always been by far the most valuable gem-mineral resource of the United States.
An exceedingly beautiful and interesting variation in gems is the star sapphire and star ruby. These
are very valuable when the star marking is well defined and shows a
fine, six-pointed star, which is always more clearly defined when seen
under an artificial light. "Star sapphires" and rubies are always cut
cabochon, with the center of the star at the apex of the cabochon. What
causes the formation of the star is not definitely known, but it is
probably due to the presence of a foreign substance in the sapphire or
ruby.
In
history both these gems are of great interest. Rubies are mentioned in
the Bible in the Proverbs and in the Book of Job. The Greeks and Romans
ascribe to the ruby the power of emitting light in darkness; the Hindus
describe the abodes of their gods as being lighted with rubies.
Sapphires
were also known in ancient times, which is attested by the fact that
the word sapphire is nearly the same in all languages.
The gem was believed to be a destroyer of poison and a powerful charm, protecting the wearer from fever.
Dr. O. C. Farrington states that "Burton, the
