in Chihuahua, Mexico; in Honolulu, New South Wales; and in Broken Hill, Australia.
Emerald: A
green variety of Beryl. This is a striking example of a gem which owes
its beauty of color to an impurity, the fine green color so desirable
in this stone being entirely due to a small amount of chromium.
Flawless Emeralds are extremely rare and it is this rarity of
desirable stones of the first quality, which makes the Emerald one of
the most costly of precious stones. The value of the best gems is three
or four times that of Diamonds of equal weight. The finest Emeralds are
found in geodes and embedded in clay slate at the Muso Mine, Colombia,
New Granada. They also occur near the Red Sea, in Tyrol, New South
Wales, Brazil and Ceylon
Emery: A
massive, granular, impure Corundum, or mixture of Corundum with
Magnetite, and other minerals. It feels and looks like a fine grained
iron ore, which it was long considered to be. It is used extensively as
an abrasive.
Enargite: Sulpharsenate
of Copper. A minor ore of copper, containing Copper 48%, Arsenic 19%,
Sulphur 33%. It also usually contains a little antimony and zinc and
sometimes silver. It occurs in Peru, Chile, Colombia and Mexico; in the
United States in Missouri, Colorado, Utah, Montana and California. It
is smelted as an ore of copper and furnishes for the market, arsenic
oxide.
Epidote: A
Silicate of Aluminium, Lime and Oxide of Iron or Manganese. A mineral
of a yellowish-green, pistachio-green, dark green, brown or, rarely,
red color. It is a semi-precious mineral, but iarely cut owing to the
fact that gem material of sufficient transparency is not easily
obtained. It is found in Austria, Tyrol, Switzerland, Italy, Norway,
Japan and many places in North America.
Epsomite: Hydrous
Magnesium Sulphate; Epsom Salts, when occurring native. Occurs in
crystals, in masses, and delicately fibrous crusts, with color and
streak white, and taste bitter and saline. It occurs in Epsom, England;
in Bohemia, Spain, Chile and South Africa. In the Mammoth Cave,
Kentucky, it adheres to the roof in loose masses like snow-balls.
Erinite: An
emerald-green Arsenate of Copper, found in Ireland. Occurs in
mammillated crystalline groups, subtranslucent to nearly opaque.
Contains 60% Cupric Oxide.
