Skip to main content

Full text of "Diamonds"

See other formats


Google 



This is a digital copy of a book that was preserved for generations on library shelves before it was carefully scanned by Google as part of a project 

to make the world's books discoverable online. 

It has survived long enough for the copyright to expire and the book to enter the public domain. A public domain book is one that was never subject 

to copyright or whose legal copyright term has expired. Whether a book is in the public domain may vary country to country. Public domain books 

are our gateways to the past, representing a wealth of history, culture and knowledge that's often difficult to discover. 

Marks, notations and other maiginalia present in the original volume will appear in this file - a reminder of this book's long journey from the 

publisher to a library and finally to you. 

Usage guidelines 

Google is proud to partner with libraries to digitize public domain materials and make them widely accessible. Public domain books belong to the 
public and we are merely their custodians. Nevertheless, this work is expensive, so in order to keep providing tliis resource, we liave taken steps to 
prevent abuse by commercial parties, including placing technical restrictions on automated querying. 
We also ask that you: 

+ Make non-commercial use of the files We designed Google Book Search for use by individuals, and we request that you use these files for 
personal, non-commercial purposes. 

+ Refrain fivm automated querying Do not send automated queries of any sort to Google's system: If you are conducting research on machine 
translation, optical character recognition or other areas where access to a large amount of text is helpful, please contact us. We encourage the 
use of public domain materials for these purposes and may be able to help. 

+ Maintain attributionTht GoogXt "watermark" you see on each file is essential for in forming people about this project and helping them find 
additional materials through Google Book Search. Please do not remove it. 

+ Keep it legal Whatever your use, remember that you are responsible for ensuring that what you are doing is legal. Do not assume that just 
because we believe a book is in the public domain for users in the United States, that the work is also in the public domain for users in other 
countries. Whether a book is still in copyright varies from country to country, and we can't offer guidance on whether any specific use of 
any specific book is allowed. Please do not assume that a book's appearance in Google Book Search means it can be used in any manner 
anywhere in the world. Copyright infringement liabili^ can be quite severe. 

About Google Book Search 

Google's mission is to organize the world's information and to make it universally accessible and useful. Google Book Search helps readers 
discover the world's books while helping authors and publishers reach new audiences. You can search through the full text of this book on the web 

at |http: //books .google .com/I 



9jar-,"( 









/ 



^^ 



/T 



♦ .-■*' "* « - . • •. V ■ 



« 4i> 




■I' 

.1 

• -♦ ■ 



DIAMONDS. 



BY WILLIAM POLE, 

ITELLOW OF THE GEOLOGICAL SOCIETr, ETC. ETC. 



\ 

3 



ExtratUdfrom Macmillan's Magazine /or January, 1861 



|HE IMPERIAL STATE CROWN AND ITS JEWELS 



WITH A NOTE ON 



BY 



PEOFESSOR J. TENNANT, F.G.S. Etc. 

Reprivi^lfrm, the Thansactions or the London aito Middlesex Arch^olooical 

Society, Volume I. 



■ f. 



LONDON:— 1861. 

[Printed for Private Circulation.'] 



) 7 :~vi; 






DIAMONDS. 



BT WILLIAM POLE, 9.O.B. 



Who does not love diamonds ? Where 
is there a mind in which the bare men- 
tion of them does not excite a pleasant 
emotion 9 Is there any one of rank too 
exalted to care for sudi baubles 1 The 
highest potentates of the earth esteem 
them as their choicest treasures, and 
kingdoms have been' at war ibr their 
possession ; while there is none so low 
or so poor as to be unable to find plea- 
sure in the admiration of their splendour* 
Shall we turn to the domain of intellect, 
where surely the gewgaws of ornament 
should be lightly esteemed) The dia- 
mond offers to the philosopher one of 
the most recondite and subtle problems 
that have ever engaged the human 
mind; while the merest tyro in science 
may find in it the most instructive 
topics of study. Shall we look at it in 
an artistic point of viewi The dia- 
mond is one of the most beautiful things 
in nature. "No painter, were he ten 
times a Turner, could do justice to its 
effulgence 3 no poet, were he ten times a 
Shakspeare, oould put its lustre into 
words. Zi^Ju was the fii'st and feiirest 
gift of heaven to man ; the diamond is 
fairer than light itself; it w light, only 
seven times beautified and refined 
For one half the human race diamonds 
are delirium*— the true eyes of the basi- 
lisk : tiieir power over l^e sex we dare 
not do more than hint at, and the 
woman who would profess herself in- 
different to their fascination simply 
belies her feminine nature. One of 
the most extraordinary romances in 
the history of the world was all about 



a diamond necklace and who would 
venture to number the true romances 
occurring every year of our lives 
in which diamonds take part) As 
regards the less decorative sex, the 
diamond forms altogether an exception 
to the usual idea of the propriety of 
ornament A man who bedizens him- 
self with gold or jewels ^in general is 
rightly pronounced an empty fop ; but 
the wearing of a fine diamond will only 
mark its possessor as having a superior 
taste for what is most admirable and 
beautiful among the productions of 
natura The minerals we call gems, 
jewels, " precious*' stones, par excellence^ 
are the most noble objects of inorganic 
creation ; and the diamond is the queen 
of them all. 

Let us then have a chat about dia- 
monds, which will interest everybody. 

The localities where diamonds have 
hitherto been found, are Central India, 
Sumatra, Borneo, the XTral mountains, 
Australia, some parts of Korth America, 
and the Brazils ; but the first and last 
sources only have been of any great 
extent Down to a comparatively late 
period the continent of India was the 
only district of any importance, whence 
diamonds were obtained. The principal 
regions producing them were the high 
valleys of the Fennar near Cuddapsui, 
and of the Xistna near EUora (and not 
fax from the hill fort of Grolconda, the 
name usually associated with these 
ancient and rich mines), as also a rude, 
little known, mountainous district, con- 
taining the sources of Kerbudda and 
• a2 



Dia/monds, 



Sone ; and a range of hills in Biindel- 
kund, between the latter river and the 
Sonar. The produce of these mines was 
enormous, both in regard to number and 
size. One of the Mohammedan Em- 
perors, who died at the end of the 
twelfth century, after a long reign of 
plunder, is stated to have amassed in 
his treasury 4001bs. weight of diamonds 
alone. In later times, however, the pro- 
duce from 'this part of the world has 
gradually fallen off, and is now entirely 
superseded by the more recently dis- 
covered mines of the Brazils. 

