mines
have been worked systematically only of late years. Those of Chantaboon
are older than the Battambong mines. The crystals run larger than the
rubies, and, unlike the latter, are finer in the carat and larger sizes
than in the smaller.
Burmese
sapphires are found associated with rubies. The crystals are generally
larger, some weighing several hundred carats. The color is usually too
dark.
The
sapphires of Cashmere come principally from the Chinab valley of the
Himalayas, near the line of perpetual snow. They are found loose in
veins of disintegrated granite, together with tourmaline. They are
also found by the Lacha Pass. As far as known, they were first
discovered about 1880.
The
color of the Cashmere sapphires is a very clean blue, but it is usually
too light and often milky. Even in the finer stones thin white streaks
frequently traverse the stone with the grain, giving an appearance of
alternate shafts of light and blue shadows. When the stone is free from
these common defects, and the color is deep, it is the finest of all
sapphires.
In
Ceylon the sapphires are found under much the same conditions as
rubies. Much of the corundum is too poor for use as jewels, being
coarse and impure. The transparent stones are usually pale, some being
colorless. Many are particolored, others yellow. With them are found
rolled pieces of spinel, chrysoberyl, zircon, tourmaline, and quartz.
The best are found in the old river gravels.
Sapphires
are found in many parts of Australia, but they are of more interest to
the mineralogist than to the jeweller, as they cut too dense and black
to be desirable as jewels. Occasionally a piece of fine color can be
obtained from the edge of a crystal. A bronze-colored variety is
notable for its high specific gravity, some being, according to Mr.
Streeter, as high as 4.4. They are found in the tin-drifts and
gold-fields.
