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GEMS.
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It
is certain that the Count of Rabassommè, who was the happy possessor of
this wonder, asked 200,000 lire for it, trusting perhaps a little too
much to the credulity of the simple.
LIV.
LAPIS LAZULI, OR LAZULITE.
The name of this mineral comes from the Arabic azul, which signifies heaven, and refers to its colour.
This substance was known to the ancient Romans under the name of sapphirus, the word with which we designate the blue corundum.
That particular kind of it which exhibits pyrites of iron in its mass was called gapphirus regilus.
Pliny gave the name of cyanus to a stone which some modern authors thought to be lapis lazuli, but from his description does not appear to be such.
Lapis
lazuli is sufficiently hard to cut glass, heavy, opaque, of a blue more
or less bright, often covered with brilliant ferruginous pyrites, of a
close texture, and capable of receiving a bright polish. It is
translucent at the edges when thinned, and breaks into vitreous
fragments ; it is often found crystallized in the regular form of the
oblique prism, having four faces ; it is in folds, and has a specific
gravity which varies between 2-7675 and 2-9454.
A triple analysis gave the following results, which present a very striking difference :
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