Missouri Valley times. [volume] (Missouri Valley, Iowa) 1874-1931, 1910-09-29
THE BLACK DIAMOND.
Il Is One Of the Gu, 49, {, !,
Mineral Kiny.viii.
A PUZZLE TO SCIENTISTS.

Nature Has In Some Peculiar Way
Produced This Rars Form Of Carbon
and Then Thrown Away the Secret
Of the Proeess-Found Only In Brazil.
The term "black diamonds" is some.
times jokingly applied to ordinary coal
which we burn III our furnaces. but
the real "black diamonds" of COM
blerce are among the most unique min.
er,ll products of the world. and they
serve u purpose In the Industrial world
that makes them Of great value. The
black diamonds are pure carbon aud
yet in no outward appearance resem-
be the diamonds which we are accus-
toned TO wear as ornaments. They
are slightly harder than the crystal or
gem diamonds and. in fact. about the
hardest substance known.
Black diamonds. or carbons. are
among the greutest curiosities Of the
mineral Kingdom. They are without
crystalline form and are found in ir.
regular pieces. ranging III size from,
half IL carat up to three. four and five
hundred c,lrats. They are dark gray,
black or brownish In color and opaque.
The real diamond of the jewelry trade
ts also pure carbon. but translucent
and crystalline In form Two objects
su alike in composition could not be
found no opposite in appearance us
these two forms of carbon.
Another peculiar thing about the
black diamonds is that they are found
only in one locality in the world. They
come from Il very small section of Bra
zil not more than 2e..5 miles squire in
area. Outside. of this limited territory
no pure black diamonds have ever
been found.
What peculiar freak of nature caus.
ell tue deposition of the black dia-
monds in this section Of the world and
nowhere else Is one of the mysteries
which science has failed to explain.
None Of them has been found in the
gteat Kimberley diamond regions.
where the crystal form Of diamonds
have for 10 long been mined.
The whole origin of the black di8.
fiOnd is. therefore. u scientific enigma.
Naturally the question Ia raised. "Of
what use is Il black diamondY' No
one would care to wear one of these
diamonds. which resembles piece of
cU,ll more than IL real diamond. and sc
Far no one has popularized the black
gems as the black pearl has been.
Nevertheless the black diaplonds serve
q most important and useful function
IL the Industrial world.
This pure blck carbon Is not Only
harder than the real diamond. but
tougher aud not SO brittle as the gem
Consequently It is of great value for
.:lany mechanical purposes and partic-
ularly for boring with diamond drills.
in diamond drilling the tips of the
drills are studded with carbon. or
black diamonds. and when the bores
are deep the pressure Is 80 great that
the gem diamonds would he crushed in
the process. l,ut the carbon ressts
this continued pressure and slowl;,
eats down into the rocks.
In diamond drill work the carbon is
set in circular pieces of soft steel or
iron. called bits. and these bits are at.
tached to tubing. Armed with these
black diamond teeth. the drills push
their way down under severe pressure
10 depth Of five and six thousand
feet. cutting through the hardest kind
Of rock. Some black diamonds are
much harder than others. and there is
aO way to determine by the color the
difference III the degree of toughness.
Black diamonds or pure carbon ure
not by any means cheap. and the own
ers Of the mines In Brazil where they
arc gathered are making a good thing
out of their monopoly. There is no
known substance that can take the
place of carbon in drills in boring for
gold. silver. copper and other minera.
deposits. Before the black diamonds
Of l;':lzil were discovered it was I'M
possible TO make borings.
When the carbon was first introduc
Ell IN our Industries 1t was used IL
diamOnd saws for cutting stones. mar
bic and similar substances. Then the
price advanced SO that the carbon was
found too costly for such use and bort
was substituted for stone cutting. Bort
Is really un imperfect crystal or gem
diamond. but 1t is too brittle for use
III drills. Consequently bort has tak.
Ell the place of black diamonds for
EtOne cutting. nnd the latter have been
restricted almost entirely to diamond
drilling purposes.
The average size Of Black diamonds
used III the drills ranges from two tn
Eve clrats. but the larger specimens
give mucE better results. They cos,
more. hut they last longer. Consp.
quently there is II grcnter demand for
the larger pieces Of pure carbon. and
the price Is sometimes run UP to pre-
alum figures for unusual specimens.
The fear that the supply of black
diamonds may some day give out and
inlru!yzp the diamond drilling industry
has stimulated l,rOslmctors to syst,.
iyiutic scare h for new deposits. but so
fur they have NOT lM"ti successful. Oh,
tie other hand. scientists have l,uru
making Il close study of the chemical
conditions which have produced thu
l.iack diamonds. but their manufacture
Il ;,n,mrently about IS difficult as the
making Of the gem diamonds. II is
:.t,ssible under certain conditions to
lake either. hut not in sizes sufficient
~ be Of amy commercial value. Ma.
,lre in some peculiar way has made
these rare products and then thrown
Il 10 secret of the lyfUcsss away. II any
.an can ever unlock or 1nd that re-