Molybdenum


Molybdenum (Mo) is a refractory metal that is obtained primarily by processing the mineral molybdenite (MoS2). Molybdenite is soft, lead gray, has a metallic luster, a greasy feel, and produces a greenish streak when rubbed on unglazed porcelain. Molybdenite is an effective dry solid lubricant. Elemental molybdenum is a hard gray metal with a relatively high melting point (4,730° F.) and a high specific gravity (10.2). Molybdenum (moly) is used primarily as an alloying agent in iron and steel, where it enhances hardenability, strength, toughness, and resistance to wear and corrosion. Steels containing molybdenum are used in the transportation industry and as drill steel in deep oil and gas wells. Molybdenum is also used as a metal in numerous chemical applications, including fire retardants, catalysts, and pigments.

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Molybdenum crystal

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Pyrite, Hot Spring County


Molybdenite was identified at Magnet Cove in Hot Spring County in 1939, where it is present in veins in a fractured igneous rock. The veins are composed mainly of orthoclase feldspar and pyrite, with minor amounts of quartz, fluorapatite, plagioclase feldspar, molybdenite, and brookite, and range in thickness from less than 0.5 inch to 5 feet. The Mo-Ti prospect, as this site was named, was explored by geophysical methods, trenching, and drilling. Molybdenum mineralization occurs in Baxter County where the lead molybdate -- wulfenite, is reported to be associated with galena, cerussite, and quartz. No molybdenum ore has been mined in Arkansas.


References

Erickson, R. L., and Blade, L. V., 1963, Geochemistry and petrology of the alkalic igneous complex at Magnet Cove, Arkansas: U. S. Geological Survey Professional Paper 425, 99 p.

Holbrook, D. F., 1948, Molybdenum in Magnet Cove, Arkansas: Arkansas Resources and Development Commission, Division of Geology Bulletin 12, 16 p.

McKnight, E. T., 1935, Zinc and lead deposits of northern Arkansas: U. S. Geological Survey Bulletin 853, 311 p.

Image courtesy of Stas1995 from https://commons.wikimedia.org/wiki/File:Pure_molybdenum_crystal,_about_20_grams.jpg