Audubon County Republican. [volume] (Audubon, Audubon Co., Iowa) 1885-1894, 1889-11-14
GEMS AND PRECIOUS STONES
Estimated Yield OF Brazil, India
I;orneo and AustrniIo

Estimated Yield or Brazii, India
Borneo and Australia.
10 reference 10 The interesting article O
Prof. T. J.. simmonds on the search for gem
and precious stones, read before tb
Society OF Arts OF England recently, reprInte
In your issue OF October IA, allow me to sus
gest few corrections. Prof Simmonds csti
mates the yield OF the Brazilian damon,
mines at 100000 annually, while a it'll
later on he says that the yield has dwindle,
TO 1900 carats, which at the outside will no
yield more than e. to 60 a carat, and that o
India, Borneo and Australia at goo, 900
when these latter figures would probabl
cover the annual product OF Brazil as well q
that OF the other three countries named. Aus
tralis produces SO very little as scarcely to b,
factor in the computation. Even before tn,
opening OF the African mine, In 1857, the esti
mated value Of the products of Brazil from
1851 to 1857 was only 81, 1855, 900, or sornethiu,
over 100000 per annum, at Q time whe,
Brazilian diamsnds commanded higher pricr
than at present, and now they produce mucl
loss. His statement that the opal is out O.
fashion would have been true several year
ago, but Is not to-day, when more OF thee,
stones arc sold, and at better prices, thar
ever before.
The carat Is given as g. ia grains; whcrea.
since there are Isl 5 English diamond carat
In an English Troy ounce Of $50 grains, az
English carat would DO s. l8S3l1S Troy grains
or, less exact, 3.l6S. A diamand carat is al
ways divided into four diamond grains equal
ing 1904 Of Troy grain. II 81. 103 grant
equal an English Troy ounce, carat wouIt
be .2o5304 Of gram.
An International syndicate composed Of
OF London, Psris and Amsterdam jewelers.
wish hing TO establish a uniform carat, In 1877;
confirmed rs, however, as tho true value Of
q carat, In which case We have l5l.76 earats IL
an ounce Troy.
These may seem trifing differences, but vel
they are enough to affect q SIC, 90 lot Of dla.
monds, worth 500 carat, to the amount Of
$4S3 between the 3.l74 carat and the 8. l6S
carat, aud $3.50 between the former and tb,
syndicate carat.
the preference TO imperial jade, which b.
mentions several times under the head OF the
jade quarries OF Burma, as this (FeitsmD i'm.
Periai jade is tadoite, not jade, and is general.
ly only emerald green In spots or streaks, the
mass being dead white, lending a vIvidncss
to the green, which occasionally almost rivals
the ensrald and has the hardness of
or the articles OF jade shown BY the New
zealand Court at the Colonial Exhibition,
England, Prof. Simmonds says: "Evidenclna
tho skill OF the Maoris In working this hard
material, the second in this respect to the
diamond, although much more fragile,n etc.
This would leave one to infer that the material
possesses great hardness, when IN fact, the
hardness OF jade Is only as, less even than
that OF rock crystal, and It can be worked
with sand, by which laborious means, un.
doubted!y, oil OF the aboriginal ornaments OF
the MAORI were made. So. far as its fragility
Is concerned, 1t is the toughest Of all known
minerals, and this is the reason why 1t is so
difficult to work. 1t would require less time
to polish twenty surfaces OF agate, which 10
harder than jade, than IL would to polish one
OF jade on the same wheel. Krantz, the
mineral dealer OF Bonn, having a SO. pound
piece OF jade which he wished broken Into
small hand specimens, friend kindly offered
him the use Of large bslf-ton trip hammer
to break 1t with. At the first blow the
hammer was demolished aud the Jade was
only fractured by being heated and thrown
into cold water.
We frequently hear minerals or gems loose.
ly spoken of as second or third In hardness TO
the diamond. On the Mohs scale OF hardness
the diamond Is represented by 10, the sap
phire BY, Q, topaz and quartz 4; but, al
though the difference on the scale 10 only i.
there 10 room for eversl substances between
the diamond and the sapphire; and, as we
have no such substance In nature We place
diamond on 10. In reality, so great is the
difference between these two substances that,
u tho hardness OF the sapphire Is g. that OF
the diamond would be fully 100, relatively 10
the rest Of the scale. Prof. SlInmonds also
says that coral has the hardness and brilliancy
OF agate. Quartz and agate are placed at
In the Mohs scale, whereas coral has only the
hardness Of about 5, the same as that OF mar.
pie tcslcitei, and can be scratched by fuorite,
II Is impossible to see how this opaque sub,
stance can be said to ''shne like a garnet,
with the tint Of the ruby"
A word, In closing, about the hardness of
agate and rock crystal. Mlneraloglcslly these
are classed together at Z. but In reality the
crystalline varieties should be Z, ard the
cryptic crystalline varieties 10, since thev Will!
readily scratch quartz and quartz will not
scratch them.-George F. RItz, IL Science.