The existence of these was revealed 
to the eastern world by an accident in 
the year 1727. A Portuguese of the 
name of Bernardino Fonseca Lobo, when 
at the gold mines of Minas Geraes, saw 
the miners using, as card counters, small 
stones which they said were found in 
the gold washings, and which he, having 
seen similar ones in the East Indies, con- 
jectured to be rough diamonds. He 
brought a quantity to Lisbon, where his 
suspicion was confirmed, and public at^ 
tention was at once drawn to the rich 
discovery. The European dealers, who 
had hitherto obtained their stones from 
India, fearing that they would be depre- 
ciated in vfidue, spread the report that 
the pretended Brazilian diamonds had 
been surreptitiously sent from Groa to 
South America; but the Portuguese 
soon demonstrated their authenticity, 
and turned the tables upon the meir^ 
chants, by actually sending them to 
Goa, and selling them in India as native 
produce. The discovery once made, 
the sources of supply were soon found, 
and worked extensively, and proved 
very productive. The stones abound 
more or less on the great north and 
south ranges of the country between 13 
and 21^ south latitude; but the prin- 
cipal working, so long known as the 
diamond district, and in which the 
town of Diamantina lies, is a high, 
mountainous, and sterile tract of country, 
situated between the heads of the rivers 
Doce, Arassuahy, Jequetinhoiiha^ and 
the great river of San Francisco. The 
ancient province of Bahia has also mQre 
lately become one of the principal 



sources. In 1843 a mulatto miner, who 
had gone alone into the interior to search. 
fpr new washings, was working up to 
his ankles in water, in the bed of a 
stream at Sincora, in this province, 
when, dropping the end of his cro-w- 
bar, to rest himself, on the ground 
below, he was somewhat surprised at 
hearing it sound hollow. He repeated 
the blow a second and a third time, 
when the bar fell through. He put liis 
hand into the hole, and pulled out a 
handful of diamonds. Elated with his 
discovery he returned home, and offered 
the stones for sale to some of the parties 
with whom he had been formerly en- 
gaged. As the diamonds were of a 
different quality and shape from any they 
had seen before, they taxed him with 
having discovered a new mine, which 
for some time he strongly denied ; but, 
on being thrown into prison on the 
charge of stealing the diamonds, he con- 
fessed his discovery, and, on promise of 
making it known, was released. . The 
hole he had broken into produced alone 
ten pounds of superior stones, worth 
probably more than 100,000?. in their 
rough state ; and, on the neighbourhood 
being searched, the produce was so 
abundant, that six or eight months 
afterwards, from 10,000 to 15,000 people 
had collected on the spot, and in the 
first two years it is supposed nearly 
600,000 carats were extracted, to the 
value of above half a million of money : 
an influx into the market, which for a 
time very seriously depreciated the 
value. This circumstance, however, 
combined with the increased difficulty 
of extraction, the imhealthiness of the 
climate, and the high prices of provi- 
visions, soon checked the production, 
and brought matters again to a more 
normal state. Since this time another 
new mine has been discovered, pro- 
ducing good stones, and the diamond- 
bearing district is so extensive as to 
remove any fear of speedy exhaustion. 

The total production of diamonds from 
the Brazilian mines has been estimated 
up to the year 1850 at upwards of 
10,000,000 carats, or above two tons ; 
and valued at 16>000,000?. sterling. At 



Diamortds, 



some seasons the general richness of the 
ground has been marvellous; after a 
^P ^' rain the children would seek gold in the 
gutters, and often find large quantities ; 
diamonds have been found in the vege- 
table roots in the gardeiis, and in stones 
carelessly throwji about the road ; even 
the fowls would pick up diamonds. 

The prevailing rocks in the diamond 
districts are the same as the usual au- 
riferous strata, i,e, chiefly varieties of 
metamorphic mica schist, occasionally 
intersected with irregular quartz veins. 
The matrix in which the stones actually 
lie is a mineral called Itacolumite, from 
the mountain Itacolumi, in Brazil, where 
it was first discovered. It is a silicious 
conglomerate, cemented together with 
ferruginous matter, and appears to have 
undergone plutonic action. The dia- 
monds lie often imbedded in flaky por- 
tions of this material, like the well-known 
specimens of garnets in mica schist In 
some parts of the Brazils the stones have 
been sought to some small extent by 
working the original vein in the rocks ; 
but this has been troublesome and ex- 
pensive, and recourse is had in preference 
to the alluvial beds of streams and rivers, 
where the diamonds are brought down 
with the detritus from the hills above. 
These water-courses have been always 
considered the most productive in fine 
stones, as well as the most profitable in 
working. Gold dust, and some few other 
stones, are found along with the diamonds, 
but the ktter always form the principal 
object. The colour, crystallization, and 
quality of the stones, are generally 
much alike in the same district, but 
the size varies considerably, large and 
small being found all together. The 
great majority of stones ^und are of 
small size ; it is said that only about 
pne in ten thousand wiU exceed, when 
cut, ten camts in weight, and hence the 
disproportionate increase in value of large, 
sized stones. 

