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Two
varieties of garnet, almandite and pyrope, may exhibit the dark
blood-red color especially ascribed to garnet. Almandite or almandine
garnet derives its name from Alabanda, a city of Asia Minor, in the
ancient district of Caria, whence garnet was first brought to the
Romans. The finest almandite for a long time came from near the city of
Sirian, in the old province of Pegu, Lower Burmah. While this was the
center of supply, it is not known just where the garnets were obtained.
Such garnets are still known as "Sirian" garnets. Their color tends
toward the violet of the ruby, and gives them a high value. There are
several localities in northern India where almandite is mined on a
large scale, and the stone is much used in Indian jewelry. Some of
these localities are Condapilly, Sarwar, and Cacoria/ Almandite is also
found in Brazil, in Australia, in several localities in the Alps, and
in the United States. Stones from all these regions are found suitable
for cutting, the only qualifications needed being sufficient size and
transparency and good color. The almandite of Alaska shown in the
accompanying plate occurs in great quantities near the mouth of the
Stickeen River, but has not been extensively cut on account of its
being too opaque. Almandite usually occurs in metamorphic rocks, such
as gneisses or mica schists; also in granite. It is also found in many
gem gravels. From the ruby it can be distinguished, as can all
varieties of garnet, by its lower hardness and single refraction of
light. In artificial light, too, it borrows a yellow tint, rendering it
less pleasing, while the color of ruby grows more intense. When
almandite tends toward a brownish-red color it is known as vermeille.
Pyrope,
the magnesian variety of garnet, does not differ much in color from
almandite. Both are dark red, but while almandite tends toward a violet
tone, pyrope shades toward yellow. Pyrope is lighter than almandite,
the specific gravity being 3.7 to 3.8, while that of almandite is 4.1
to 4.3. It is also less easily fusible. It rarely occurs in crystals,
and where found in place is always associated with the
magnesium-bearing rocks, peridotite or serpentine. It is thus probably
always of eruptive origin. Pyrope is a characteristic constituent of
the diamond-bearing rock of South Africa, and is the stone known in
trade as " Cape ruby." These garnets afford excellent gems. "The home
of the pyrope, however, is, and has been for many centuries, Bohemia.
Here it is found in many localities, but chiefly in the northwestern
part, near Teplitz and Bilin. The garnets are found in a gravel or
conglomerate of Cretaceous age, resulting from the decomposition of a
serpentine. Sometimes, however, they are found in the matrix, and are
then often associated with a brown opal. They are found by digging and
separated by wash-
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