scheelite

scheelite , heavy white or yellow mineral, calcium tungstate, CaWO ₄ , crystallizing in the tetragonal system. It is found in granite pegmatites, in contact-metamorphic deposits (especially limestones intruded by granites), and in quartz veins. It is an important ore of tungsten and is mined in many parts of the world. Scheelite fluoresces bright bluish-white in ultraviolet radiation, a distinguishing feature utilized in prospecting and mining.

scheelite Mineral, CaWO₄; sp. gr. 5.9–6.1; hardness 4.5–5.0; tetragonal; white, or sometimes shades of yellow, green, brown, or red; white streak; vitreous lustre; crystals usually bipyramidal, also occurs massive or granular; cleavage good {111}; fluorescent; occurs in pegmatite veins and high-temperature mineral veins, often in association with wolframite, cassiterite, molybdenite, fluorite, and topaz, also in contact metamorphic zones together with axinite, garnet, wollastonite, and metamorphic calcium minerals. It is one of the chief ores of tungsten, and named after the 18th-century Swedish chemist K. W. Scheele.