yet been discovered. 

I I 




Olivine (green stone of the miners) An emerald green 
stone generally found in small fragments only, but invariably 
accompanying the diamond in the volcanic pipes. It can be 
scratched with a knife, is brittle, and has a sp. gravity about 
equal to that of the diamond (3.5). 

MlCA.-— A variety of Mica called " vaalite " in mineralogy. 
This mineral was identified in the diamond pipes of South Africa 
by Messrs. Maskelyne and Plight, before whose discovery it was 
unknown ; the name " vaalite is after the Vaal River. 

It differs from other micas in several important respects 
which were considered sufficient to entitle it to a distinct name. 

It is of a brownish colour, not yellow or black like" phlogo- 
pite" or "biotite," and it also differs from the variety known as 
'• muscovite," from which the large sheets are obtained. It is 
generally intersected by a large number of fine lines running 
parallel with each other, and occurs in small plates only ; these, 
however, show a distinct lamination similar to that of the other 

Magnetite or magnetic iron is also found in the diamond 
deposits of both classes. It cannot readily be distinguished from 
the mineral called " carbon ' though it is duller in lustre and 
often cubical in form. 

In the alluvial gravels many " agates," " carnelians," " cats 
eyes," and stem-like " zeolites " are found in addition to the 
minerals already mentioned. Most of these appear to have been 
derived either from the decomposition of the diabase amygda- 
loids, through which the Vaal River travels for a great number of 
miles, or from the destruction of the pipe " amygdaloids of the 
Drakensberg, which would free the stem-like zeolites. 

The matrix which contains the diamond and associated 
minerals in the volcanic pipes, is a variety of serpentine derived 
from the decomposition of a rock rich in olivine and known in 
mineralogy as " Kimberlite.' 


Chapter III. 




Diamonds were first found associated with certain isolated 
patches of gravel along the banks of the Vaal and Orange 

The principal of these were situated below the town of 
Christiana on the Vaal, and near Hopetown on the Orange River 
though occasionally diamonds have been picked up as high up the 
former river as Boshoff. Many patches of diamond bearing 
gravel were found near Klipdrift (now Barkly), and on the Pneil 
Mission Grounds on the Free State side of the Vaal River. 

There are also isolated patches of gravel in which diamonds 
have been found on the Modder River below its junction with 
the Reit, and also in the bed of a small creek which enters the 
Sand River, near Rheuoster Kop, in the Kronstad district of the 
Orange Free State. 

River gravels produce diamonds of great purity and good 
size, but the yield is comparatively low and the finds most erratic. 

Few fortunes have been made at the River Diggings, and 
there are not many miners at work on the river at present. 

There does not appear to be any true indication of the pre- 
sence of the diamond in the river gravels. Carbon and garnets 
occur, but in lesser quantity than in the " dry diggings." ^ 

River miners will explain the peculiarities of the diamond 

bearing gravels as distinguished from the barren deposits, but 
these indications are more imaginary than real, and are of little 
value to the prospector. 

As the river diamonds were probably derived from the des- 
truction of a diamondiferous pipe, situated somewhere in the 
river channel, it is natural to assume that the diamonds will be 
most unevenly distributed and be associated with any alluvial 
deposit which has lodged along the banks of the stream. 

The stones generally accompanying the diamond in th 
alluvial gravels are described in chap, ii., page 14. 





The bulk of the diamonds found in South Africa are derived 
from the volcanic pipes or chimneys which are found scattered 
About the country. 

These occur in different geological formations and are 
not confined to any particular stratum or period. 

They are generally irregularly circular in shape, of 
limited extent and surrounded by barren country rock. They 
are true volcanic pipes and chimneys, which have served as the 
vents for the passage of molten or muddy material from 
subterranean reservoirs. 

The theories of the formation of diamonds form a most 
interesting subject, but one which cannot be dealt with in so 
small a volume as this, nor are they of any practical interest 
to the prospector. 

What he has to deal with is the economic side of the ques- 
tion. For his purpose the following description of the mineral 
will be of more service. It is, however, somewhat difficult to 
describe the peculiarities of the diamond bearing mineral in such 
language as will be easily understood by those not accustomed to 
mi nero logical terms. 

Firstly it must be understood that the different diamond 
mines, though situated many miles apart, all contain the same class 
of mineral which is known as " Kimberlite ' by mineralogists. 

In all the know r n mines there is a distinct difference between 
what is known as " yellow ground ' and the " blue." The former 
is situated near the surface, and is in reality the decomposed or 
much weathered portion of the " blue," which again is the 
partially weathered form of the extremely hard mineral —of the 
same composition as the " blue,' but much harder -known by 
diggers as " hard bank." 

' Hard bank ' is no doubt the original and true diamond bearing 
rock. All these varieties occur in the different mines in greater or 
less proportion. In the Kimberley Mine the blue was struck at 
about 100 feet, and the diggers thought they had reached bed rock 
when they found so great an alteration in the mineral they were 
operating on. In other mines the depth varied with the amount 
of decomposition to which the mineral had been subjected. 

In the most recent discovery, " Rietfonteift," the yellow 
ground is limited to a few feet in thickness. 

In their order of occurrence these different stages ol the 
^diamond bearing mineral will be described. 



As its name denotes this mineral is of a light yellow colour, 
easily crushed to pieces in the hand (incoherent), made up prin- 
cipally of decomposed olivine and other serpentinuous matter, 
and it invariably contains garnets, carbon, a peculiar brown 
mica (Vaalite) in small flakes, an emerald green mineral known 
by the diggers as olivine or " green stone." All these minerals 
may be in small fragments scarcely discemable to the naked eye, 
or in large lumps the size of walnuts or larger, as in the 
Monastery Mine. 

If a piece of yellow ground is cruslied between the finger 
and thumb and rubbed for a few seconds a peculiar greasy feel is- 


Though several minerals give the same results, they are- 
generally laminated, like mica shales, or leafy like talc, whereas 
the " yellow " is earthy and massive and does not show any lines 
of stratification or bedding. 

If the prospector finds a deposit of mineral which is not 
stratified but massive, is of a light yellow colour, has a greasy 
feel when crushed in the hand, contains garnets, carbon, olivine, 
and thin small scales of brown-coloured mica, he may proceed to 
search for diamonds with a good prospect of finding them. 
Naturally it is by no means absolutely necessary that all of these 
minerals must be present, but there does not appear to be one- 
mine in the country in which they are not found accompanying 
the diamond, and consequently, as they are in all cases, far more 
abundant than the diamond itself, they will be more readily 
found, and therefore can be taken as a fair guide to the position 
of a diamond pipe. By the aid of these indicators the Rietfon- 
tein pipe and several other diamond mines were discovered. 


