Molybdenite

Molybdenite
Molybdenite

Euhedral molybdenite on quartz, Molly Hill mine, Quebec, Canada. The large crystal is 15mm across
General
Category Sulfide mineral
Chemical formula MoS2
Strunz classification 02.EA.30
Identification
Color Black, lead-silvery gray
Crystal habit Thin, platy hexagonal crystals terminated by pinacoidal faces, also as tapering six-sided pyramids that can be truncated by the pinacoids. Also massive, lamellar and in small grains in sulfide ore bodies
Crystal system Hexagonal; 6/m 2/m 2/m
Cleavage [0001] Perfect
Fracture flaky
Mohs scale hardness 1 - 1.5
Luster Metallic
Streak bluish - gray
Diaphaneity Opaque
Specific gravity 4.73
Fusibility Infusible (1185 °C decomp)
Other characteristics Thin cleavage sheets and crystals are flexible, but not elastic. It has a greasy feel and leaves marks on fingers

Molybdenite is a mineral of molybdenum disulfide, MoS2. Similar in appearance and feel to graphite, molybdenite has a lubricating effect that is a consequence of its layered structure. The atomic structure consists of a sheet of molybdenum atoms sandwiched between sheets of sulfur atoms. The Mo-S bonds are strong, but the interaction between the sulfur atoms at the top and bottom of separate sandwich-like tri-layers is weak, resulting in easy slippage as well as cleavage planes.

Crystal structure of molybdenite
A sample of molybdenite mineral less pure than the single-crystal specimen at right.

Molybdenite occurs in high temperature hydrothermal ore deposits. Its associated minerals include pyrite, chalcopyrite, quartz, anhydrite, fluorite, and scheelite. Important deposits include the disseminated porphyry molybdenum deposits at Questa, New Mexico and the Henderson and Climax mines in Colorado. Molybdenite also occurs in porphyry copper deposits of Arizona, Utah, and Mexico.

The element rhenium is always present in molybdenite as a substitute for molybdenum, usually in the parts per million (ppm) range, but often up to 1–2%. High rhenium content results in a structural variety detectable by X-ray diffraction techniques. Molybdenite ores are essentially the only source for rhenium. The presence of the radioactive isotope rhenium-187 and its daughter isotope osmium-187 provides a useful geochronologic dating technique.

Semiconductor

Molybdenite flakes are a direct bandgap semiconductor with good charge mobility and can be used to create small or low-voltage transistors[1] possibly easier than graphene.

See also

References and external links

  1. ^ "Molybdenite transistor is a first". 8 Feb 2011. http://physicsworld.com/cws/article/news/45056. 

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Look at other dictionaries:

  • Molybdénite — Catégorie II : sulfures et sulfosels[1] Molybdénite sur quartz La Motte (Québec) …   Wikipédia en Français

  • Molybdenite — Molybdénite Molybdénite CatégorieII : sulfures et sulfosels Molybdenite sur quartz – Lamothe Quebec (5,5x3cm) Général …   Wikipédia en Français

  • molybdénite — [ mɔlibdenit ] n. f. • 1807; de molybdène ♦ Minér. Principal minerai du molybdène, sulfure naturel (MoS2). ● molybdénite nom féminin Sulfure naturel de molybdène hexagonal, à l éclat métallique et au toucher gras. molybdénite [mɔlibdenit] n. f.… …   Encyclopédie Universelle

  • Molybdenite — Mo*lyb de*nite, n. [Cf. F. molybd[ e]nite. See {Molybdena}.] (Min.) A mineral occurring in soft, lead gray, foliated masses or scales, resembling graphite; sulphide of molybdenum. [1913 Webster] …   The Collaborative International Dictionary of English

  • molybdénite — molybdénite, (mo li bdé ni t ) s. f. Terme de minéralogie. Sulfure de molybdène natif …   Dictionnaire de la Langue Française d'Émile Littré

  • molybdenite — [mə lib′də nīt΄] n. a very soft, lead gray mineral, MoS2, the chief ore of molybdenum; molybdenum sulfide …   English World dictionary

  • molybdenite — /meuh lib deuh nuyt /, n. a soft, graphitelike mineral, molybdenum sulfide, MoS2, occurring in foliated masses or scales: the principal ore of molybdenum. [1790 1800; obs. molybden(a) MOLYBDENUM + ITE1] * * * ▪ mineral  the most important mineral …   Universalium

  • molybdenite — molibdenitas statusas T sritis chemija apibrėžtis Mineralas. formulė MoS₂ atitikmenys: angl. molybdenite rus. молибденит …   Chemijos terminų aiškinamasis žodynas

  • molybdenite — noun Etymology: New Latin molybdena Date: 1837 a metallic gray usually foliated mineral consisting of molybdenum disulfide that is a major ore of molybdenum …   New Collegiate Dictionary

  • molybdenite — noun A mineral, molybdenum disulfide MoS, that is the principal ore of molybdenum; it is structurally similar to graphite and has a similar look and feel …   Wiktionary

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