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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

BERYLLONITE


BERYLLONITE (Beryllonit—Béryllonite—Ѕериллонит) (Dana, E.S., 1888). The name reflects its beryllium content. Phosphate – NaBe[PO4] monoclinic system. Hardness 5.5-6. Density 2.8. Glass luster, nacre one on the cleavage planes. Cleavage in two directions. Fragile. Beryllonite is a rare mineral forming short-columnar or table crystals and grained masses. Color: colorless, white and pale yellow. Transparent to translucent. It looks like rosterite, it is found in granite pegmatites. Beryllonite was discovered first of all in the U.S.A., in Maine State, near Stoneham, Oxford Co. They found its large crystals there. From them faceted stones up to 24.96 ct. were made. In Zimbabwe, beryllonite is extracted at the Sleim mine, near Urungwe Dist., ~ 200 km to northwest of Harare. In Afghanistan, it was found at the Paprok deposit, Kunar Prov. Its white crystals to 10 cm. long display the effect of cat’s-eye in cabochon. In India, in the Jammu and Kashmir State (disputed area) beryllonite in crystals up to 4 cm. was found at the Niet deposit in the valley of the Shigar River; and also near Shengus, in the region of Gilgit. They extracted its gem-quality crystals up to 18 m. long there. Besides, findings of transparent crystals of beryllonite were registered in Finland, at the Viitaniemi deposit, near Eriyarvi; and in Germany, near Hannover, Lower Saxony; and also in Brazil.

Beryllonite is available for faceting, however, it has mainly collection significance because of its rarity. In the Smiths. Inst., Wash., there are several faceted stones from Maine State with the mass: 2.5; 3.3; 3.9 and 5.1 ct.

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