This i« in reality the same mineral as the " yellow ground," 
but it has been less affected by the action of the weather, perco- 
lating waters, and other agents of decomposition. It contains the 
same minerals, though in the blue the different fragments of 
mineral matter can be more plainly distinguished by the naked 
eye. It is, as its name denotes, of a bluish colour when fresh, 
but changes to grey upon exposure, and it also crumbles to pieces 
under the influence of the sun and rain, or when exposed to the 
atmosphere for a length of time, varying with the stage 
of decomposition it is in. It contains all the minerals 
which are found in the yellow ground, garnets, carbon, olivine, 
mica, and it has the same greasy feel when rubbed in the palm, 
of the hand. 



It is rarely exposed on the surface of the ground, but occurs- 
at a depth which varies in every mine. The Rietfontein Mine is 
the only one in which the blue was found actually outcropping on, 
the surface. 


See plate 1 , fig. 2. 

This is the parent rock in which diamonds are contained. 
Blue and yellow ground are hard bank in different degrees of de- 
composition. It contains the same minerals in a fresher or less 
decomposed condition than they are in the yellow or blue 
ground. There is also a peculiar zoning of all the minerals in 
the " hard bank " which is noticeable to a lesser extent in the 
blue, but is absent in the yellow ground. That is to say, each 
different fragment of mineral matter of any size is generally 
surrounded by a ring or zone of a different colour composed of the 
altered mineral itself. A fragment of olivine is surrounded by a 
zone of serpentine (altered olivine). A fragment of diabase is 
surrounded by decomposed diabase, and so oir : so that the 
mineral appears as if it were composed of a number of rounded or 
subangular fragments each with a ring surrounding it. 

The greasy feel is absent irr hard bank, because the mineral 
is not sufficiently decomposed. 

Every diamond bearing pipe contains numerous fragments, 
and in some instances large boulders of foreign material, hardened 
shales, sandstones, igneous rocks, and occasionally granite. 
Many of these have evidently been carried up during the ascen- 
sion of the original mass, but some, such as the shales, appear to 
have tumbled into the pipes from the strata surrounding them— 
while still their contents were in a semi-liquid state. 

All these foreign masses have undergone a certain amount of 
alteration, especially round their edges. 

The Kimberley Mine had a large mass, composed principally 
of shale, similar to that surrounding the mine, situated near its 
centre, and continuing downward until the blue ground was 
reached, when it disappeared, (See section of Kimberley Mine). 
Very few diamonds were found in the blue ground with which 
these masses of shale were mixed up. 


Chapter IV. 



The gravels in which diamonds are found along the Vaal 
River belong to deposits which are slightly older than the gravels 
of the present river bed, and they probably represent the position 
which the stream occupied in past times, before it had excavated 
its present channel. 

No animal remains or other evidences have been found by 
which their age could be identified with any degree of certainty. 

The pipes or chimneys in which diamonds occur lie in strata 
of different geological ages. The last discovered — the 


— is situated in an older series of rocks than any of the 
other mines. 

Outcropping in a stratum of the Magaliesberg quartzites, 
by which rock it is almost surrounded, it is associated with what 
is generally supposed to be carboniferous rocks, though they do 
not contain any coal beds, but insignificant layers of graphite. 
These do not, however, come to daylight in the vicinity of the 
mine, and their nearest outcrop is apparently the Wonderboom 
Poort, near Pretoria. 

The Rietfontein diamond pipe is especially interesting as 
being the first diamond mine found in the Transvaal, the furthest 
in distance from the Kimberley group, and to its being situated 
in an older geological period than any of the other mines. 

In geological position the group of diamond pipes of which 


are the best known, are the next in upward succession. 
They are situated in the lower portion of the Ecca or Lower 
Karoo beds, which series is, however, of no great thickness 
there, dwyka conglomerate and Qtiartzite occurring, the 
former at a depth of about GOO feet and the latter at some dis- 
tance lower dovyn. Several of the pipes in the Kimberley group 
were covered with limestone tufa. This was especially the case 
with regard to Kimberley Mine itself, and Wesselton, near Du 
TohVs Pan. 

When, however, the fact is taken into consideration that the 
^western portion of the Orange Free State and Griqualand West, 
is to a large extent similarly covered, this occurrence of lime on 
the surface, and overlying the diamond mines, is of no consequence 
so far as the mine itself is concerned, though it adds to the diffi- 
culty of prospecting and hides the diamond pipe from view. 


Plate 2. 



iPE Amygdaloid 

Cave: Sandstone an. 
Red Beds Beds 


jr=J-zr-J-~-rr3 Ecoa Beds 



lwyka 1 


Quartz itcS 



Schist S 

Uncon fqrmity 


1 2. 3. 4. 5. 


3. Jagersfontein. 

4. Robinson. 

5. Monastery. 












Special mention is here made of this lime deposit because there 
appears to be a general opinion that a diamond mine must 
necessarily have such a covering, and the Rietfontein discovery 
was regarded with scepticism because the lime was wanting 
thereon. & 


t Beaufort beds are the prevailing rocks near Jagersfontein 
which is consequently associated with a younger period than 

In the next series in upward succession there is the Kaal 
Valley group (Robinsons) and the Driekoppies Mine in the 
KronstaH district. 

Coal beds outcrop in the neighbourhood of both these mines 
and fossil evidence as well as characteristics of the rocks point to 
the Molteno or coal bearing strata as the system with which thev 
are associated. 

™^T F , iim]ly ' the M0NA STERY and its neighbour the CARMEL 
MINE are both in the lower or red bed portion of the Cave Sand- 
stone period, and consequently appear in the .youngest sedimentary 
beds on the plateau of the Orange Free State. The Monas- 
tery is higher than any of the other mines. It 
is 5,700 feet above the sea, Rietfontein being 5,000 feet Robin- 
sons about 4,G15, Jagersfontein 4,750, and Kimberley about 
4,012. J 

t It will be seen from the foregoing that diamond mines occur 
m Southern Africa in all geological periods ranging between the 
Devonian and the Cave Sandstone or Jurassic. That they are 
confined to no particular stratum or series, nor are they asso- 
ciated with any one sedimentary bed, geological horizon or alti- 
tude. They occur scattered about the country with nothing 
definite to guide the searcher as to their position, except certain 
peculiar mineral features or minute fragments of the minerals 
found in company with the diamond. 

When the earlier discoveries of diamond pipes were made 
there was a tendency on the part of the miners to limit the possi- 
ble area < ver which diamond mines would be found to a small 
circle round Kimberley. The discovery of the Monastery Mine 
has placed beyond the region of doubt the fact that a diamond 
mine may occur in any one of the strata which is iound lower than 
the pipe ajnygdaloid of the Drakensberg, and this increases the 
prospecting area to a practically unlimited extent- 
Rumours of diamond mines being found in the Waterber<* 
and Zoutpansberg, have undoubtedly a foundation of fact to sup* 
port the many stories which are brought down from those parts- 
by prospectors, and there is every probability that these gems 
will be discovered there in the near future. 



Chapter V. 




