Mawe says the carnelian, onyx, agate, etc., could not be engraved by any stone except the diamond. This is an error,
since they have been cut by the corundum·, and, according to
some writers, by copper tools tempered to excessive hardness,
an art not understood at the present time. It is a question
with some antiquaries whether the diamond was known to the
ancient Mexicans, yet they engraved on hard stones.
Gnostic gems. — The Gnostics combined both pagan and
Christian ideas in their system, which has been very fully
represented on engraved gems, and as Alexandria was the
nursery of Gnosticism, the larger part of what are called
Gnostic gems are of Egyptian origin.
The worship of the Egyptian god Abraxas, and the Persian
god, Mithras, — both representing Phcebus, or the sun-god, —
was introduced into this system, hence the title Abraxas has
been applied to the entire class of Gnostic gems.
Abraxas, thought to be identical with Serapis, combines
various attributes and is represented with the head of a cock or
a lion, a human body, and legs composed of serpents. He bears
the scourge, the royal emblem of Egypt, and a shield, and was
lord of all inferior spirits. The letters when employed as
Greek numerals make the number three hundred and sixty-five,
