The central Presbyterian. [volume] (Richmond, Va.) 1856-1908, 1870-03-30
Something About Gold.

Gold is found sparingly in many hard
rocks, such as granite, mica slate, chlorite-
slate, and clay slate, and sometimes even
in limestone and other similar rocks. 1t oc
ours far more abundantly in quartz, pure
unmixed flint, or slick. In igneous or met
amorphic rocks, the quartz usually occurs in
veins, or in large, irregular punches or Jumps,
with veins diverging from them. These veins
are most commonly only few feet wide, and
for the most part traverse the rocks in yer
teal or highly inclined position. Some
times, however, veins or irregular masses
occur many yards across in every direction;
and sometimes, but very rarely, quartz is
found in such abundance as to make what
even might be called hills of itself. The
gold is disseminated in this quartz, some
times in such exceedingly minute particles
as to be invisible, not only to the naked eye,
but even to the eye aided by a powerful
lens. Most commonly, the gold is seen as
little yellow specks, fakes, OF grains scat
tered through the quartz. When the quartz
has crystalline structure, which it often
has, little nests of gold, likewise crystalline,
may be seen embedded between the inter
lacing crystals of the quartz. Where the
interstices in the quartz are large, these are
sometimes entirely filled up with gold; but
not unfrequenty irregular holes and crew
ices seem to have been formed in the quartz
by decomposition or rottenness, which have
sometimes been subsequently filled with gold.
In these cases, the gold assumes irregular
forms, such as melted lead will when poured
into water-forms which have given people
the idea of the gold having been deposited
in state of fusion, notion in all proba-
bility utterly unfounded. How the gold got
in the quartz, is point at present so uncer-
tain, that no man of science would take upon
himself, the responsibility of answering the
question. The size of the irregular Jumps
thus entangled in the quartz varies greatly,
the largest hitherto known single lump in
the world being an Australian one of 2,l66
ounces weight. It's, however, usually found
in small fakes, grains, and dentritc strings,
weighing only few grains.
Whenever the moving waters of the sea,
by which drift materials were formed and
deposited, attacked rock containing gold,
it would of course break off Jumps of it,
Just as of any other, and equally wash, roll,
and knock it about, and thus break it into
smaller fragments, round it into pebbles, and
grind it into sand. In this way. much of
the gold would be knocked out of the rock,
and much water worn gold accumulated, or
water-worn fragments of gold and quartz
together.
From this point of time, however, there
is remarkable difference observable in the
action of the water on the gold, and on the
rock which contains no gold. All kinds Of
rock, or earth, or stone, at all events all the
common kinds, are pretty nearly of the same
specific gravity-that is to say, of the same
weight, bulk for bulk. Chalk, clay, lime
stone, compact sandstone, granite, marble,
basalt, have all specific GRANTEES varying
from to Shat is, they are twice or thrice
the weight of their bulk of water. Pure
gold has a specific gravity of 10, or is nine
teen times as heavy as its bulk of water;
and the most impure ore of gold that occurs
in nature has at least specific gravity of
IL to Is. Gold is about six or seven times
as heavy as quartz, or any other stone