ral species, do not seem to occur together. The darker
bottle-green specimens come from the Island of St. John in the Red Sea.
It is said that many of the finer peridots now available have been recut
from old stones mined many years ago.

Queensland supplies light-green chrysolite, and Arizona a
yellowish-green variety. Light-green stones have been found near the
ruby mines of Upper Burmah.

MOONSTONE. Moonstone comes mainly from Ceylon. The native cut specimens
are sent here and recut, as, when native cut, the direction of the grain
is seldom correct to produce the moonlight effect in symmetrical
fashion. The native cutters apparently try to retain all the size and
weight that is possible, regardless of the effect.

TURQUOISE. Turquoise of the finest blue and most compact texture (and
hence least subject to color change) comes from the province of Khorasan
in Persia. Several of our western states supply turquoise of fair
quality, notably New Mexico, Arizona, Nevada, and California.

LAPIS LAZULI. Lapis Lazuli comes from Afghanistan, from Siberia, and
from South America.

MALACHITE. Malachite is found in many copper mines, but principally in
those of the Ural Mountains.

AZURITE. Azurite is found in the Arizona mines and in Chessy, in France
(hence the name chessylite, sometimes used instead of azurite).

* * * * *

REFERENCES. Students who wish to get a fuller account of the occurrence
of precious stones should run through G. F. Herbert-Smith's _Gem-Stones_
under the different varieties. This work is the most recent authentic
work of a strictly scientific character. Dr. George F. Kunz's _Gems and
Precious Stones of North America_ gives a detailed account of all the
finds in North America up to the time of publication. Many of these are
of course of little commercial importance. The _Mineral Resources of the
United States_ contains annually a long account of the occurrences of
gem materials in this country. A separate pamphlet containing only the
gem portion can be had gratis from the office of the United States
Geological Survey, Washington, D. C.

LESSON XXII

HOW ROUGH PRECIOUS STONES ARE CUT

ROUGH PRECIOUS STONES. John Ruskin, who had the means to acquire some
very fine natural specimens of gem material was of the opinion that man
ought not to tamper with the wonderful crystals of nature, but that
rather they should be admired in the rough. While one can understan