From time immemorial this material has been rudely mined by the
Indians. Their method is to pour cold water on the rocks after
previously heating them by fires built against them. This process
generally deteriorates the color of the stone to some extent, tending
to change it to a green. The Indians barter turquoise with the Navajo,
Apache, Zuni, San Felipe, and other New Mexican tribes for their
baskets, blankets, silver ornaments, and ponies.

_Garnet and Olivine (Peridot)._--The finest garnets and nearly all the
peridots found in the United States are obtained in the Navajo Nation,
in the northwestern part of New Mexico and the northeastern part of
Arizona, where they are collected from ant hills and scorpion nests by
Indians and by the soldiers stationed at adjacent forts. Generally
these gems are traded for stores to the Indians at Gallup, Fort
Defiance, Fort Wingate, etc., who in turn send them to large cities in
the East in parcels weighing from half an ounce to thirty or forty
pounds each. These garnets, which are locally known as Arizona and New
Mexico rubies, are the finest in the world, rivaling those from the
Cape of Good Hope. Fine gems weighing from two to three carats each
and upward when cut are not uncommon. The peridots found associated
with garnets are generally four or five times as large, and from their
pitted and irregular appearance have been called "Job's tears." They
can be cut into gems weighing three to four carats each, but do not
approach those from the Levant either in size or color.

_Gold Quartz._--Since the discovery of gold in California, compact
gold quartz has been extensively used in the manufacture of jewelry,
at one time to the amount of $100,000 per annum. At present, however,
the demand has so much decreased that only from five to ten thousand
dollars' worth is annually used for this purpose.

In addition to the minerals used for cabinet specimens, etc., there is
a great demand for making clocks, inkstands, and other objects.

_Quartz._--During the year 1887 about half a ton of rock crystal, in
pieces weighing from a few pounds up to one hundred pounds each, was
found in decomposing granite in Chestnut Hill township, Ashe County,
North Carolina. One mass of twenty and one-half pounds was absolutely
pellucid, and more or less of the material was used for art purposes.
This lot of crystal was valued at $1,000.

In Arkansas, especially in Garland and Montgomery Counties, rock