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quality
suitable for cutting are found, they are either laid aside to sell to
caravans which come to the mines for this purpose from China, or are
turned over to native artisans, who reduce them to desired shapes by
sawing them with steel wire strung on a bamboo bow. The jadeite from
this locality is commercially distributed all over China, where it is
held in high esteem, and commands a high price. Bauer states that he
saw a piece containing less than three cubic feet which was valued at
$50,000. The jadeite of milk-white color is that most highly esteemed,
although that with bright green spots is also considered of superior
value.
Nephrite
is a variety of amphibole much resembling jadeite in color, hardness,
and texture. It is, however, of somewhat lower specific gravity than
jadeite, ranging as it does from 2.96 to 3.1, and it fuses with much
greater difficulty. Under the microscope a section shows a finely
fibrous character differing from that of the broad fibers or granules
of jadeite, and the optical characters throughout are those of an
amphibole rather than of a pyroxene. In composition nephrite is a
silicate of calcium and magnesium, having the theoretical percentages,
silica 57.7, magnesia 28.9, and lime 13.4. A little alumina, iron, and
soda are often found combined with the above. Nephrite has the
glistening luster and semi-translu-cency of jadeite, and like that
mineral breaks with a splintery fracture. It is not attacked by acids.
It does not occur in distinct crystals.
i>The
most important locality for nephrite at the present time is Turkestan,
where it occurs in the Karakash Valley in the Kuen Lun Mountains, and
at other points in the same range. In these localities it forms layers
in gneiss and amphibole schists. It is very pure and translucent. Some
of the mines have been worked for over two thousand years. //Nephrite
of excellent quality also occurs in eastern Siberia in the beds of the
Onot and Chara Jalga rivers. It occurs here as boulders, one of which
is described as being twelve feet in length and three feet in width; it
is also found in place. A canopy thirteen feet in height has been made
for the tombs of the present Czar and Czarina of Russia of nephrite
from this locality.
In
New Zealand nephrite occurs in seve^l localities on the west coast of
South Island, and is used extensively by the Maoris for fashioning into
weapons and ornaments.
Boulders
of nephrite have also been found in river beds in Alaska. In several
river beds of Europe nephrite is found as pebbles, and it occurs in
place in the Zabten Mountains in Silesia, but none of these localities
affords an important source of supply.
Jade,
including both jadeite and nephrite, though still highly prized by the
Chinese and other peoples of Asia, is little used by Europeans at
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