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.
	By way of summarizing the set of arguments, and considerations, now advanced, so as to determine what fundamental constituents, of a character calculated to affect the bodily welfare, each Precious Stone individually possesses, the entire system of such stones can be first broadly classified; through doing which the distinctive salutary, or noxious components of the several Precious Stones in each class will be more readily understood.