The Brazilian mines were formerly 
worked by government ; but bad manage- 
ment and the extensive system of rob- 
beries practised by all classes concerned, 
caused this plain, to fail and they are 
now formed out to private individuals, 



who carry on the wop kingfe at their own 
risk and profit Slave labour is stiLI 
employed, but all possible precautions 
are taken to prevent dishonesty. Thefts 
are severely punished, and rewards are 
oflered for integrity and success in work- 
ing. The slave who finds a diamond of 
17^ carats, is crowned with a wreath of 
flowers, and led in procession to the 
overseer, who gives him his freedom, 
accompanied with a new suit of clothes, 
and permission to work for his own 
profit; minor rewards are given fop 
smaller stones. 

The method of working for the stones 
is very simple. The streams are diverted, 
and the water exhausted as much as pos- 
sible from the beds by pumping ; the 
gravel and alluvial soil are then exca- 
vated and washed in troughs by means 
of currents of water ; the ea^y particles 
being fijst carried away, the remaining 
gravel is carefully searched for diamonds, 
which are easily recognised by those 
acquainted with them. The process of 
working is carried on as long as the dry 
weather lasts, namely, firom April to the 
middle of October, all vestiges of the 
diggings being soon destroyed by the 
succeeding heavy rains. All the work 
is done by hand, no machinery having 
been hitherto found to answer. 

Diamonds are usually found in crys- 
talline forms — ^principaUy six, eight, and 
twelve sided, called by mineralogists the 
cube, the octohedron, and the rhombic 
dodecahedron; the two latter forms being 
the most common. In the rough state 





Octohedron. 



Dodecahedron, 



the stones are semi-transparent, but 
quite devoid of brilliancy ; much resem- 
bling small pieces of gum-arabic. Ex- 
perienced persons can, however, in this 
stage, easily judge of what their future 
quality and value will be. 

•The rough diamonds are transmitted 
by the owner to the coasts and shipped. 



' 



Diamonds, 



generally, at Rio ttaneiro, to meKhants 
in Europe ; by far the greater part coming 
to London. These merchants again sell 
them to other houses, whose business it 
is to get them cut, and so to giye them 
the precious brilliancy which is their 
principal characteristic. 

The art of cutting diamonds into a 
Tegular shape is of comparatively modem 
invention ; they were long worn in their 
natural state, or only cleaned and pol- 
ished. It appears, during the fourteenth 
century, some attempts were made to cut 
them into regular forms, but without 
any view to the improvemeht of their 
iMilliancy j and it was only in the year 
1456, that a certain Louis van Berquen, 
of Bruges, discovered the principle of 
cutting /aegto upon them, on which their 
lustre, as now known, so much depends. 
Cardinal Mazarin, about 1650, invented 
the perfect form of the brilliant, and 
had twelve large diamonds of the IVench 
crown cut into this shape, which has 
ever since been acknowledged the best 
possible for exhibiting the beautiful op- 
tical properties of the stone. 

Diamond cutting, in the present day, 
is almost exclusively done by Jews at 
Amsterdam, where large diamond mills 
have been established ; and it is calcu- 
lated that 10,000 eut of the 28,000 
persons of the Jewish persuasion living 
in that city are dependent directly or 
indirectly on this branch of industry.^ 
One of the largest establishments is that 
of Messrs. Coster, in the Zwanenburg 
Straat, who use steam-power to drive 
their maclunes, and employ from 200 to 
300 hands. 

The process of cutting the diamonds 
is as follows : — ^The rough stone is first 
given into the hands of an experienced 
workman, who examines its natural form, 
and determines what general shape and 
size it can most advantageously be made 
to asaume. Having settled this in regard 
to two diamondSi he beds each of them 

1 The wrHer had lately the advantage of 
Tislting the Amsterdam diax&ond woria, along 
with Fvofeflsor Tenn^t, one of our beat 
English connoissetzra in preeioua atones, and 
to whose kindness- he is indebted for much 
of the information in the present paper See 
also Kluge'a ^ Haadbuch der Edelfiieinkunde/* 



in a mass of cement placed at ihie end oi 
a piece of wood of a convenient size 
for handling; and then proceeds to rub 
the two stones one against the other, on 
the principle of "diamond cut diamond," 
changing from time, to time the parta 
acted on, and so bringing both stones 
gradually into the form he desires. Tlie 
mutual abrasion of the two stones pro- 
duces diamond powder, which is care* 
folly preserved for the subsequent ope^ 
rations. When the diamond has received 
its general shape^ it is sent into the mill 
to be finished, by cutting upon it the 
numerous small angular *^ facets," aa 
they are termed, which make up the 
surface. This is done by exposing the 
stone to the action of diamond powder 
on a steel plate revolving with great ve- 
locity — an operation perfectiy analogous 
to that of glass cutting, or the ordinary 
well-known lapidary's wheel. The cutting 
plates are usually about ten or twelve in- 
ches in diameter ] they are placed horizon- 
tally with their spindles vertical, and 
are made to revolve about thirty or forty 
timessin a second; the part acting on 
the diamond travelling over the facet 
at the rate of about a mile in a minute. 
Diamond powder, of extreme fineness, 
mixed with the best olive oil, is placed 
with a feather upon the upper table of 
the wheel, and the apparatus is then 
ready for action on the diamond. The 
stone is embedded in a mass of soft 
metal, an amalgam of lead and tin, easily 
fusible, and yet hard enough to retain 
the stone finnly in its position \ this is 
fixed in a moveable handle, which is 
again attached to a small frame. The 
workman, having first heated the metal 
to a soft state, beds the diamond iu it in 
the required position, and fixes it there 
by plungiDg into water ; the frame is 
then placed to project over the wheel, 
and the diamond, being downwards, 
comes in contact with its upper surfsEice^ 
on which the diamond powder is placed ; 
weights are then applied, and the result 
of the Motion, at the immense velocity, 
is to cut a facet upon the stone in a very 
short space of time. When one of these 
is finished, the workman softens the 
metal, extracts the stone, and replaces it 



