3l6 PRECIOUS STONES.
this stone are not abundant. The most notable are a figure
of Diana and another of the Empress Faustina, in the collection
of the Duke of Orleans ; one in Moscow, which formerly
belonged to Nadir Shah, inscribed with a sentence from the
Koran ; and one in the Florence collection. The best specimens, in the opinion of Mr. King, are the head of Augustus,
in the Pulsky collection, and a Gorgon's head, in the Fouid.
He says many of the ancient intagli and carnei cut on this
gem are of doubtful antiquity, on account of the perishable
nature of the material. A magnificent necklace composed of
twelve turquoises of a pale blue, engraved with the twelve
Cassars in relief, was sold at the beginning of the present century, for only one thousand eight hundred dollars.
Lapis-lazuli. — This mineral does not properly belong to
the family of precious stones, although it has been used from
very early times in jewelry and other decorations, and is supposed to be the sapphire of antiquity, which has been described
by the writers of those times as spotted with glittering particles or "shining with golden specks, like a serene sky adorned
with stars." Its name, lapis asul, from the Arabic, signifies
"blue stone."
Haüy considers this mineral identical with the lazulite of
mineralogists, but Dana classes them as distinct species,
differing in composition and specific gravity, though the precise constituents of the blue variety have not been ascertained
beyond a doubt. The lapis-lazuli is regarded by Church, not
as a definite mineral, but a mixture of a colorless and a blue
substance called haiiyne, spangled with minute yellow particles of iron pyrites. It is translucent to opaque, with a
hardness varying from five to six, and colors comprising azureblue, violet-blue, red and green with white or yellow spots, and
sometimes white ; it loses its beautiful azure by exposure to
