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Scheelite is a calcium tungstate mineral with the chemical formula CaWO₄. It is an important oreAn ore is a mineral deposit containing a metal or other valuable resource in economically viable concentrations. Usually, it is used in the context of a mineral deposit from which it is economical to extract its metallic component. Ores are mined. Ore bod of tungsten. Well-formed crystalThis article is about the form of solid matter. For other uses of this word, see Crystal (disambiguation . Insulin Crystals A crystal is a solid in which the constituent atoms, molecules, or ions are packed in a regularly ordered, repeating pattern extends are sought by collectors and are occasionally fastened into gemstones when suitably free of flaws. Scheelite has been synthesized via the Czochralski process; the material produced may be used to imitate diamond, as a scintillator, or as a solid state lasing medium.

Its crystals are in the tetragonal crystal system, appearing as dipyramidal pseudo-octahedra. Colors include golden yellow, brownish green to dark brown, pinkish to reddish gray, and colorless. Transparency ranges from translucent to transparent and crystal faces are highly lustrous (vitreous to adamantine). Scheelite possesses distinct cleavage and its fracture may be subconchoidal to uneven. Its specific gravity is high at 5.9 - 6.1 and its hardness is low at 4.5 - 5. Aside from pseudo-octahedra, scheelite may be columnar, granular, tabular or massive in habit. Twinning is also commonly observed and crystal faces may be striated. Scheelite streaks white and is brittle.

Gems cut from transparent material are fragile yet attractive: Scheelite's refractive index (1.918-1.937 uniaxial positive, with a maximum birefringence of 0.016) and dispersion (0.026) are both moderately high. These factors combine to result in scheelite's high lustre and perceptible "fire", approaching that of diamond. Owing to low hardness, however, cut scheelites are best enjoyed unset as valuable collector's pieces.

Scheelite is associated with wolframite in placer deposits and forms in pegmatites, hydrothermal veins, and areas of contact metamorphism. Other associated minerals include fluorite, muscovite, dolomite and molybdenite. Its type locality is the Bisperg iron mine in Säter, Dalecarlia, Sweden. Officially recognized in 1821, scheelite was named after Swedish chemist Carl Wilhelm Scheele, the discoverer of tungsten.

Crystals exceeding 0.5 kilograms (1 pound) have been found in Brazil: Other notable localities include Australia, Austria, Bolivia, Burma, England, Finland, France, Italy, Japan, Sri Lanka, Switzerland and the United States. The Sichuan Province of China has emerged as a newly important source with many "gemmy" specimens recovered. Fine crystals are also found in Tong Wha , Korea.