The existence of diamonds in the area lying between the 
Vaal and Modder Rivers was discovered through the farmers 
being induced to collect stones and submit them to the inspec- 
tion of Mr. Hond,who was under the impression that the diamonds 
in the Vaal River gravels were derived from some centre which 
would prove to be a mine. Amongst the collections was a couple 
of bottles full of pebbles which had been picked up near the 
homestead on the Farm Bultfontein. These were submitted to 
Mr E E Hurley, Jacobsdaal, and Mr. Hond discovered therein 
one small diamond. A week later Mr. Lilienfeld, together with 
Messrs. Hurley, Hond and Webb, purchased the farm, and the 
public were allowed to search for diamonds on the surface, 
where fragmentary and imperfect stones were discovered m 

great quantities. ... 

The Bultfontein Mine, from the surface downwards, is simi- 
lar in many respects to the other leading mines of the Ki mberley 
oroup, in having a few patches of lime tufa underlying the red 
surface soil. The vellow ground continued downwards for about 
100 feet in portions of the mine. The notable characteristics of 
the Bultfontein Diamond Mine lies in the preponderance of 
garnet and greenstone rather than of carbon ; the latter is plenti- 
ful, however, as is also topaz (Dutch Boart), agate, carbon, and 
numerous crystals, are found. The yield ranges from 7 carats to 
40 carats per 100 loads. In general appearance a large number 
of the stones found at Bultfontein are octohedron m shape, and 
frosted in appearance. To a novice a parcel of Bultfontein dia- 
monds would appear of very superior quality owing to their 
whiteness. Closer examination shows that the majority of these 
white stones are spotted, and their value much lessened in con- 
sequence. Owing mainly to this detrimental feature Bultfontein 
diamonds usually fetch a lower price all round than those from 
other mines of the Kimberley group. Large diamonds are also 
rare at Bultfontein, seldom occurring over 50 carats in weight, 
and then generally of a straw colour. As in all diamond mines 
the ground is very patchy, certain portions of the mine are rich 
in diamonds, whilst others in close proximity are poor. 

In the extreme north-east corner of the mine the yellow 
ground was extremely poor, and the quality of the diamonds bad, 





whereas a hundred yards to the south or south-west, the yield 
was from 30 to 40 carats per 100 loads and the diamonds of good 
•quality. This serves to demonstrate the important fact that no 
particular spot can be accepted as a true indication of the average 
value of a diamond mine, and suggest to the prospector the ad 
visability of sinking holes or shafts in all quarters of the mine 
before giving up all hope of success. Patchiness is a characteris- 
tic of all the diamond mines of South Africa. 


This mine lies immediately eastward of Bultfontein, and it 
is probable that the separation of these two mines are more 
imaginary than real, and that they are connected underground. 
The diamonds found in this mine are generally good in shape, 
free from flaws, but of a bad colour. The deposit differs but 
little from that of Bultfontein, and the blue ground was reached 
.at about the same distance down. The extent of this mine ex- 
ceeds that of any other diamondiferous pipe, and it is question- 
able whether its limits are rearly known even yet. It is very 
irregular in shape. 


The discovery of the Jagersfontein Mine was prior to that of 
Kimberley, but as the owner thought himself quite equal to 
working the mine, no one was allowed to acquire claims 
Soon, however, he recognised the advantages of allowing others to 
assist him, and to peg out claims. 

The mine is situated amidst dolerite hills with an open flat 
piece of country to the south. The drainage water from these 
hills, flowed in a channel cut through the western portion of the 
mine, and it was in this that diamonds were first, found. The 
mine was covered on the western side by a thick deposit of black 
.alluvial soil, whilst the eastern portion lay on the slope of a hill 
and in parts had a slight covering of lime tufa. On opening the 
mine it was found that the greater part of it was buried beneath 
what is known as " floating shale," in which but few diamonds 
were found, and these only in small pockets of yellow ground con- 
tained in the shale. The shale dipped towards the eastern side 
of the mine, but was not one solid mass, containing in places 
several claims of a deep yellow looking ground, in which diamonds 
were found. The mine was more open and quite free of float 
shale to the west and south, and it was this portion which was 
worked with varying success. 

A peculiar feature in the Jagersfontein Mine 
was the varying nature of the diamondiferous material, in some 
parts the yellow ground was extremely sandy with hard nodules 


of the mineral cemented together by lime. In other parts a 
golden yellow ground occurred, which was so soft that without ex- 
erting much force a pick could be driven in to it up to the eye. 
Besides the two kinds mentioned there were several others, and as 
their nature varied, so did the yield in diamonds. It was no 
unusual thing in the yellow ground, for a digger to find 8 or 10 
carats in 40(Hoads one day, and on the next from the same 
amount uf stuff to recover from 50 to 80 carats. J he erratic 
yield of diamonds in the yellow ground was the cause ot many 
failures in the early development of this mine from 1867 to 1884.. 
Fresh capital was put into the mine and the blue ground worked. 
It was found that the yield from this was much more regular 
than from the yellow, and at the present day the rate is from 1 1 
to 13 carats per 100 loads, valued at from 37s. 6d. to 40s per 
carat The diamonds from this mine are superior to those ot any 
other mine in South Africa, a perfect gem is quite equal to a first- 
class Brazilian stone. Besides these first-water stones, fancy 
coloured ones are found, chief amongst which are brilliant choco- 
late coloured gems. The associated minerals are often large, and 
what are known as < burnt" garnets of a very large size are 
frequent whilst some of the largest diamonds from bouth Africa 
were obtained from this mine. It would almost appear as if 
one could anticipate finding large diamonds when the associated 
minerals are of abnormal size. 

The blue ground is easily pulverised, though like all other 
mines " hardbank " is encountered which will not decompose 
under'any condition. The diamond pipe is enclosed by columnar 
dolerite in a more or less decomposed state, but it stands well 
so that the digging operations are not often retarded by falls ot 
so-called " reef" into the mine. The associated minerals are 
similar to those of other mines, but the stone known as " Dutch 
Boart," which in reality is a topaz, is plentiful. 

Close to the Jagersfontein pipe, and north-west of it, a 
small pipe exists, known as " Rose's Mine," but it seems still 
doubtful if diamonds occur there in any quantity. One or two 
efforts were made to work it, but these were disastrous failures. 

Six or eight miles to the east of the Jagersfontein a pipe 
called the " Contatville " was opened in the early eighties, but 
it proved to be a complete " duffer," and contained no dia- 
monds. It was worked for a short time, and an ineffectual effort 
was made to create some enthusiasm over its discovery, but it 
was soon abandoned and is now almost forgotten. 

The mineral matter in the " Contatville " pipe is extremely 
micacious, and its general appearance indictes its poverty in the 
precious gems. 




lies about two miles from Bultfontein on the farm Vooraitzicht; 
It is similar to the other mines in general characteristics, but 
differs in having an intrusive dyke known as the Snake Rock 
running through it in a serpentine course. 

