The chrysolite, peridot, and olivine differ in color, but are
practically of the same composition.
The chrysolite proper is of a pale greenish-yellow color, the peridot a
deep olive-green, and the olivine of a yellowish or light olive-green
color; these stones also shade into brown. They crystallize on the
rhombic system, are transparent to translucent, 6.5 to 7. in the scale
of hardness, and 3.3 to 3.5 in specific gravity.
The cleavage is distinct, fracture conchoidal, refraction double, and
lustre vitreous, and in the olivines somewhat greasy.
These stones are easily affected by sulphuric acid, but are infusible
before the blow-pipe, excepting some kinds containing much iron.
With borax, they melt to a pale-green transparent glass.
Chrysolites are composed of silica, magnesia, and oxide of iron.
Perfectly crystallized chrysolites are brought from Constantinople, but
the exact locality where they are found is unknown.
Less distinct specimens occur at Vesuvius, Mexico, the isle of Bourbon,
Auvergne, Egypt, Natolia, Brazil, Germany, Pegu, Ceylon, Switzerland,
and North America.
Peridots are distinguished by being the only precious stones that have
literally dropped from heaven, as they have been found in meteorites.
The Oriental chrysolite of commerce is true chrysoberyl, and is harder
and heavier than chrysolite, and the stone called Ceylon chrysolite is
a greenish-yellow tourmaline, which is easily distinguished, as it is
also harder while considerably lighter than the chrysolite.
The green garnet is of a pronounced green color, and is harder and
heavier than the olivine or chrysolite. Although suitable for mounting
in brooches and other ornaments, these stones are not sufficiently hard
for the rough usage as ring-stones.