Mexico weekly ledger., 1876-12-28
The Diamond.

When the diamond is rubbed it be-
comes positively electrical, even before
being cut, in which it differs from all
other gems. When, after exposure to
direct sunlight, it is suddenly placed in
darkness, it shows phospnorescence,
and the evolution of light continues for
some time. 1t is not acted upon by any
acid or alkali. But it may be con-
sumed and completely oxidized to car
bonic acid at a high heat in the atmos.
phere. 1t is SO difficult to burn that the
ordinary blow pipe flame has no effect
uponit. 1t may be heated To whiteness
in a closed crucible without change, but
it begins to burn in a mutfle at the melt.
ing point of silver. At a high heat
with nitrate of potash it is rapidly de-
composed. .
Miners are generally not familiar
with the appearance of diamonds in the
rough state, and would most likely mis-
take them, if found, for chalcedony or
some similar mineral. Ii in crystal
form it would be to them a crystal only
interesting for the moment, to be soon
thrown aside as useless. l have
heard of a case where a beauti-
full crystal, supposed to be a diamond,
being found in some placer mine in
California, was put to the following
test: 1t was placed on an anvil ana
struck a heavy blow with q sledge
hammer, it being assumed that the dis-
mond, being the hardest of known sub
stances, could not be broken. The idea
is more ancient than is generally sup
posed. The statement has been made
by Pliny, but it is doubtful if he ever
made the experiment himself. In speak
ing of a diamond. he says that it can
not be crushed, but would split the
hammers and anvils in the attempt. 1t
is certain that this is a mistake. The
diamond can be split on the edge of d
knife, and even a light blow with q ham
mel might destroy the most costly gem.
The diamond is supposed to be of
vegetable origin, and is believed, by
those who have studied it carefully, to
be produced by slow decomposition of
vegetable or bituminous matters. Zone
large diamond having q black spotin it
was cut in two, and the defect was
found to be vegetable mud enclosed in
the crystal.
1t requires practice to judge of the
diamond in lis rough state. A rough
diamond of the first water would be
hardly recognized by the uneducated
eye as a valuable gem. In describing
the diamond many of it's characteristics
are visible only in its cut state. Half
the stone is sometimes cut away before
a perfect gem a be produced. The
diamond washers of Brazil rub the
stones together and produce a peculiar
grating sound, from which they assume
to judge of their value.
There is a peculiar appearance about
a rough diamond which can hardly be
described. | question if any written
description would convey to the reader
a correct idea of what they are exactly
like. 1t is easy to say that they possess
a peculiar luster, like spermaceti, but
who would feel certain of the identity
OF diamond from such a description
Once seen, this peculiar lustre becomes
impressed on the mind. To educate
the eye, models of rough diamonds are
made at Amsterdam for the use OF
p~rospectors. and they are found ex.
tremely useful.
Newton first suggested the probable
kOJ Va AN uLaLAlohu bCtIl2 COAuDuSIlDlG
lie was led to this opinion by observing
its power of refracting light SO strongly,
1t was in 1875 that he advanced this
theory. In 1894 the members of the
Academy of Florence succeeded, by
means of powerful lenses, in consuming
diamonds. Lavoisier and others proved
that the diamond was not evaporated,
as supposed by the aeademicians, but
was actually burned. Lavoisier found
by his experiment that if air was ex.
Guided no decomposition took place,
He burned diamonds in close vessel:
with powerful burning-glasses, anG
found that carbonic acid was produced,
and discovered and announced the
striking similarity between their nature
and that of charcoal.-NeW York Sch0o
Journal.