The mine was originally worked in patches, such as Schwab's 
Gully and others, and for a time it was almost abandoned. De 
Beers has yielded a large number of good stones and many of 
great value. 

It is named after the original owner of the farm Vooruitzicht 
(de Beer) upon which both it and the Kimberley Mine are situated. 

The yield per 100 loads is about 80 carats, and the value 
per carat 27/-. 


No mine is better known to the public than this valuable 
diamond pipe. 

It was discovered on the loth dav of July, 1871— -a red 
letter day in the history of the Cape Colony. The diamond mines 
previously discovered had, at this time, arrived at a critical stage 
of their existence, owing to the want of system in their develop- 

When Kimberley Mine was laid out into claims the Commis- 
sioner (Captain Finlayson) adopted -by the advice of the more 
intelligent and far seeing diggers- a S3 : stem of roadways which, 
ran from north to south through the mine, and which greatly 
facilitated its development. 

Each claimholder allowed 7 feet (J inches of his ground to. 
remain unworked, and by this means roadways 15 feet wide in- 
tersected the mining area and enabled the diggers to remeve the 
spoil from their claims to the sorting places. Gradually as the 
workings deepened these roadways were removed, and then the 
mineral was elevated to the sides of the great pit by means of 
windlasses, and later on by engine-power. Mounds and hillocks 
formed from the discarded material and sorted ground, grew in 
size and magnitude around the mine until the level landscape 
was transformed into one in which the white tents of the diggers 
were relieved by a number of grey coloured gravel hills. 

The surface of the ground which hid the Kimberley Mine 
from view presented no indication of the great wealth beneath. 
A slight rise on the sandy plain, a few kameel thorn trees, and 
some patches of limestone, were all that struck the eye in glanc- 
ing over the great expanse of barren territory in which it i& 
situated. A more uninteresting or dreary spot can scarcely be 


The late Mr. Fleetwood Rawstorne, of Colesberg, was the 
discoverer of this mine. He found a diamond after about a 
week's work, and the place was rushed by the diggers from the 
neighbouring mines. In an incredibly short space of time a 
mining camp with a population of 20,000 souls spread over the 
plain, and work proceeded with such vigor, as had never been 
previously witnessed on the Diamond Fields. Diamonds were 
found in great quantities in some parts of the mine, though other 
portions were exceedingly poor. In the centre and at the west 
-end diamonds were scarce, so much so, that a huge pillar of value- 
ess ground remained standing in the centre of the mine, until it- 
endangered the lives of the workmen in its vicinity. The richest 
spots were along the southern and the eastern poition, though the 
north side had some valuable patches. 

The sectional drawing, plate 3, fig. 1 , is copied from a larger 
■one found among the papers of the late Mr. G. W. Stow, F.G.S., 
who sketched it at the time when the miners had reached the 
blue ground. 

It represents the principal features of the mine. The cover- 
ing ot red sand lying upon white tufaceous limestone and suc- 
ceeded by the yellow, and finally the blue ground and the great 
-central mass of shale are clearly illustrated in this graphic sec- 

The tilt of the strata surrounding the mine is also shown. 


is of great extent and is poor in yield of diamonds, the richest 
ground producing only 5 carats per 1 00 loads, while the average 
from the claims now being worked, is barely 4 carats. This mine 
•affords another illustration of the patchiness of diamond pipes. 
Fully one-half of it being extremely poor, not yielding more than 
.2 carats per 100 loads. 

There is a great similarity between the mineral of this mine 
;and that contained in the Bultfontein pipe. Garnets and green- 
stone predominating, while carbon is less plentiful. A striking- 
peculiarity of both these mines is the apparent absence of all 
affinity between the carbon and garnets, where the former is 
plentiful the garnet is scarce and vice versa, but in no case does 
the number of diamonds appear to be affected by the abundance 
or scarcity of either the carbon and garnet. 


This takes its name from the Farm on which it is situated, 
and which lies at the north base of the Clocolan Mountain, in 
the District of Winburg and about 36 miles distant from that 

BBBBWiiili itn n i iiiiiiihi n nitfiiiniiiAiifiiii n iriumtrmii miij- aiiirrmi""r~r rnr ^Tr -~~ mimi ArfiiifmiTHtl — *" 


Plate 3, Pia. 1. 

after G. W. Stow. F. G. S. 





- 1 -+■< , 

«V* RED S *i|<- 

Horizontal ll n = 15QFt. 

V^rttc^i lin- Sort 

:±V r t- 


-i- 3 - r - -) - -x-[ •;• ' '.'i-r ■ ■▼ . •* a - 


\>^_v| »•• v— , — L 



/ £. 

.1 _ ( 

— r 

i. 1£ I 

jr.1~ — L ~ — 4 


Plate 3, Pig. 2. 





The existence of diamonds were determined about 25 years 
.-ago, a farmer, who named the mine " Viljoen's Rush," by which 
title it is still known to the farmers locally. 

This mine has had a most unfortunate career, owing princi- 
pally to incompetent management and obsolete machinery The 
diamonds found there are generally of good quality, and some 
have realised high prices, but the yield has fluctuated between 
6 carats and 20 carats per 100 loads. 

The most interesting features about this diamond mine are 
that it is situated in the highest sedimentary deposit on the 
great inland plateau, that it is 5,700 feet above sea level, and 
that there are evidences of its having been worked at some time 
previous to the discovery of diamonds in South Africa. Human 
remains and iron implements have been unearthed from a depth 
of about 25 feet, and the whole surface of the mine appears to 
have been turned over to an average depth of about 10 het 
Evidence collected from native sources points to the working of 
this mine by the Basutos to obtain the black glittering fragments 
•of carbon for the decoration of the Basuto ladies, but not to any 
mining for diamonds. At the present time a certain amount of 
carbon is sold annually to the Basutos, and they state that for 
about a century past they have been in the habit of obtaining 
their supplies of this article of female adornment from this spot 

The " carbons " and " garnets " obtained from the Monas- 
tery are phenomenally large, many of the former weighing ever 
one pound, and aggregations of the latter equal to about 6lbs. in 

The yellow and blue ground are not distinctly separated as 
in other mines, and there are large masses of "hard bank" in 
both the blue and yellow up to within a short distance of the 

In this instance again there was no outward sign of the 
existence of a diamond mine, the small shallow valley which runs 
parallel with the side of the Clocolan Mountain, was about the 
last place a prospector would look for a diamond mine : but the 
old workings visible as small mounds, but slightly elevated above 
the surface, yielded a few scattered carbons and garnets, and 
these gave the prospector (Viljoen) sufficient evidence to induce 
him to sink, with the result that diamond bearing soil was ex- 
posed to view. 

