[Chemical composition] Since the radii of W and Mo ions are almost equal, W and Mo in the scheelite are completely homogeneous. It is a scheelite- molybdenum- tungsten series. At high temperatures, the Mo content is high; in the scheelite symbiotic with molybdenite, the Mo content is also high. Part of Ca can be replaced by Cu and TR. [Crystal structure] tetragonal system; [Form] Crystals are often tetragonal and biconical, and some are plated along {001} (Fig. H-22). According to (110) into a twin crystal is common. The aggregates are mostly irregularly granulated and less dense. Figure H-22 scheelite crystal [Physical properties] white, yellow, purple, etc., oil sheen or gloss adamantyl; transparent to translucent. The cleavage {111} is medium; the fracture is jagged. Hardness 4.5 to 5. The relative density is 5.8 to 6.2 (relative density decreases with increasing Mo). Crisp. It has a hair-rotation, and it emits light blue to yellow (depending on the content of Mo, Mo increases, and the fluorescence turns pale yellow to white) under ultraviolet light. [genesis and occurrence] is mainly produced in contact with metamorphic deposits. Also found in high-medium temperature hydrothermal deposits. [Main use] Important tungsten ore minerals. Inconel Powder,Nickel Powder,Pta Welding Ni Alloy Powder,Laser Cladding Ni Base Powder Luoyang Golden Egret Geotools Co., Ltd , https://www.xtccarbide.com
a 0 = 0.525 nm, c 0 = 1.140 nm; Z = 4. The scheelite crystal has a simple crystal structure and is formed by arranging a slightly flat [WO 4 ] tetrahedron and Ca ions along the c-axis.
Scheelite (also known as calcium tungstate)
Ca[WO 4 ]