The Caldwell tribune. [volume] (Caldwell, Idaho Territory [Idaho]) 1883-1928, 1888-01-14
GEMS AND PRECIOUS sroNss.
Estimated Yield of Erazil, IndIn,
Borneo and Australia.

4
Borneo and Australia.
In reference to the interesting article of
| Prof. 2. L. Sinmonds on the search for gems
and precious stones, read before the
Society of Arts OF England recently, rerrinted
! In your issue of October IA, allow me to sug-
gest few corrections. Prof Simmonds esti-
mates the yield Of the Brazilian diamond
mines at eS0O,00 annually, while a Iiill.
later on he says that the yield has dwinlied
TO ~, 700 carats, which at the outside will not
yield more than e. to 50 carat, and that Of
India. Borneo and Australia at e2a,0 0t,
when these latter fisures would probably
cover the annual product of Brazil as well as
that of the other three countries named. Aus
tralia produces so very little as scarcely to be
factor in the computation. Even before tie
opening of the African mine, in 1861, tue esti-
mated value of the products of Brazil from
1851 TO 1861 was only 81 ,SSS, OJ0, or something
over e300,0OO per annum, ut a time when
Brazilian diamands commanded higher price
than at present, and now they produce muci,
less. His statement that the opal is out Of
fashion would have beeh true several years
ago, but is not today when more Of these
stones are sold, and at better prices, tina
ever before.
The carat is given as 3. ia grains; whereas,
since there are Isl English Diamond carals
in an English Troy ounce of 4SO grains, an
English carat would be 16S3l6S Troy grains,
or, less exact, 3.16S A dianand carat is al.
ways divided into four diamond grains equal
ing .792O74 of Troy grain. If 81. 1903 grains
equal an English Troy ounce a carat would
be .2O53O4 Of gram.
An International syndicate composed of
OF London, Paris and Amsterdam jewelers.
wishing to establish a uniform carat, in 1877
confirmed q 5, however, as the true value of
q carat, in which case we have Isl 76 carats in
an ounce Troy.
These may seem trifing differences, but yet
they are enough to affect $l0,0 % lot of dia-
monds, worth 500 carat, to the amount of
$4S3 between the a174 carat and the 3.l6S
carat, and $3.50 between the former and the
syndicate carat.
1t would perhaps have been better to make
the preference to imperial jade, which he
mentions several times under the mead of the
1ade-quarries of Burma, as this IRE tsu) i'm
perial jade is jadeite, not jade, and is general
ly only emerald green In spots or streaks, the
mass being dead white, Lending vividness
to the green, which occasionally almost rivals
the emerald and has the hardness of z.
OF the articles of jade shown by the New
Zealand Court at the Colonial Exhibition,
England, Prof Simmonds says: '.Evidencng
the skill of the Maoris in working this hard
material, the second in this respect to the
diamond, although much more fragile" etc
This would leave one to infer that the material
possesses great hardness, when in fact, the
hardness of jade is only 6.5, less even than
that of rock crystal, and 1t can be worked
with sand, BY which laborious means, I'M
doubleday all of the aboriginal ornaments of
the Maori were made. So far as its fragility
is concerned, it is the toughest of all known
minerals, and this is the reason why it is so
difficult to work. 1t would require less time
70 .Nplio fxrn IF 60 4.
harder than jade, than it 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 half-ton trip hammer
to break it with. At the first blow the
hammer was demolished and 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 8, topaz and quartz z; but, al
though the difference on the scale is only l,
there Is room for several 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,
If the hardness OF the sapphire is 8, that Of
the diamond would be fully 100, relatively to
the rest of the scale. Prof. Simmonds also
says that coral has the hardness and brillancy
OF agate. Quartz and agate are placed att
In the Mohs SCALE whereas coral has only the
hardness of about 8, the same as that Of mar
BILE (calcite), and can be scratched BY fluorite.
1t is impossible to see how this opaque sub
stance can be said to ''shine like garnet,
with the tint of the ruby"
A word, in closing, about the hardness of
agate and rock crystal. Mineralogically these
are classed together at Z. but in reality the
crystalline varieties should be z, and the
crypto-crystailine varieties 7.3, since they will
readily scratch quartz and quartz will not
scratch them.-Georye r. Runz, IN Science.