JADEITE. BURMA.
Jade,
so highly valued in China, has long been known to occur in Burma, and
much of that employed by the Chinese has been thence obtained. The
latest accounts of it are given in the Review of Mineral Production in
India for the years 1808 to 1003, by Dr. J. II. Holland. Director of
the Indian Geological Survey.a The industry is quite
extensive, being second only to the ruby mines in the gem-stone
production of India. Jade has usually been obtained from bowlders,
etc., but in upper Burma it is found in place and is systematically
quarried. The locality is in the Mogoung division of the Myltkylna
district, near Tanimaw, where the jade forms a light-colored layer in a
dark-green serpentine, which is apparently intrusive in sandstones of
Miocene age. Doctor Holland thinks that the jade "must have been
separated as a primary segregation from the magma,'' whence the
serpentine was derived.
Some fine material is also obtained from rolled pieces in the valley of the Uru River, an affluent of the Chiadwin.
The
product is taken into China, partly overland and partly via Rangoon,
and thence to the Straits Settlements and China. The trade is quite
important, and averaged annually from 1807 to 1003, inclusive, 3.014
hundredweights, valued at £44,770, an average price per hundredweight
of £11.44.
All
the Indian jade is jadeite, the soda-alumina variety, related to
pyroxene. The other variety, nephrite, a lime-magnesia member of the
amphibole group, is not known in India at all, or at least of any
valuable quality.
KUNZITE, BERYL, TOURMALINE. CALIFORNIA.
In
the report of this Bureau for 1003 ' a list was given of mines and
prospects on Hiriart Mountain, to the east of the Pala and Pala Chief
ridges, in which the gem minerals of the district—colored tourmalines,
kunzite, beryl, and their associates—were to some extent observed. In
the general outline of California gem mines, contained in the report
for 1004 r an account was given of later developments at
one of these mines—the Naylor-Vanderberg. Recent information describes
quite active work, with promising results, as having been carried on
during 1005 at several of these openings. It is highly interesting to
find there are now a number of adjacent localities yielding good
indications of the minerals that have already made the Pala region so
notable in American gem production, particularly of pink beryl and
kunzite, as well as of tourmaline and garnet.
The
Naylor-Vanderberg mine already noted has been penetrated by a tunnel
nearly 200 feet long, which cuts the main vein in the two mines. This
has revealed lithium beryl, kunzite, and a transparent green spodumene.
suggesting that found years ago in North Carolina. A rare
ferro-manganic phosphate of purple color also occurs here.
The
Hiriart mine has been opened by a tunnel for 80 feet; the ledge here
consists largely of albite with disseminated lepidolito. Tourmaline was
found and some lithium beryl, but no kunzite. The tourmalines were deep
grass green, aquamarine blue, and sometimes green with a pink or a
black center.
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