Diamonds, 



ced 



,851 



in the proper position for making another 
facet ; and here comes into play a very 
remarkahle feature of the operation, 
namely, the aocuraoy of judgment which 
skill and experience give in arranging 
the faces of the stone. It is ohvious 
that, in any many-sided solid body whose 
shape is to have any pretensions to 
regularity or symmetry, the different 
faces must not only all stand in certain 
de&iite angular positions in regard to 
each other, hut must all hear a certain 
size in relation to the magnitude and 
form of the whole. Further, any one 
acquainted with geometry will know, 
that for a solid figure of fifty or sixty 
sides, the determination of these angles 
and sur&ceS) by any theoretical rule, 
would be a matter of great difficulty ; 
while the attempt to make such a figure 
practically, by any one unskilled in the 
operation, would onlyleeul to continual 
trial— and errois-attempts, which, even 
if the thing were ever properly done at 
all, would waste a large portion in the 
operation, and consequently much dimi- 
nish the ultimate avaUable size. Any one 
who will try, for example, to cut a turnip 
or a potato, by his eye and hand only, 
into a regular octohedron, or solid figure 
of eight equal and similar sides, will at 
once appreciate the difficulty* Yet the 
diamond-cutter has to do a much more 
difficult problem, namely, to give about 
sixty symmetrical and regular &ces to 
stones sometimes only about an eighth of 
an inch diameter ; without any mechan. 
ical aids whatever to his judgment ; and 
yet producing, without a particle of un- 
necessary waste, the very largest stone 
geometrically possible out of the rough 
body. This of course can only be the 
result of great skill and long experience. 
Having made one facet, he judges by 
his eye the exact angle at which the 
stone must be placed to eut the new one, 
and the exact depth to which the grinding 
for the latter must be carried ; and so 
accurately is this done, that it is very 
seldom a good workman ever has to 
revert to a facet for correction, after he 
has once passed it over. The stone is 
so fixed la the metal as to leave other 
facets visible for constant comparison 



with the one under progress ; and the 
handle is capable, by a sort of universal 
joint, of adjustment to any nicety for the 
position of the stone in touching the 
wheel. There is no further division of 
labour than between the rough cutter 
and the flmsheis-the latter taking the 
stone from the former in its roughed-out 
state, and returning it to the proprietor 
in the shape of the perfect finished bril- 
liant ready for sale. The last touches to 
the facets consist of polishing, or giving 
to them the peculiar diamond lustre j 
but this is in no wise difibrent from the 
grinding, except in being done with 
more care. The man can at any time 
adjust the Weight or force With which 
the stone is pressed upon the wheeL or 
he can remove it entirely, and substi- 
tute the gentle pressure of his hand ; 
and he can also modify the veloity of 
the grinding action ; for, although the 
wheel itself is kept at a constant nxmiber 
of revolutions per minute, he can place 
the stone nearer to, or farther ftom the 
axis, as he likes, which will of course 
give a less or greater effective velocity^ 
according to tibie radius of the acting 
circle* 

The diamond powder, of which a large 
quantity is used, is obtained partly from 
the first process, of rough-cutting the 
stones ; partly from diamonds of a quality 
not good enough to cut for sale, which 
are broken up for the purpose ; and partly 
from the newly discovered substance, 
" carbonado," which is hard enough for 
this use, although of a somewhat coarse 
quality. The powder is carefaUy sifted 
cleaned from dirt and extraneous mat' 
ters, and, when about to be used, is mixed 
with the finest vegetable oiL 

The workmen are all Jews, and are 
regularly educated to the trade. They 
are paid by piece-work. Formerly, they 
did their work at their own houses, their 
wheels being turned by manual power ; 
but it is now found more advantageous 
for the large proprietors to provide 
workshops of their own furnished with 
steam power, for the use of which the 
men pay out of their earnings Some of 
the more skilful and industrious men 
realise considerable incomes* There is, 



8 



DiaTrwnda, 



of coursei always temptation to dis- 
honesty, from the great value which is 
compressed into so small a space ; but all 
possible precautions are taken, and the 
character of the men is made of so high 
weight in all the transactions with them, 
that losses very seldom occur. 

The form into which a diamond is 
cut has great influence on its beauty and 
flre. The two most common are what 
are called the "brilliant," and the 
"rose" or "rosette." The latter, so 
named firom its similarity to an un- 
opened rosebud, was one of the earliest 
forms in use, and is applied generally 
to the cheaper kinds of stones. It is a 
sort of pyramid, with a flat base, and 
inclined facets, terminating upwards in 
a pointed apex. The flat base is im- 
bedded in the setting ; and, therefore, in 
the rose diamond, the whole of the 
stone appecurs projecting above. 

The brilliant is the more valuable 
form j it may be considered as formed 
' of two pyramids, connected together at 
their bases, with the apex of each 
truncated or cut off, and the sides 
worked into facets, as in the case of the 
rose. The stone is held in the setting 
at the broadest part, or junction of the 
pyramids ; one pyramid projects up- 
wards in sight, the other is hidden 
below, so that only half the stone, or 
somewhat less, appears ; but the hidden 
part is most powerfully effective in ad- 
ding to the brilliancy. The apex of 
• the upper pyramid is cut off to a con- 
siderable extent, and the large facet thus 
formed is called the table : the corre- 
sponding facet below, formed by the 
truncation of the lower or hidden 
pyramid, is much smaUer, and is called 
the coUet, The rim where the setting 
takes hold, or, as we have described it, 
the junction of the bases of the pyramids, 
is called the girdle. There are thirty- 
two facets cut round the upper slanting 
surface of the stone, i.e., between the 
girdle and the table, and twenty-four 
on the lower part, between the girdle 
and the collet. All these facets have 
jiames by which they are known to the 
cutters ; and all the dimensions of the 
stone should, in order to produce the 



best effect, bear certain definite proper— 
tions to each other. The most fiavour— 
able form of brilliant for exhibiting the 
lustre of the stone is considered to bo 
a square, having the comers slightly 
rounded off ; but, of course, many stones 
will not admit of being cut to this form, 
without loss, and, therefore round, oval, 
pear shapes, &c., are perhaps more 
common. The stones lose about fifty 
per cent, in cutting, more or less, 
so that, to make a brilliant of one 
carat, a rough stone of two carats is 
Tequired. 