There is no mine in the country that has greater possibilities 
than this one. Hitherto the workings have been confined to one 
small isolated portion of the property, notwithstanding the fact 
that the diamondiferous ground is known to cover an area which 
would indicate that this is the largest pipe > yet discovered in South 


It is possible that the portion which has been operated upon 
is the most barren in the mine, and that there are rich spots as 
there are in all other mines. 

With vigorous and efficient management the Monastery 
Mine will some day take a leading part in the diamond output of 
the Orange Free State. Its yield has varied from 6 to 20 carats 
per 100 loads. Some of the diamonds found in this mine have 
been classed with the best Brazilian stones. 


This mine, from which so much was expected, but* which 
has not yet proved to be remunerative, is situated on the Farm 
Kaal Valley in the District of Ventersburg, and about 12 miles 
north-west from the Ventersburg Road Station of the Orange 
Free State line of railway. m 

The geological period in which this volcanic diamondiferous 
pipe appears on the surface is at the base of the Molteno beds, 
and consequently its orifiice is in a younger strata than that of 
Kimberley and Jagersfontein. 

Surrounding the mine there arc layers oi shale and sand- 
stone tilted on the north side to an angle of about 45 degrees as 
in the Kimberley mine. The mine is roughly oval in shape, and 
the longer axis of the oval lies in the direction north-east and 

south-west. . 

There was no indication of the existence ot a diamond mine 
on the surface of the ground, which was composed of chocolate- 
coloured soil. No limestone lay on the surface, neither was 
there an encircling ring of greenstone such as is generally sup- 
posed to indicate the presence of a pipe. 

The existence of the diamond was first suspected by the 
discovery of pieces of carbon, found in the earth that had been 
brought to the surface by an ant bear, and this was sufficient to 
encourage the prospectors to sink, with the result that a number 
of diamonds of good quality were discovered, and the mine was 
ultimately sold to the Robinson Diamond Mining Company. 

The yellow ground in this mine reached a depth of about 40 
feet, when blue ground, identical with that of the Kimberley 

Mine, was struck. 

The Robinson mineis not yet in the outputstage, the yield per 
load is unknown, but trial washings gave about 8 carats per 100 
loads. The diamonds were of superior quality. 


That diamondiferoiis pipes should exist so far distant from 
the centres which had been discovered in the^Bftrlf days of 



mining was generally disbelieved. The Robinson and Driekoppies 
Mines proved the extension of the area in which they might be 
sought for beyond its originally circumscribed limits, but the 
discovery of the Rietfontein Mine was a revelation t<> geologists 
as well as to miners. 

The discovery of this mine is another instance of the triumph 
of science over dogmatism. Blue ground could not possibly exist 
on the surface was an article of the diamond diggers creed, and 
therefore even experienced men overlooked the small patch of 
hard blue ground which cropped up through the Magaliesberg 

* quartzites, and ridiculed the idea that a diamond mine could be 
found therein. Kimberley and most of the better known mines 
were in the shales, and there was no shale at Rietfontein. 

The white lime was missing on the surface and the surround- 
ing ring was wanting, but the discoverers had recognised the true 
character of the mineral, and they remained unshaken in their 

• opinion, even when opposed by men of great experience. 

Finally, diamonds were found in quantity, and the 
results are most gratifying to Messrs. Draper and Frames, whose 
connection with this discovery was published in the local papers 
in September, 1897, to the owners, and to prospectors in general, 
to whose investigations a new field has been opened. 

Mr. Frames discovered the first diamond in washing the 
yellow ground, though the owner of the farm (Mr. van der Merwe) 
had picked up a small stone on the surface near the present mine 
a few days previously. 

Rietfontein Mine differs in many respects, as shown above, 
from the majority of diamond mines. The mineral in which the 
diamonds are found is not quite the same in appearance, though 
it is of similar composition to that of other mines. 

There is but a small quantity of yellow ground at Rietfon- 
tein, and " hard bank " is the form of the bulk of the mineral. 

There is little hope of softer mineral being reached, and 
greater probability that the density of the hard bank will increase. 
This will necessitate the employment of crushing machinery 
similar to that in use at some of the other mines. 

Rietfontein is probably the smallest diamondiferous pipe that 
has yet been discovered, but it also appears to be phenomenally 
rich, though the bulk of the diamonds found hitherto are not of 
very good quality, and a large proportion are fragmentary. 

Section 2, Plate 3 shows a section across the Rietfontein 
Aline from south to north at the time of its discovery. 


Chapter VI. 


REQUIRED.— By M. E. Frambs. 

When the prospector decides upon investigating a certain 
area, he should be provided with the ( necessary appliances and 
implements to conduct his operations in a systematic and work- 
manlike manner. In addition to the ordinary prospecting gear 
of picks, shovels, etc., he should have three sieves of different 
meshes to be used as will be pointed out later on. The one sieve 
should be coarse enough to allow a stone of the size of a very 
large pea to pass through, the next in size to allow stones as big 
as large pins heads to pass, whilst the third one should 
be so fine as to allow of the free passage of mud and sand only. 
These three sizes the prospector will find sufficient for all practi- 
cal purposes. Having procured his outfit the next question is 
which is the most likely locality to search for diamonds. Natur- 
ally the choice falls on'those districts where diamond pipes are 
known to exist, as such localities are more likely to contain other 
mines which may possibly be hidden from view. As described 
in chapter VII, the diamond pipes appear to occur 
traversing the country in more or less straight lines. 
Wherever streams run through a farm, or dry dongas 
and valleys occur, the gravels contained in them should 
be systematically searched. The modus- operandi to be followed 
by the investigator will greatly depend upon the physical feature 
of the country, and also the distance of water from the ground 
under investigation and other circumstances. Should a stream 
occur on the property the gravel along its bed and banks should 
be first put through the coarse-sized sieve, and can either be 
^S sieved direct into the next sized one, or on to a clear piece of 
^X ground. After two or three hundred weight of gravel has been 
sifted, the intermediate sized sieve should be used, and then the 
finer to shake out the dust and sand. After this has been 
accomplished the intermediate sieve should be about half filled 
with gravel or ground, and vigorously shaken with a circular mo- 
tion inthe water. The matter in which this is done is to sink the 
sieve beneath the surface of the water, holding it in the hands 
and spinning it round from left to right, then from right to left, 
until the gravel contained in it is free of mud. The sieve should 
be moved backwards and forwards, as if it had an 
axle passed through its centre and it were being tinsted in 
a half circle, first to the right then the left. Either water in 
the stream can be used to pan in, or tubs provided for the pur- 
pose. When the gravel is free of mud the sieve should be shaken 
steadily up and down, and when it is evenly distributed over the 


