Bryan daily eagle and pilot. [volume] (Bryan, Tex.) 1909-1918, 1910-01-04
THE BLACK DIAMOND
II Is One Of the Curiosities Of the
Mineral Kingdom.
A PUZZLE TO SCIENTISTS,
Mature Has In Some Peculiar Way
Produced This Rare Form Of Carbon
and Then Thrown Away the sserst
Of the Proeess-Found Only In Brazil.

merce are among the most unique min
rral products of the world. and they
serve a purpose In the industrial world
that makes them Of great value. Tho
black diamonds are pure carbon aud
yet In no outward appearance resem-
bic 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 greatest curiosities OF the
mineral kingdom They are without
crystalline form and are found In IA
regular pieces. ranging In size FROM
half carat up TO three. four and five
hundred carats They are dark gray,
black or brownish In color and opaque.
The real diamond OF the jewelry trade
Is also pure carbon. but translucent
and crystalline In form. Two objects
so alike In composition could not be
found so opposite in appearance as
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 n very small section OF Bra
I'll not more than 225 miles square IN
area. Outside of this limited territory
no pure black diamonds have ever
been found.
What peculiar freak of nature caus
ed the deposition OF the black dis
monds In this section OF the world and
nowhere else Is one of the mysteries
i which science has failed TO explain.
None OF them has been found In the
great Kimberley diamond regions,
where the crystal form of diamonds
have for so long been mined.
/ The whole origin OF the black dia-
mond Is. therefore. scientific enigma.
Naturally the question Is raised. "Of
what use is black diamondr' No
one would care TO wear one OF these
diamonds. which resembles piece IL
coal more than real diamond. and so
far no one has popularized the black
gems as the black pearl has been.
Nevertheless the black diamonds serve
most important and useful function
In the Industrial world.
This pure black carbon Is not only
harder than the real diamond. but
tougher aud not so brittle as the gem.
Consequently Il Is OF great value for
many mechanical purposes aud 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 so great that
the gem diamonds would be crushed In
the process but the carbon resists
this continued pressure aud slowly
eats down into the rocks.
In diamond drill work the carbon Is
set In circular pieces OF soft steel OF
iron. called bits. and these bits are at
tached u tubing Armed with these
black diamond teeth. the drills pusi
their way down under severe pressur.
10 n depth OF i've and six thousand
feet. cutting through the hardest kind
of rock. Some black diamonds are
much harder than others. aud there Is
no way to determine by the color th'
difference In the degree OF toughness.
Black diamonds or pure carbon ars
not by any means cheap. and the own
ers OF the mines In Brazil where the,
are gathered are making good thini
out OF their monopoly. There Is ~
known substance that can take th'
place Of carbon In drills In boring fo
gold, silver. copper and other miheFa
deposits. Before the black diamond
of Brazil were discovered II was I'M
possible TO make borings.
When the carbon was first introduc
cd In our Industries IL was used Il
diamond saws for cutting stones, mar
bile and similar substances. Then tn
price advanced SO that the carbon wa
found too costly for such use. aud Dor
A., was substituted for stone cutting. Boz
, is really an imperfect crystal or get
! diamond. but II is too brittle for Us
. In drills. Consequently bort has tai
r en- the place OF black diamonds fo
!. stone cutting. aud the latter have bee
:. restricted almost entirely 20 damon
4 drilling purposes.
The average size OF black diamond
used In the drills ranges from two
Eve carats. bur the larger specimen
give much better results. They Co
more, but they last longer. Cons
= auently there is greater demand e
- the larger pieces of pure carbon. nj
= the prlce l. sometimes run up TO pr
= MUM figures for unusual specimens.
= The fear that the supply OF bla'
diamonds may some day give out al
= paralyze the diamond drilling indust
= has stimulated prospectors to syst
= matte search for new deposits. but
- far they have not been successful. I
- the other hand. scientists have De-
~ making a lose study OF the chemic
30 conditions which have produced U
~ black diamonds, but their manufactu
:. Is apparently about as difficult as Z
- making Of the gem diamonds. u
possible under certain conditions
- make either. but not In sizes sufiicie
y, TO be OF any commercial value. \
- ture In some peculiar way has ma
~ these rare products and then thro'
:. the secret OF the process away IL a
"A man can ever unlock or and that
cret he may cause panic IN the q
mond trade.-Scientiic American.