The chemical nature of th» diamond 
is well known. It consists of pure 
carbon ; identically the same thing as 
the soot from a kitchen chimney, but in 
different form. Sir Isaac Newton sus- 
pected, by its optical properties, that it 
was a combustible body; and its cha- 
racter has been subsequently proved 
beyond a doubt If sufficient heat be 
applied, diamonds will completely con- 
sume, combining with oxygen to form 
carbonic acid, precisely like charcoal or 
coke in an ordinary furnace. 

There have been many speculations 
as to the mode by which nature has 
effected this wonderM metamorphosis, 
• and many have been the attempts made 
to imitate her ; but hitherto she has 
kept her secret well, and baffled all her 
admiring followers. Sir David Brew- 
ster has suspected, by optical peculiari- 
ties exhibited in some examples, that 
•diamonds may not be of mineral origin, 
but may have resulted from the harden- 
ing of a kind of gum, something like 
amber. 

A curious substance has lately been 
found in the Brazilian mines, called 
^* Carbonado," or amorphous diamond — a 
kind of intermediate grade between 
diamond and charcoal, combining the 
hardness of the former with the black 
unformed character of the latter. Close 
inspection shows curious traces of a pas- 
sage between the two states ; and it is 
thought further examination of this 
substance may lead to some better in- 
sight than we at present possess, as to 
the chemical nature of the change. 
The diamond is totally insensible to 



Dianfkonda. 



l'T\ 



tHe action of any chemical reagents. Its 
specific gravity is about 3*5. 

The most characteristic quality of the 
diamond is its extreme hardness ; it is 
the hardest substance known. This 
quality was the earliest that attracted 
attention, the name being derived from 
the Greek *Pi^ajyM.% i.e. incapable of being 
crushed or subdued. For the comparison 
of hardness in different degrees, mine- 
ralogists have adopted a scale repre- 
sented by the following substances. 1, 
^c i % gypsum ; 3, calcareous spar ; 4, 
fiuor spar ; 5, phosphate of lime ; 6, 
felspar \^ 7, quartz ; 8, topaz ; 9, sap- 
phire and ruby ; 10, diconond. Any 
one of these substances will scratch all 
below it in the scale, and may be 
scratched by all above it. The dia- 
mond, therefore, as Dear as destructibility 
by abrasion is concerned, defies all 
nature. This quality renders it of con- 
siderable value for other purposes than 
ornament — as for cutting glass, and for 
working other stones, for the pivots of 
watch-work, &c. 

But, although the diamond is so hard, 
it is very easily broken, and, indeed, by 
a particular knack, it. may even be cut 
with a common pen-knife. This appa- 
rent anomaly is due to what is called 
its cleavage^ a result of the crystalline 
structura Many well-known substances, 
as slate for example, split or cleave with, 
peculiar facility yi certain definite di- 
rections, while they offer considerable re- 
sistance to fracture in all others. The 
diaiaond has this property, cleaving 
easily in no less than four directions^ 
parallel to the surfiices of the original 
octohedric crystal ; and, therefore, when 
moderate force is applied in either 
of these ways, the stone splits into 
pieces, Pliny, mentioning the great 
hardness of the diamond, states that if 
laid upon an anvU, and struck with a 
hammer, the steel would sooner give, 
way than the stone. This assertion is a 
matter of popular belief in the present 
day, but we would not recommend any 
possessor of a good diamond to try the 
experiment. The chances of some of 
the forces acting in the cleavage direc- 
tions are so great, that the stone would 



in all probability fly to pieces under the 
first blow. The truth is, that Pliny 
referred not to the diamond, but to the 
sapphire, which, though less hard than 
the diamond, cleaves only in one direc- 
tion, and might, therefore, withstand 
the test named. 

The cleaving property of the diamond 
is made useful in two ways in the manu- 
facture : first, by splitting the stones- 
when they contain flaws, and secondly, 
in the preparation of diamond powder. 
When a rough diamond is seen to contain 
a defect of sufficient extent to depreciate 
its value as a single gem, it is split in 
two, precisely at the flaw, so as to make 
two soimd stones. This is a very 
simple operation in appearance, done in 
a few seconds ; but it requires an amazing 
amount of skill to do it properly. The 
workman, by a sort of intuitive know- 
ledge, gained by long experience, knows, 
on a careful inspection of the stone, the 
exact direction which a cleavage plane 
passing through the flaw will take. 
Tracing this plane therefore to the exte- 
rior, he makes on the edge of the stone, 
precisely in that spot, a slight nick with 
another diamond. He then places a small 
knife in thsLt nick, gives it a light tap 
with a hammer, and the stone at once 
cleaves in two, directly through the 
flaw. This operation, in daily practice 
in the Amsterdam works, is one of the 
most elegant and instructive processes 
in the whole range of mineralogy. It 
is reported that Dr. WoUaston, cele- 
brated as almost the originator of the 
science of crystallography, once made a 
handsome sum by purchasing a large 
flawed diamond from Eundall and 
Bridge at a low price, and subsequently 
splitting it into smaller sound and valu- 
able stones ; the principle of the opera- 
tion not being then generally known. 

Another use of the cleavage principle 
is in the preparation of diamond powder. 
Small diamonds of inferior quality, are 
put into a steel mortar, and pounded 
and rubbed with a steel pestle, when 
they break up through their various 
-cleavage planes into still smaller pieces, 
and at last rub themselves into the 
finest dust, fit for use on the wheel. 