bottom, the up and down motion should gradually coase. On 
lifting the sieve from the water it should be held in a slanting posi- 
tion to allow the surplus water to run oft". An open space free of 
grass, should then be selected and the sieve turned completely over 
so as to expose the heavy gravel which has gravitated to the bottom 
of the sieve. This turning over of the sieve is not easily accom- 
plished and requires practice. The operator should let the sieve 
lightly rest in the palms of his hands and swing it away from his 
body, at the same time lifting it into such a position that it 
can readily be turned bottom upwards, after which it should be 
brought down smartly on the ground The prospector will find a 
kneeling position the most convenient to accomplish this feat. 
Whatever heavy material may exist will have gravitated to the 
bottom of the sieve by the process described above, and on its com- 
plete reversal will be found exposed to view on the surface. Each 
sieve thus dealt with must be carefully searched and its surface 
lightly scratched over. Pebbles which present any peculiarities 
should be taken and carefully inspected, crystals that appear to 
resemble the diamond should be submitted to the tests already 
mentioned in the earlier pages of this book. After the interme- 
diate ground has been treated the very fine sieve should be used, 
and this material should be more carefully dealt with than any 
of the coarser sizes. The prospector will do well 
to examine the proceeds of this seiving under a 
magnifying glass. Any carbons, garnets, or olivine 
crystals must be taken out and submitted to the mag- 
nifying glass so as to be certain of their genuineness. Should 
the prospector be fortnnate enough to find any of the minerals 
associated with the diamond in the stream, he should proceed 
further up along its course and try the gravels, 
sands, etc., and if these minerals are still en- 
countered, he should continue the operation until 
they cease to appear. He will now he certain that the mine 
is not far distant, and must be on one side or the other of the 
stream, or perhaps in its bed. He mnst now be 
careful and ascertain from which side of the stream these indica- 
tions of the diamond enter, after ascertaining which it is com- 
paratively easy to follow the trail until the mine is met with. 
Should the stream fail to show any indication of a diamond pipe 
in its vicinity, the dry courses cut by the rains, should be investi- 
gated, and some of the gravels carried to the nearest water and 
treated as has already been explained. After investigating all 
the hollows, valleys, streams, and dry dongas or water courses 
without encountering any encouraging results, the prospector 
should select certain areas and take these in rotation and examine 
them almost foot by foot. Some of the sand can be carried to 
the water and carefully panned in the finest sieve. The associ- 


&ted minerals must be carefully sought for in these fine sands, 
■as they are easily overlooked. 

The prospector need not be anxious to seek diamonds or the 
•associated mineials in the coarse gravel of the first sieve, as he is 
much more likely to be successful in the finer material. Diamonds 
•ot a large size are by no means so very plentiful, neither are large 
fragments of the associated minerals frequent, and much time is 
often lost in seeking these. The wash known to diamond miners 
as " fine sand," should receive the closest attention, and in our 
•experience has resulted in the greatest number of successes. In 
the event of failure in discovering the indications in the gravels 
and sands accumulated by the rush of water during the rainy 
season, the prospector must not be discouraged, as often the pipes 
are covered by superficial deposits such as sand, lime, etc., which 
tend to protect the mine from erasion in fiat countiy. It is 
always well for him to pay careful attention to soil thrown up by 
such burrowing animals as the ant bear, meercat, etc. These 
■creatures have led to the discovery, in one or two 
instances, of diamond pipes which placed the fortunate finder in 
possession of great wealth. Every change in the prevailing colon 1 
•of the soil should be noted, and the reason for such change care- 
fully investigated. The various colours given to the soil by the 
decomposition of different rocks cannot here be explained as it 
might confuse the prospector, and we shall therefore point out 
the most prominent features which might denote the existence of 
a mine. Perhaps the prospector on passing over the country 
notices one patch more or less circular in form, different in colour 
to the prevailing tint. The reason for this should be looked into 
and some of the sand panned at the nearest water to ascertain if 
any indications of the precious gems exist. Should nothing be 
found he can push his investigations further afield. On the other 
hand, if he finds the minerals he is in search of, he should at 
once sink a small shaft testing the gravel and 
sand every few feet as he sinks down. lie may, by 
this means, encounter the yellow ground, which has been des- 
cribed in a previous chapter Should such be the case, the pros- 
pector may now be certain of having hit upon a diamond pipe, and 
he is fully justified in spending a little capital in judiciously test- 
ing its richness in diamonds. This can be done by dry sifting three 
ot four loads of the stuff at the shaft, and then panning it in 
tubs provided for the purpose. By sifting out the 
sand by the dry process the water contained in the tubs will not 
be used up so soon, and grading the stuff to various sizes by the 
method already explained, will be found to be the quickest and 
mast convenient process of procedure. The tubs should be the 
two halvesof a hogshead, one being used to rough pan the ground 
in, whilst the other one should always be set aside with clean water 




to finish the panning, so as to thoroughly clean the wash, thereby 
minimising the chance of overlooking any diamonds. By this 
method it will be found that three or four tubs of water can be 
made to go a long way in case water is scarce or far distant. After 
manipulating the number of loads of ground mentioned, though 
perhaps no diamonds have been found, the prospector will be able 
to form some idea, by an inspection of the heavy deposit 
exposed on the overturned sieve full of ground, what prospect he 
has of rinding diamonds. Operations should not be confined to one 
locality, it is always an advantage to test the pipe in several 
places, for the sufficient reason that diamond mines are not of an 
even richness, some spots being much richer than others, whilst 
some are nearly barren. If diamonds are found those recovered 
from the surface soil should be kept separate from those actually 
taken from the vellow or blue ground. It should be noted 
that the first-mentioned souce is misleading, and in estimating 
the yield per 100 loads, the diamond matrix, or yellow ground, 
can alone supply the necessary data, as the surface soil probably 
contains many diamonds which have gravitated down, as the pipe 
has been slowly worn away under subrenal influences. If the 
results are encouraging, then a small rotary pan should be erected 
on a convenient spot near the mine, and systematic treatment ot 
the ground gone in for. It will not be necessary to give a des- 
cription of the machinery required, or how it is worked, for once 
having found a diamond mine, it is an easy task to obtain the 
services of a good practical man — and many of these are to be 
found — to direct and control the future operations. 

I trust the foregoing few hints to the seeker after wealth, 
together with the description of how to manipulate the sieves, 
will prove sufficiently clear and comprehensive to be of value to 
him I fully realise the difficulty of so exactly explaining the 
details of the modus operandi that it can be readily grasped by 
the unpractised person ; but I am convinced that any one, no 
matter how new to the process, will successfully handle the sieves 
if he will follow the instructions I have given. Our friend the 
"" new chum " need not be discouraged at failing to overturn the 
sieve without disturbing the gravitated contents, as success can 
only come with practice. If the prospector is only shown how 
gravitating the gravel and overturning the sieve is accomplished, 
he will be able to do it himself within a few hours, and within a 
week will he be an adept at it. 

