CHRYSOPRASE (Gr. Xpvvor,

See also:

• GOLD
• GOLD [symbol Au, atomic weight 195.7(H = 1),197.2(0 =16)]

gold, and apaorov,

See also:

• LEEK

leek)  , a name applied by modern mineralogists to an apple-green variety of chalcedony or hornstone, used as an ornamental stone . The colour is due to the presence of nickel, probably in the form of a hydrous silicate . By exposure to a moderate heat, or to strong light, the chrysoprase becomes paler, or even colourless, but it may regain its colour by absorption of moisture . Chrysoprase is a mineral of rather limited distribution . Most of it comes from the neighbourhood of Frankenstein in Silesia, where it occurs in association with altered serpentine . It is found to a limited extent at Revdinsk, near Ekaterinburg, in the Urals; and it occurs also in India . It is known, too, at several localities in North America, notably at Nickel Mount, Douglas county, Oregon, where it occurs in nickeliferous serpentine . The chrysoprase of the moderns is certainly not the chrysoprasius of Pliny, or the Xpvalnrpaaos of Greek writers . The ancient stone was not improbably our chrysoberyl, and it is doubtful whether the modern chrysoprase was known until a comparatively late period . The chrysoprase of Kosemutz, near Frankenstein in Silesia, was discovered in 1740, and used by Frederick the Great in the decoration of the palace of Sans Souci at Potsdam . But at a much earlier date the Silesian chrysoprase was used for mural decoration at the Wenzel chapel at Prague . Chrysoprase was a favourite stone in England at the beginning of the 19th century, being set round with small brilliants and used for brooches and rings .

At the

present time it is said to be regarded by some as a " lucky stone." Much commercial chrysoprase is chalcedony artificially stained by impregnation with a green salt of nickel . (F . W .