10 



Diamonds, 



The Ganse of the wonderful brUlianep 
of the diamond is not popularly known. 
It has no inherent luminous power ; it 
is simply transparent, like common glass, 
and yet^ if the latter were cut into the 
form of a brilliant, it could no more he 
mistaken for a real one than for a sap- 
phire or an emerald. The secret, there- 
fore, of the brilliancy of the diamond 
must lie in something other than its 
deamess or its transparency. It is 
owing to its great refractive power. 
When rays of white light pass through 
transparent substances ^ey are re- 
fracted, or bent out of their former 
course, and under certain circumstances 
are separated into their constituent ele- 
ments, and dispersed in the form of the 
well-known prismatic colours. The cut 
drops of glass chandeliers show a fami* 
liar example of these properties. Kow, 
the degree in which this effect is pro- 
duced by any substance depends on the 
re&active power it possesses, and it so 
happens that the diamond has this 
power in an extraordinarily high degree, 
its index of refraction being 2 '47, while 
that of glass, or rock crystal, is only 
about 1-6, and of water l*3i. The 
effect of this great refractive capability, 
particularly when aided by judicious 
cutting, is, instead of allowing the Ught 
to pass throughy to throw it about, back- 
wards and forwards in the body of the 
stone, and ultimately to dart it out again 
in all sorts of directions, and in the most 
brilliant array of mingled colours ; and 
this is this marvellous effect that meets 
the eye. Sir David Brewster has shown^ 
that the play of colours is enhanced by 
the small dieperme power of the di^ 
mond, in comparison with its refractive 
properties. 

It is often supposed that diamonds 
are essentially colourless, but this is a 
mistake; they exist of many colours, 
yellow, orange, pink^ blue, green, brown, 
and black. Three^fourths of the stones 
found are tinged with some colour or 
other, mostly pale yellow, or yellow 
brown* The perfectly pure and colour- 
less ones are selected as the most valu- 
able for the general market; but it 

1 North British Review, Nov. 1 862. 



sometimes happens that fine stones of a 
decided colour are more prized than 
white, from their peculiar rarity and 
beauty.* A blue diamond of about fifty- 
six carats, belonging to Mr. Hope, is a 
celebrated stone, combining the beauti- 
M colour of the sapphire with the fire 
and brilliancy of the diamond. 

The quality of diamonds depends upon 
their colour, purity, transparency, and 
freedom from flaws. Stones perfectly 
colourless, pure, clear, and free from all 
defects, are said to be of <Hhe first 
water ; " if they have slight imperfec- 
tions, they are "of the second water ;" 
and, if tinged with colour, or otherwise 
very defective, of " the third water." 

The value is estimated according to 
the weight, which is expressed in carats; 
one carat being about 205 French milli- 
grammes, or 3^ grains troy. 

For small stones, not exceeding one 
carat in weight, the value may be as- 
sumed approxixnately to be prcpartional 
to the weight ; but, as the stones increase 
in size, this rule does not apply — the 
larger ones being more rare, and there- 
fore having a value greater than is due 
to their mere size. To provide for this, 
it is generally assumed that, above one 
carat, the value shall increase as the 
square of the weight-— 4. #., that a stone 
double the weight of another shall have 
four times the value ; treble the weight, 
nine times the value.; ten times the 
weight, one hundred times the value, 
and so on. 

The money value of diamonds is a 
difficult subject to touch upon, as a 
distinction must always be drawn be- 
tween the retail price asked by jewellers 
from the public, and the real market 
price of the diamonds as sold by the 
dealers. Moreover, the value will al- 
ways vary according to the state of the 
market, as well as according to the 
quality and cut of the stones. As a 
rough approximation, brilliants of first- 
rate quality, and perfect in every respect, 
may be estimated at about 12^. per 
carat; reducible to half this, or even 

s A fine collection of coloured diamonds, be- 
longing to Mr. Tennant, are now exhibiting at 
the Kensington Museum. 



Diamonds, 



11 



less, for stones of inferior water. Ac- 
cording, therefore, to the rule of the 
weight above laid down, a diamond of 
half a carat might be estimated as worth 
6^. ; but one of two carats would be 
worth 2 X 2 X 12 = 48Z; one of five 
carats 6x5x12 = 300Z; and so on.^ 

This rule will, however, hold only up 
to the limit of stones in ordinary sale. 
Such as are veiy large and of exceptional 
production cannot be valued by any 
rule ; they are worth just what the state 
of the demand among crowned heads and 
millionaires will enable their holders to 
get for them. 

The general value of diamonds has 
been rising of late years ; for, though the 
production i39 not scan^, the demand, 
owing to general prosperity, and the 
extension of ornament to wider classes 
in society, is laigely on the increase. 

Imitations of diamonds are generally 
of one of the following three kmds : 

1. White Topaz, — This is necu'ly as 
hard as diamond, and about the same 
specific gravity, and may therefore be 
mistaken for it when tried by these 
tests. A London jeweller died lately in 
the belief that a fiiie stone he had come 
into the possession of was a valuable 
diamond, and left large legacies to be 
paid out of the proceeds of its sale; but 
it proved, on examination, to be only a 
white topaz, and of very little value. 
The difference may be recognised by the 

^ Referring to the square or best form of 
brilliants, the solid content of a cut stone, of 
proper proportions, is about f of that of the 
circumscribing parallelopipedon ; and, taking 
the Sp. gr. at 3*5, we shall obtnin the following 
rule. Let d :^ side of the square, or breadth 
across the girdle, and ^ = the thickness of th^ 
stone, from table to collet ; both in tenths of 
an inch ; — then 

Weight in carats = — _ . 

8-3 

In a well proportioned stone i sl^onl^ b« 

s=: i ^9 And ^e i^ule thus becomes 

Weight ^ -jgTgf 

w the ^^^ TOO, £ ^ ^i,, ■■. io thi^t th« 

18 to 30, 

worth of stones varies, ecetens parihus, as the 

9iixth power of their lineal dimensions. The 

height of the table aboye the girdle should be 

= J i ;— the depth of the collet below = 1 1, 

The breadth across the table should be = { (^. 



optical qualities^ which differ much in 
the two stones. 

