Colemanite


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colemanite

[′kōl·mə‚nīt]
(mineralogy)
Ca2B6O11·5H2O A colorless or white hydrated borate mineral that crystallizes in the monoclinic system and occurs in massive crystals or as nodules in clay.

Colemanite

 

(named for W. T. Coleman, 1824–93, the owner of the mine where it was discovered), a mineral of the class of borates. In terms of chemical composition it is a hydrous calcium borate, Ca[B2BO4(OH)3].H2O. Complex chains composed of B(O, OH)4 tetrahedrons and BO3 triangles bonded into a three-dimensional structure through Ca2+ ions and H2O buffer molecules are present in the crystal structure. Colemanite crystallizes in a monoclinic system, forming short, colorless crystals of columnar or dipyramidal appearance, as well as continuous fine-grained masses. Hardness on the mineralogical scale, 4–4.5; density, 2,440–2,450 kg/m3.

Colemanite is formed by precipitation, along with other borates (hydroboracite, inyoite, and borax), gypsum, and clayey deposits, from boron-containing brines of continental lakes. It is also found in the deposits of hot springs. Along with the other borates, colemanite is used as a boron ore.

References in periodicals archive ?
Sugozu (2009) produced the brake pad specimens using ulexite, colemanite, boric acid and borax pentahydrate which are boron derivatives, and then examined the properties of the produced brake pads including the friction, wear, and resistance.
Sevim, "Colemanite ore waste concrete with low shrinkage and high split tensile strength," Materials and Structures, vol.
Three other commercially available B sources viz., borax, ulexite and colemanite were also co-granulated with MAP.
Yartasi, A Semiempirical Kinetic Model for Dissolution of Colemanite in Aqueous CH3COOH Solutions, Industrial and Engineering Chemistry Research, 35(1996), No.7.
Olgun, "Removal of acid blue 62 on aqueous solution using calcinated colemanite ore waste," Journal of Hazardous Materials, vol.
Gok, "Mechanical properties of polymer concretes containing different amount of hematite or colemanite," Polimery, vol.
Boron production is carried out at four mines and four associated processing plants which produce three different borate minerals: colemanite, ulexite and tincal.
For the lover of minerals from below sea level, Tony had colemanite crystals from the Boraxo pit, Death Valley, Inyo County, California in short-prismatic, spear-shaped crystals in radiating and upstanding groups.
Although it's fairly dark inside my head, I can see by the light of my colemanite lamp that much of the basic structure of the skull appears to be New England granite.
Within commercial products and the most important minerals that contain boron are the borax pentahydrate, sodium perborate, boric acid, colemanite and ulexite.