beryl

Several varieties of the mineral beryl are valued as gemstones: aquamarine (pale blue-green); emerald (deep green); heliodor (golden yellow); and morganite (pink). Beryl consists of a silicate of beryllium and aluminum of great hardness, and is a commercial source of beryllium. Before 1925 beryl was used only as a gemstone, but since then many important uses have been found for beryllium (in nuclear reactors, space vehicles, and X-ray tubes). No large deposits have been found, and most production is a by-product of the mining of feldspar and mica. Brazil is a major producer; others producers include Zimbabwe, South Africa, Namibia, and the USA.