2. Rock Crystal (Brighton diamonds, 
Irish diamonds, &c.)— This substance 
though hard enough to scratch glass, is 
much softer than diamond, and is easily 
soiatched by it It is abo much mferior 
in brilliimey and in .pecifio grayity. 

3. jPa<t«.-^Thi8, which is a glass 
prepared with metallic oxides, can be 
made equal to diamond in refractive 
power, and therefore can be given a 
great briUiancy; but it is very soft, 
Bofber even than common glass, and it 
does not retain its lustre. 

There is also a method of deception 
sometimes practised by what is called 
half-brilliant£i ; t. «. stones in the form 
of brilliants, in which the upper pyra- 
mid is a real diamond, and the lower 
a piece of some inferior stone, cemented 
to it ] the whole being set so as to hide 
the junction. When this deception is 
suspected, the stone should be taken 
out of its setting for examination. 

A very remarkable discovery has 
lately been made, that the chemical 
element horon^ the base of the common 
substance borax, may, by a peculiar pro- 
cess, be obtained in transparent crystals 
which possess the high refractive power 
of the diamond, and a hardness as great, 
if not greater. At present, the crystals 
produced have been too small to be of 
commercial value ; but it is quite possible 
that, hereafter, the discovery may prove 
to be of great importance. 

It only remains to mentioix a few 
particular stones celebrated for their 
size, and which have had, on account of 
their great value, a history of their own. 

The largest stone professing to be a 
diamond is the "Braganza'* found in 
Brazil in 1741, and preserved, in its 
rough state, in the Eoyal Treasury at 
Lisbon. It is as large as a hen's Qggy 
and weighs 1680 carats ; but doubts 
are entertained whether it may not be 
in reality only a white topaz and no 
diamond at all ; a supposition which, as 
the Portuguese Government decline to 
allow it to be cut or sufficiently ei* 
amined, would appear quite possible. 

The largest authenticated diamond 



12 



Diamonds, 



known is that of tKe Bajabi of Mattan 
in Borneo. It is of the purest water, 
pf a pear shape, and weighs 367 carats. 
It was found a century ago at Landack, 
and has been the object of many wars 
for its possession. 

The celebrated " Pitt " or " Kegent" 
diamond was found in 1702, in the 
mines of Farteal, twenty miles jfpom 
Masulipatam, by a slave, who having 
concealed its discovery from his em- 
ployers, offered it to a sailor on condition 
that he would give him his freedom. 
The sailor lured him on board his ship, 
threw him overboard, and sold the stone 
to the then Governor of Fort St George, 
whose name was Pitt, for lOOOZ. ; he 
quickly ran through the money and 
then hanged himself for remorse. The 
diamond was purchased from Pitt by 
the Eegent of France, for 135,000^. It 
weighed 410 carats in its 'rough state, 
but was cut into a fine brilliant of 137 
carats, thus losing two-thirds of its 




weight in the* operation. It is said ta 
be the finest diamond (though not the 
largest) in the world, in beauty of form, 
and purity of water. During the reign 
of terror, when the Tuileries were plun- 
dered, the diamond disappeared, along 
with all the other crown jewels ; but 
it turned up again, and was pledged by 
the Eepublic to a merchant in BerlinL 
Redeemed at a later period, it em- 
bellished the sword of Napoleon I., and 
was taken by the Prussians after the 
battle of Waterloo. It is now in the 
French crown, and was exhibited in the 
French Exhibition of 1855. 

The "Star of the South," another 
large brilliant, was also exhibited there : 
it was found lately in the Brazilian 
mines, and weighs 125 carats ; it is of 
an oval shape ; 35 millimetres long, 29 
wide, and 19 thick. It is very pure, 
but its colour is slightly inclining to 
pink. It is in private hands, and for 
sale. 





Section of " SUf.r of the Smith.** 



Under Surface. 



Upper Surface. 



The " Sancy " diamond, of 53 J carats, 
has a singular history. It came origi- 
nally from India, and, about the fifteenth 
century, was in the possession of the 
luxurious Duke of Burgundy, Charles the 
Bold, who wore it, probably as a talisman, 
in the unfortunate battle of Nancy, in 
Switzerland, where he was killed. A 
common Swiss soldier, who discovered 
the body in a ditch, found the jewel in 
the clothes, and, not knowing its value, 
sold it for a florin to a Swiss priest, 
who transferred it to the hands of the 
Confederacy. It; subsequently came 
into the possession of the King of 
"^ortugal, who, in 1489, being in want 



of money, parted with it to a French 
trader. In the sixteenth century it 
found its way into the hands of a 
Huguenot nobleman, the Baron of Sancy, 
who happened to be in Soleure when 
King Henry III. was trying to negotiate 
a loan. Sancy offered him, as a true 
subject, the diamond, and his offer was 
accepted; but the messenger who was 
entrusted to convey it to the king (some 
accounts say Sancy himself) was way- 
laid and murdered, but had time before 
his death to swallow the stone, which 
subsequently was found in the stomach 
of the corpse. The stone was next 
traced into the possession of James II. 



Diamonds. 



13 



of England, who took it with him when 
he fled to France in 1688, and after- 
wards, when he was in distress for 
money, parted with it to Louis XIY. for 
25,000^. — ^and Louis XV. is said to have 
worn it in the clasp of his hat at his 
coronation. It vanished in 1792, but 
reappeared in the !N'apoleon era, and 
was sold for 600,000 silver rubles to the 
Emperor of Eussia, in whose possession 
it still remains. 

The "Nassack" diamond was cap- 
tured during the Mahratta war in Lidia, 
in the Peishwa's baggage, by the com- 
bined armies under the Marquis of 
Hastings ; and, after changing hands seve- 
ral times, was purchased, about twenty 
years ago, by the Marquis of Westminster. 



It was afterwards partly re-cut by Hunt 
and Eoskell, ^and is now a beautiful 
colourless stone, weighing 78 J carats. It 
is of a triangular or pear shape. 

