mineral formations that contain beryllium in quantities such that its extraction is feasible at modern technical and economic levels. Beryllium is found in the ores mainly in the form of the minerals themselves, as well as in the form of an isomorphic impurity (usually not more than 5–10 percent) in rock-forming minerals. The chief beryllium minerals that make up ores are beryl (which contains 10–12 percent BeO), phenakite (42–45 percent), bertrandite (40–42 percent), helbertrandite (32–35 percent), chrysoberyl (18–20 percent), helvite and genthelvite (10–12 percent). The minor beryllium minerals are bavenite (6–7 percent BeO), euclase (16–20 percent), beryllium-containing margante (1–3 percent), and leucophanite (10–12 percent). The beryllium minerals are extracted from ores manually as well as by concentration from finely disseminated ores—chiefly by flotation—obtaining standard concentrates with 10, 8, and 5 percent BeO.
Deposits of beryllium ore are endogenic. Their appearance is associated with regions of propagation of granite and sub-alkaline granitoid massifs; they are formed during postmag-matic processes. The following industrial-genetic types of deposits are distinguished: (1) beryllium-containing granite pegmatites, with an average BeO content of 0.05–0.09 percent; (2) helvitic and chrysoberylic skarns, which are characterized by significant scales and low BeO content (0.1–0.15 percent); (3) phenakite-genthelvitic alkaline metasomatites, represented by zones of microclinization in ancient granites and gneisses (0.3–0.55 percent); (4) beryllium-containing greisens and quartz-lode formations (0.1–0.15 percent); (5) beryllium-containing fluorite-micaceous metasomatites, represented by mineralized zones of granulation in various sedimentary-metamorphic rocks (0.1–0.16 percent); (6) bertrandite-phenakite-containing fluorite metasomatites in limestones in contact with small cupolas of granites or granosyenites, the richest type of ore (0.2–1.5 percent); and (7) helbertrandite-containing converted rhyolites (0.7 percent BeO). In the USSR berylliumore deposits of almost all the types listed are known. Abroad, deposits of beryllium ore are concentrated in the USA (the states of Utah, Colorado, Nevada, and South Dakota), Brazil, Argentina, Mexico, the Republic of South Africa, South West Africa (Namibia), Mozambique, southern Rhodesia, Uganda, the Malagasy Republic, and India.
REFERENCESNekotorye tipy pnevmatolito-gidrotermal’nykh mestorozhdenii berilliia. Moscow, 1959.
Beus, A. A. Geokhimiia berilliia i geneticheskie tipy berillievykh mestorozhdenii. Moscow, 1960.
Moskevich, M. M. Mineral’no-syr’evye resursy, proizvodstvo i potreblenie berilliia, litiia, niobiia i tantala ν kapitalisticheskikh stranakh. Moscow, 1966.
A. I. GINZBURG