All stones which resemble a diamond in any 
way should be put to one side for careful scrutiny 
later on, when some of the tests already given can be applied. It 
would be ^s well for the prospector who is unacquainted with the 
diamond to provide himself with a glazier's diamond. If the 
stone, suspected to be a diamond, is easily scratched then it is 



not the precious gem ; if scratched on great pressure being exerted 
it Ls probably one of the conundum family (sapphire) ; if marked 
without much difficulty, a topaz ; but if scratched with extreme 
difficulty or uot at all, it is a diamond. It would also be advis- 
able for the prospector to carry a few bits of garnets, carbon, 
olivine, etc., with him for the sake of comparison, and also to 
show to farmers and natives for the purpose of ascertaining if 
they know any locality where these minerals occur. It may happen 
that such a locality is known to the farmer or one of his cattle 
herdsmen and the prospector for a small remuneration may be led 
direct to the mine. A fragment of the yellow ground (oxidized 
mineral) and a piece of the " blue" will be found invaluable for 
the purpose of comparing with rocks in the field, and those not 
well up in the diamond matrix should provide themselves with 
tl^se and make themselves acquainted with their outward ap- 

The writer hopes that he has made himself sufficiently clear 
on points of vital importance to the prospector, and trusts lie has 
supplied the necessary data for practical use. An avoidance of 
technical terms has been observed, and the subjeGt dealt with 
in this chapter presented to the ordinary prospector in language 
which he will easily comprehend. 


Chapter VII. 

Before the announcement that the Monastery Mine was situ- 
ated in the Cave Sandstone or uppermost sedimentary bed of the 
Karoo Series, was made by Mr. Draper about a year ago, the fact 
that diamonds were not confined to the IiOwer Karo© or Kimberley 
Shales was not recognised. 

The position of the Monastery Mine in the geological 
sequence of the South African rocks, has practically increased the 
area wherein diamond bearing volcanic pipes may be found, to an 
extent, limited only by the shores of this continent. 

There is now no doubt but that the period wherein some of the 
diamond pipes reached the surface, was not earlier than the Cave 
Sandstone (Jurassic), and that those which now appear on the 
surface, surrounded by rocks of the Molteno, Beaufort, Ecca, or 
Magaliesberg periods, have either been lowered to their present 
geological position by denudation or they came to the surface 
since the country had rece'nvi] a great portii/n of its present 
surface outlines. 

It will be reasonable to assume that the epoch of diamond 
pipes was confined to one period of time, and that all the mines 
are of one age chronologically. If this is not the case, then the 
alternative of a number of successive eruptions, similar in operation 
and containing identical mineral ogical features, but with great 
intervening lapses of time, must be accounted for. 

Then again, there appears to be a certain regularity of 
occurrence, along distinct lines which these eruptions favoured, 
and in the course of which diamonds are found to-day. One of 
these runs apparently in a north-easterly direction intersecting 
the Jagersfontein, Robinson, Driekoppes, and Rietfontein (Pre- 
toria) Mines, and it is interesting to note that if this line is 
extended south-westward into the Cape Colony, it intersects the 
pipe which was worked years ago on the farm Klein Andriesfon- 
tein, near Hanover, and that the diamond finds near the 
Inlandsche Zee, and on the Keller property, in the Orange Free 
State, lie along what was probably this line of fissure or fault. 
If this line is extended north-eastward \\t passes slightly to the 
eastward of the Springl>ok Flats, where diamonds are reported 
to have been found, and terminates in the Klein Letaba > 
from whence diamonds have been obtained. 

It is also interesting to note that the " pipe amygdaloid ' of 
the Drakensberg, which possibly indicates another line ot " fissure 
irruption " runs in the same direction as the line of diamond mines 
and parallel with it, and that the principal faults in the Wit- 
watersrand, Magaliesberg, and Gatsrand have a somewhat similar 
direction of strike. 




When one critically examines a diamond pipe it is difficult 
to believe that it represents a small hole, which has been punc- 
tured in the earth's crust by some force acting from within. It 
is more natural to assume that a fault, or fracture occurred, 
and that the diamond pipes are simply bulges or irregu- 
larities in the line of fault, and that these served as passages 
through which the molten or plastic mineral, carrying the dia- 
monds, found its way to the surface. 

Dr. Molengraaff some years ago published this theory in a 
little work on South African Geology, entitled "' Schets van de 
Bodemgesteldheid van de Zuid Afrikaansche Republiek, etc.," 
door G. A. F. Molengraatt, and published by E. J. Brill, Leiden, 

On page41 of theabove-mentioned pamphlet there is adiagram, 
illustrating the direction of several of these Hues of fracture, and 
though this is correct so far as the knowledge of diamond mines at 
the time the book was published is concerned, recent discoveries, 
coupled with the previously known facts, show that there is great 
probability that the principal line of fissure runs in the direction 
described in these pages, and that it is along this line that the 
most important discoveries of diamonds will be made. Prospec- 
tors are therefore advised to search in the direction of and along 
the line which is indicated in the map attached. 

Naturally a fissure or fault would not adhere to a perfectly 
straight line, there would be a certain amount of irregularity in its 
course which must be taken into consideration ; but the principal 
matter to be observed is general direction, and that can be best 
ascertained by examining a larger map of South Africa, and notic- 
ing the direction in which the line of diamond pipes, previously 
mentioned, takes and then either extending this at either end or 
searching in the country which lies between the already dis- 
covered mines. 

We would, however, caution those who are new to the busi- 
ness that there are many blanks to a prize in diamond prospect- 
ing. Every volcanic pipe is not a payable diamond mine, and 
many are perfect " duffers." Nor are the garnets, carbons and 
greenstones infall ble in their indication of a diamond mine. 
Though the diamondljbas never been discovered except in their 
company, they haw Seen found in abundance without the diamond. 


mt**tm**mt+m mm Hm* J il t *m i* ■ * 






J 5° 

or ° 




3C <^ I & 7i/ cl r 





Hiif/lish MHcc 







DIAMOND PIPES : 1. Rietfontein (Pretoria). 2. Driekoppies. 3. Robinson. 4. Keller? 5. Jagersfontein. 6. Klein Andriesfontein 

7. Kimberley Group. 8. Monastery. 9.\Carmel. 
Note. — The Arrow points in the direction of the Main Fracture described on page 35. . . 

1 1 i ■ r : . -I.!..,- , ., -r. , 





In searching for a diamond mine don't look for a circle of 
dolerite or igneous rock. No mine that has yet been discovered 
had such an enclosing circle. Kimberley was utterly devoid of 
such an occurrence. 

There was in fact nothing on the surface to denote the 
presence of the richest diamond mine that has yet been dis- 
covered. No kopje or hillock nor circular enclosure of igneous 
rock, nothing but a rise of a few feet in the plain, a few chunks 
of white limestone peeping through the red sand, and several 
kameel thorn tree scattered about the surface. 

Limestone tufa is no indication of a diamond mine. This 
feature was certainly associated with the Kimberley and Wessel- 
ton Mines, but was absent from most of the others and utterly 
wanting at Rietfontein. 

