[Chemical composition] The molybdenite composition in nature is almost close to the theoretical value. Re is an important class of similar substances, and can be up to 2%. S can be replaced by Se and Te up to 25%. [Crystal structure] hexagonal system (2 H ); Figure L-22 Molybdenum ore crystal structure (quoted from Pan Zhaoyu et al., 1993) The crystals of molybdenite have a layered structure (Fig. L-22). In the structure, the surface network composed of Mo 4+ is sandwiched between the upper and lower meshes composed of S 2 - , which together form a three-column coordination structure layer, and [MoS 6 ] constitutes a triangular prism-shaped coordination polyhedron, and this structure The layers are connected by an S2 - up composed of an empty octahedron layer. The intra-layer ions are tightly connected, and the attraction between the layers is very weak. Therefore, the parallel {0001} development is completely cleavable, and the crystals are flaky and plate-like. [Formation] The single crystal is a hexagonal plate shape or a sheet shape, and is usually produced in a sheet-like or scaly aggregate (Fig. L-23). Figure L-23 Scale-like molybdenite crystal aggregate [Physical properties] leaden; streak light gray and on the vitreous enamel plate as greenish gray black; metallic luster, opacity. The cleavage parallel {0001} is extremely complete and the cleavage sheet is flexible. Hardness 1. The relative density is 5.0. Have a slippery feel. [genesis and occurrence] is mainly produced in high and medium temperature hydrothermal deposits. China's molybdenum reserves rank first in the world, the most famous producing areas are Liaoning, Henan, Shanxi, Shaanxi and so on. [Qualification characteristics] Lead gray, metallic luster, low hardness, a group of extremely complete cleavage. Its relatively high density, strong gloss, light color and streaks, and yellow-green streaks with characteristics on glazed porcelain plates can be distinguished from similar graphite . [Main use] It is the most important ore mineral of molybdenum, and it is also the main ore for extracting Re. When there are many Pt group elements (Os, Pd, Rn, Pl), it can be comprehensively utilized. Smart Door Lock Part,Intelligent Door Lock Motor Accessories,Smart Door Lock Accessories,Intelligent Door Lock External Accessories Dongguan Shangjie Precision Hardware Co., Ltd , https://www.shangjiecnc.com
; a 0 = 0.315 nm, c 0 = 1.230 nm; Z = 2.
Molybdenite
MoS 2