gems, turquoise,

This Stone has received its modern Name of Turchestay and Turquoise, from its being most commonly brought from Turkey into various Parts of Europe. De Boodt says, the Colour of this Gem is a Variegation of Green, White, and Blue; and that there are two Sorts of it, the oriental, from the East Indies and Persia, and the occidental, from Spain, Germany, Bohemia, Silesia, &c.; that in Persia, where it is found in greatest Plenty, it adheres to black Stones, as if it were an Excrement or a Transudation from them. A Stone of this sort is seldom found to exceed a Walnut in Size; and he mentions one in the Great Duke’s Museum, on which the Head of Julius Cæsar is engraved, as a very extraordinary Sample: He adds, That he never saw one bigger than an Hazel-nut; that some of the oriental ones have the Faculty of preserving their Colour perpetually, which are called Stones of the old Rock; and that others lose their Colour gradually, and are called of the new Rock. He then gives an Instance of a Turquoise which had lost its Colour upon being laid by some time after its Owner’s Death, which recover’d its beautiful Colour upon our Author’s wearing it upon his Finger in a Ring.