Search diligently in the stuff brought to the surface by the 
burrowing animals. These are good prospectors, and their work 
costs nothing. They give a general idea of what is under the 
surface for a distance of several feet. % m 

If a patch of different coloured soil is noticeable, and if this 
is in a roughly circular shape, it will be well to examine it care- 
fully. . . ,. 

Though not giving this as a hard and fast rule, most^ dia- 
mond mines have^a red earthy covering due to the decomposition 
of the diamond bearing mineral itself probably. This was parti- 
cularly in evidence on the Rietfontein Mine, where a small pateh 
of bright red soil was surrounded by an encircling line of white 
or grey earth. The red patch indicated the extent of the mine 

to within a few feet. . . 

Don't be afraid to search for a diamond mine anywhere in 
South Africa (at any rate so far north as the Limpopo). There is 
no limit to the area in which it may be found, either in geological 
position or in the altitude above sea level. 

Notice whether a certain number of mines appear to follow 
a distinct direction, and if so proceed to examine the inter- 
vening country or extend the prospecting operations in either 
direction beyond the outside mines. A line of fissure may exist 
in that direction^ and possibly certain swellings or pipes exist 
which may contain diamonds. . 

The majority of diamond mines discovered up to date have 
been richer on the surface than in depth : Kimberley I>u ioiti s 
Pan, and Bultfontein are notable examples of this feature which, 
in all probability, is due to a process of weathering, to which the 
mineral in the pipes has been subjected. 





The diamond, being practically indestructible, would survive 
for the most lengthy period, whereas the accessory minerals, and 
especially the matrix, would disintegrate, and crumble into pow- 
<ler, which would be removed from its original home, by the sum- 
mer rains and winter winds. 

The upper portions of the diamond pipes really contain the 
■concentrates produced by surface weathering, hence their richoes* 
in the diamond, and its more durable companions. 









ELECTED JULY 30th, 1870. 


Alluvial Claims. 

1st,— Every man to be allowed 20 feet square. No party 
•claims to exceed six in number, whose sole claim must be taken 
in conjunction. 

2nd.— The boundary of each claim to be distinctly marked, 
•and such marks at all times to be kept free from rubbish. 

8rd. — All claims to have free access at all times for the 
removal of wash dirt over any other claims that may be at work. 

4th. — No claims to be allowed to throw their rubbish upon 
their neighbour's claim without permission. 

oth. — Should any dispute arise between two or more parties 
respecting their claim, such dispute shall be settled by the arbi- 
tration of four assessors appointed by the partievS in dispute, and 
a referee to be called in by the assessors, if necessary, whose den- 
ion shall be final. 




6 th.— Should any party or parties mark oft" more ground than 
allowed by these rules, any other person shall have the option of 
taking the surplus ground from any side of such claim he may 
L hink proper. 

River Claims, 

7th. — Each man to be allowed fifty feet frontage along 
the bed of the river, the same to be distinctly marked at low 
water mark. 

Prospecting Claims. 

8th. — Any person discovering a new run or patch of dia- 
monds shall, upon reporting the same to a committee appointed 
be entitled to four ordinary claims, and such report to be posted 
up in a conspicuous place on the present diggings, stating the 
locality ; and should he fail in reporting, and another person 
finds payable ground in the same locality, the first person report- 
ing shall be entitled to the prospecting claim. 

9th. — No party shall be allowed to remain absent from his 
claim more than three successive working days, unless in case of 
sickness, work in conjunction with his claim as washing, etc., or 
pressing business, when a notice must be posted up on his claim 
stating the time of his absence, after which time the claim shall 
be considered as abandoned. 

10th. — No man shall be allowed more than one claim at the 

same time. 

11th.— Any person against whom it shall be proved as having 
picked up a diamond upon a claim belonging to another and not 
restoring it to the owner of such claim immediately, shall be con- 
sidered as a thief and expelled the diggings. 

12th. — No heap of dirt upon any abandoned claim shall be 
considered as private property, unless it can be shown to a 
committee that some accident, such as rain, breakage of wagon, 
etc., has prevented the washing or sieving of such heap of dirt. 

13th. — That no party or parties shall be allowed more than 
\\\e niggers to work their claim. 

P. D. J. Vanderbyl, Chairman. 






4 Diamond Grains 
150 Carats 

... ... ... i v^aTctx 

... 1 oz Troy 

A diamond grain is equal to 0.8 of a troy grain. 



Carbonado or Black 

Boart ... 

Ruby ... 
Topaz ... 
Zircon ... 
Garnet ... 
Spinel ... 


SP. OR. 

3.0 to 3.4 



9 3.9 to 4.1 

9 3.9 to 4.1 

8 3.4 to 3.6 

7.5 4.0 to 4.7 

6.5 to 7.5 3.15 to 4.3 Red. 

8 3.5 Red. 



Grey, lead colour. 

White, colourless 


Straw, white. 
Brownish yellow. 

These will sink in the gravity Solution of sp. gr. of 3.17. 

Beryl ... 
Quartz ... 
Agate ... 
Onyx ... 

Opal ... 

These will float on the gravity Solution as abore. 


SP. GR. 



2.6 to 2.7 

Greenish yellow. 


2.5 to 2.7 


7 to 7.5 

2.9 to 3.3 

Black, rose. 


2.5 to 2.8 



2.5 to 2.8 

White, transparent. 


2.5 to 2 8 



2.5 to 2.8 

White on darker 



Light blue. 




5. to 0. 

1.9 to 2 



Telegraphic Address . 

Mareing and Neav3's, 1395, 
and ABC Codes used. 

H. f. C. KEYMER, 

Consulting Engineer, 


itOR MACHINERY of the latest and most complete character 
jj for treating Diamond if erous Soil, Rocks, etc., H. J. C. 
Kkymer represents the best Manufacturer^, and, with the largest 
experience in such manufactures, will be pleased to advise upon 
the Machinery suitable, prepare Plans, and carry out the erection 
of the same, if required. 

Also Agent for (til up-to-date 

Steam, Electrical, and Water-power Plants, 

And will be pleased to Quote for any of the above on 


TAYLOR and CO., chemists & druggists, 


Always keep on hand 


$Ub $pp<xrafu6 requisite for QsB<x$in$ 
Ores. (UXtncrafB. etc. 

So'ution for taking the Specific Gravity 

A Speciality. 

Cases of Chemicals and Test Apparatus . . 
. . . Prepared to Order for Prospectors. 





Engines (Driving and Winding), 

Boilers, Diamond Drills, 

Pumps, Rails, Piping, Trucks, Tents, 

Jumper Drills, Winches, Hose, 

Bucket Elevators, 
* J ' Engine and Boiler Fittings, 

Windlasses, etc., etc. 



t # 


• t 




j"oiH:-A_isr:isr:E sbtjrg-. 

P.O. Box 1945. 

P.O Box 1945. 









i ;: