Reverting
to the Chrysolite, this was said of old to " cool boiling water, and
assuage wrath." The stone is named Peridot when of a deep olive-green ;
" Olivine " when of a deep yellowish-green ; and " Chrysolite " when of
a lighter, or greenish-yellow colour. Its most ancient title was
Tharshish ; and from its " signature" it was judged to be of a solary
nature.
Imitation
Turquoises are now made with the same chemical composition as the
natural stone. So as to discriminate between these, if a splinter of
the stone to be tested is heated in a platinum capsule, the true
Turquoise will be reduced to a brownish-black powder, with a
decrepitating sound; but the false Turquoise does not thus decrepitate
; it fuses to a glass, or is reduced to a frit.
