THE GEMS.
PRECIOUS STONES OE GEMS.
PRecious stones
or gems are such minerals as, either from their beauty or other
valuable properties, have become the subject of the arts or trade, and
are used as ornaments, or employed by jewellers. In order to appreciate
more fully such minerals as may possess superior virtue, it is our
present object to consider them in reference to their scientific and
practical value.
DIVISION OF GEMS.
Gems
are generally classed as follows: 1st, real gems, or jewels ; and 2d,
semi-gems, or also precious stones. The first comprise such minerals as
combine, within a small space, either vivid or soft and agreeable
colors, with a high degree of lustre, usually termed fire, as well as
hardnes"s; the second possess these characters in a less degree, and
occur often semi-transparent or translucent, and in larger formless
masses. It is, however, impossible to draw a strict line between them,
as the conventional value put upon the one or the other also affects
their character ; for very often some, which are generally considered
as belonging to the second class, may be valued, for their peculiar
properties, much higher than some of the first class.