Many other large diamonds might 
be mentioned, each of which has a his- 
tory, but perhaps the most interesting 
of all, is our own great diamond, the 
celebrated Koh-i-noor ; the story of 
which would make a very fair true 
romance of three goodly volumes. 

Its origin is older than any historical 
records reveal, but it can be traced 
as far back as the beginning of the 
fourteenth century, when it came into 
the treasuiy of Delhi ; and from this 
time it became intimately associated 
with the entire history of the Indian 




iSAope of the ** Kohr-i-noor " as exhibiUd vn, Upper Sur/cuse in its present state, 
the Crystal PaUice in 1851. 



Under Surface. 



wars and dynasties, until, on the late 
annexation of the Punjab, it was taken 
possession of by our government, 
brought' to England in 1850, and pre- 
sented to the Queen. It was shown at 
the international Exhibition of 1851, 
in the state it was received, weighing 
186 carats ; but it was so ba(Uy cut that 
its brilliancy scarcely exceeded that of a 
piece of crystal, and it had several flaws 
and defects in its structure. The Queen, 



after taking advice from competent 
judges, decided to have it recut ; which 
was done in London (by workmen ex- 
pressly brought over from Amsterdam 
for the purpose) in 1852. It has now 
the form of a regular brilliant ; and, 
though its weight has been reduced to 
102-J carats, it has become, what it never 
was before, a most splendid jewel, 
worthy of its royal mistress, whose 
unsullied diadem may it long adorn ! ^ 



' ^ The illustrations to this reprint of the paper have been kindly supplied by Professor 
Tennant. 



POSTSCRIPT. 



Since writing tHe ttbove, I have had the opporttmity of 
inapeoting, along with Profefiisor Tennaaty a rety beautiful 
diamond of extraordinary size, lately found in the Brazilsi 
and in the possession of Mr. Dresden. The following cuts 
show its size and shape; — it weighs 76J carats, nearly as 
heavy as the Nassack diamond, and is decidedly one of the 
finest and purest in colour known. 






ApHl, 1861. 






A DESCRIPTION OF 

THE IMPERIAL STATE CROWN, 

•PRESERVED IN THlfi JEWEL HOUSE AT THE TOWER OF LONDON. 

BY PROFESSOR TENNANT, OF KING'S COLLEGE. 
[Read before the London and Middlesex Archssological Society^ July 7, 185S.] 

The Imperial State Crown of Her Majesty Queen Victoria 
was made by Messrs. Rundell and Bridge in the year 1838, with 
jewels taken from old Crowns, and others furnished by command 
of Her Majesty. It consists of diamonds, pearls^ rubies, sapphires, 
and emeralds, set in silver and gold ; it has a crimson velvet cap 
with ermine border, and is lined with white silk. Its gross weight 
is 39 oz. Sdwts. Troy. The lower part of the band, above the 
ermine border, consists of a row of one hundred and twenty-nine 
pearls, and the upper part of the band a row of one hundred and 
twelve pearls, between which, in front of the Crown, is a large 
sapphire (partly drilled), purchased for the Orown by His Majesty 
King George the Fourth. At the back is a sapphire of smaller 
size, and six other sapphires (three on each side), between which 
are eight emeralds. 

Above and below the seven sapphires are fourteen diamonds, 
and around the eight emeralds one hundred and twenty-eight 
diamonds. Between the emeralds and sapphires are sixteen 
trefoil ornaments, containing one hundred and sixty diamonds. 
Above the band are eight sapphires surmounted by eight dia- 
monds, between which are eight festoons consisting of one 
hundred and forty-eight diamonds. 

In the front of the Crown, and in the centre of a diamond 
Maltese cross, is the famous ruby said to have been given to 
Edward Prince of Wales, son of Edward the Third, called the 
Black Prince, by Don Pedro, King of Castile, after the battle of 
Najera, near Vittoria, A. d. 1367. This ruby was worn in the 
helmet of Henry the Fifth at the battle of Agincourt, a.d. 1415. 
It is pierced quite through after the Eastern custom, the upper 
part of the piercing being filled up by a small ruby. Around 
this ruby, to form the cross, are seventy-five brilliant diamonds. 



16 The hnpcrial Croion of England. 

Tliree other Maltese crosses, forming the two sides and back of 
the Crown, have emerald centres, and contain respectively one 
hundred and thirty-two, one hundred and twenty-four, -and one 
hundred and thirty brilliant diamonds. 

Between the four Maltese crosses are four ornaments in the 
form of the French fleur-de-lis, with four rubies in the centres, 
and surrounded by rose diamonds, containing respectively eighty- 
five, eighty-six, eighty-six, and eighty-seven rose diamonds. 

From the Maltese crosses issue four imperial arches composed ' 
of oak leaves and acorns ; the leaves containing seven hundred 
and twenty-eight rose, table, and brilliant diamonds ; thirty-two 
■pearls forming the acoms, set in cups containing fifty-four rose 
diamonds and one table diamond. The total number of diamonds 
in the arches and acorns is one hundred and eight brilliant, one 
hundred and sixteen table, and five hundred and fifty-nine rose 
diamonds. 

From the upper part of the arches are suspended four lai^e 
pendant pear-shaped pearls, with rose diamond caps, containing 
twelve rose diamonds, and stems containing twenty-four very 
small rose diamonds. Above the arch stands the mound, con- 
taining in the lower hemisphere three hundred and four brilliants, 
and in the upper two hundred and forty-four brilliants ; the zone 
and arc being composed of thirty-three rose diamonds. The 
cross on the summit has a rose-cut sapphire in the centre, sur- 
rounded by four large brilliants, and one hundred and eight 
smaller brilliants. 

Summary of Jewels comprised in the Grown. 

1 Large ruby irregularly polished. 
1 Large broad-spread sapphire. 
16 Sapphires. 
11 Emeralds. 
4 Rubies. 
IfiQS Brilliant diamonds. 
1273 Rose diamonds. 
147 Table diamonds. 
4 Drop-shaped pearls. 
■ 273 Pearls.