Philadelphia in 1876. Some of the mineral collections in the
United States contain crystals of very large size.
Fine specimens found at Lake George and other places in
New York, of great brilliancy, and sometimes with both ends of
the crystal terminating in natural facets, are sold as " Lake
George diamonds " ; but even these " diamonds " are frequently
counterfeited by glass and pastes. Quartz, occurring in the
form of rolled pebbles, in New Jersey, Colorado, and Arkansas,
affords a quality suitable for gems. The crystal employed for
optical purposes in this country is almost entirely brought
from Brazil — more on account of its cheapness, it has been
said, than for any superiority over the native production.
Ametliyst. —This name, when applied to a gem, is an epithet
to denote color, and is given to varieties of other species, and
sometimes to all stones of a purple hue. The term is from a
word meaning " without intoxication," originally given to a
kind of grape supposed to be free from any inebriating quality,
and, by a figure of speech, applied to the substance holding the wine ; hence it was considered the most suitable for
drinking-cups, on account of its being a protection against
intoxication. Its beautiful color, thought to be due to manganese, iron, and perhaps soda, can be dispelled by heat, a
fact which has enabled lapidaries to secure uniformity of tint.
The deep shades are less brilliant, and for this reason the
artists of antiquity preferred the lighter colored specimens.
Some antiquaries have believed the amethyst identical with
the hyacinth of Pliny, while others have supposed the antique
hyacinth was the same as modern sapphire. The oriental amethyst, a variety of the corundum, an exceedingly rare and
beautiful gem, is distinguished from the quartz amethyst by its
deep shade of violet without the reddish tint of the latter.
On account of its fine color, play of light, and capacity for