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cobalt

cobalt (symbol Co) Metallic element, a transition metal, discovered c.1735. It is found in cobaltite and smaltite, but mostly obtained as a by-product during the processing of other ores. Cobalt is a constituent of vitamin B12. It is used in high-temperature steel, artists' colours (cobalt blue), jet engine manufacture, cutting tools and magnets. Cobalt-60 (half-life 5.26yr) is an artificial isotope used as a source of gamma rays in radiotherapy and tracer studies. Properties: at.no. 27; r.a.m. 58.9332; r.d. 8.9; m.p. 1495°C (2723°F); b.p. 2870°C (5198°F); most common isotope Co59 (100%).

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cobaltite

cobaltite (cobalt glance) Mineral, CoAsS; sp. gr. 6.0–6.5; hardness 5–6; cubic; from white to dark grey or greyish-black, all with a reddish tinge; grey–black streak; metallic lustre; crystals octahedra, cubes, and pentagonal-dodecahedra, also occurs massive, and in irregular grains; cleavage perfect cubic; occurs mainly in hydrothermal veins and contact metamorphic zones, and is associated with chalcopyrite, sphalerite, chlorite, tourmaline, and apatite. It is one of the principal ore minerals for cobalt.

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"cobaltite." A Dictionary of Earth Sciences. . Encyclopedia.com. 24 May. 2017 <http://www.encyclopedia.com>.

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"cobaltite." A Dictionary of Earth Sciences. . Retrieved May 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/cobaltite

cobaltite

cobaltite (kō´bôltīt, kōbôl´tīt), opaque, silver-white, sometimes reddish or grayish mineral of the pyrite group, a compound of cobalt, arsenic, and sulfur, CoAsS. It occurs in crystals of the cubic system, also in compact to granular masses. It is an important ore of cobalt, found chiefly in Sweden, Norway, India, and Azerbaijan.

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"cobaltite." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 24 May. 2017 <http://www.encyclopedia.com>.

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"cobaltite." The Columbia Encyclopedia, 6th ed.. . Retrieved May 24, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/cobaltite