s
Russian Gemstones Encyclopedia

Vladimir Bukanov. Russian Gemstones Encyclopedia

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

ADAMITE


ADAMITE (Adamin—Adamite—јдамин) (Friedel C., 1866), Named after the Fr. mineralogist Gilbert-Joseph Adam (1795-1881) who discovered the mineral at Chañarcillo, Chile.

Composition & Properties. Arsenate – Zn2[OH|AsO4], orthorhombic system. Hardness 3.5-4. Density 4.3-4.4. Glass luster. Fragile. Cleavage in one direction. Adamite is found in the shape of prismatic crystals forming grained crust and radial-rayed aggregates. Transparent to translucent. Color of bright green cuproadamite depends on the admixtures of copper, of violet to pink cobaltadamin – on the admixture of cobalt. Their are also honey-yellow, brown-yellow and, more rarely, colorless crystals.

Adamite is a mineral of the oxidation zone of ore deposits. In Russia, crystals of adamite and cuproadamite are found in the Primorskiy Region, at the Dal’negorskoye deposit. In East Transbaikalia they were found at the Doninskoye deposit, near the settlement of Kalga. In Kazakhstan, findings of adamite crystals up to 2 cm. long are known at the Gul’shad deposit, in the Balkhash Lake region. In Uzbekistan, crystals of cuproadamite were found at the Lachin Khana deposit, in the Ugamskiy Ridge. In other countries, well-formed crystals of adamite were discovered in France – at the Cap Garonne mine, Var Dépt. In Greece, gem-quality blue and green crystals were found at the Lavrion deposit; in Algeria – at the deposit near Guelma, Constantine Prov. In Namibia, adamite and cuproadamite available for faceting were discovered in significant quantities in the oxidation zone of the Tsumeb deposit, Otavi Mts. In Mexico, at the Ojuela mine, near Mapimí, Durango State, adamite in the form of bright violet crystals up to 6 cm. long, and in green to blue-green crystals to 2,5 cm was discovered in there. From that place they received faceted stones up to 4.83 ct. In Chile, fine crystals found at the Chañarcillo deposit, Atacama region.

Because of their bright color, massif, translucent aggregates and crystals of adamite are used as jewelry-ornamental material for cabochons. From transparent crystals they make faceted collection stones, usually not more than 3 ct.

Synonyms. Cupro-adamin, Germ. | Adamine | Petterdite, after the Engl. chemist W.F. Petterd.

Search