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Baryte, or barite, (BaSO4) is a mineral consisting of barium sulfate.[1] The baryte group consists of baryte, celestine, anglesite and anhydrite. Baryte itself is generally white or colorless, and is the main source of barium. Baryte and celestine form a solid solution (Ba,Sr)SO4.[2]
[edit] Names and history The radiating form, sometimes referred to as Bologna Stone, attained some notoriety among alchemists for the phosphorescent specimens found in the 1600s near Bologna by Vincenzo Cascariolo[3]. The name baryte is derived from the Greek word βαρύς (heavy). The American spelling barite[1] is used by USGS [4] and more often used in modern Scientific journals including those published by the Netherlands-based Elsevier journals. The International Mineralogical Association adopted "barite" as the official spelling when it formed in 1959[citation needed], but recommended adopting the older "baryte" spelling in 1978[5], notably ignored by the Mineralogical Society of America. The American Petroleum Institute specification API 13/ISO 13500 which governs baryte for drilling purposes does not refer to any specific mineral, but rather a material that meets that specification, in practice this is usually the mineral baryte. The term "primary baryte" refers to the first marketable product, which includes crude baryte (run of mine) and the products of simple beneficiation methods, such as washing, jigging, heavy media separation, tabling, flotation, and magnetic separation. Most crude baryte requires some upgrading to minimum purity or density. Baryte that is used as an aggregate in a "heavy" cement is crushed and screened to a uniform size. Most baryte is ground to a small, uniform size before it is used as a filler or extender, an addition to industrial products, or a weighting agent in petroleum well drilling mud. [edit] Other names Baryte has gone by other names such as barytine[5], barytite[5], schwerspath[5], barytes[1], Heavy Spar[1], or tiff.[6] | | Baryte (Barite) |  | | General | | Category | Sulfate mineral, Barite Group | | Chemical formula | BaSO4 | | Strunz classification | 07.AD.35 | | Dana classification | 28.03.01.01 | | Identification | | Color | Colorless, white, light shades of blue, yellow, grey, brown | | Crystal habit | Tabular parallel to base, fibrous, nodular to massive | | Crystal system | Orthorhombic Dipyramidal (2/m 2/m 2/m) | | Cleavage | Perfect cleavage parallel to base and prism faces: {001} Perfect, {210} Perfect, {010} Imperfect | | Fracture | Irregular/uneven | | Tenacity | Brittle | | Mohs scale hardness | 3-3.5 | | Luster | Vitreous, pearly | | Streak | White | | Diaphaneity | transparent to opaque | | Specific gravity | 4.3-5 | | Density | 4.48 g/cm3[2] | | Optical properties | biaxial positive | | Refractive index | nα = 1.634 - 1.637 nβ = 1.636 - 1.638 nγ = 1.646 - 1.648 | | Birefringence | 0.012 | | Fusibility | 4, yellowish green barium flame | | Diagnostic features | white color, high specific gravity, characteristic cleavage and crystals | | Solubility | low | | References | [1][6][7][8] | | [edit] Mineral associations and locations Baryte occurs in a large number of depositional environments, and is deposited through a large number of processes including biogenic, hydrothermal, and evaporation, among others.[2] Baryte commonly occurs in lead-zinc veins in limestones, in hot spring deposits, and with hematite ore. It is often associated with the minerals anglesite and celestine. It has also been identified in meteorites.[9] Baryte has been found in locations in Cheshire, Connecticut, De Kalb, New York, Fort Wallace, New Mexico as well as quarried in Arkansas, Connecticut, Virginia, North Carolina, Georgia, Tennessee, Kentucky, Nevada, and Missouri in the USA[1]. Outside of the USA, localities include Baia Sprie, Romania, Westmoreland, Cornwell, Cumberland, Derbyshire, and Surrey in the UK[1], China, India, Morocco, Peru, Chile, Liberia, Turkey, Ireland, Canada, Brazil, Greece, and Barberton Mountain Land, South Africa[10] Some 77% worldwide is used as a weighting agent for drilling fluids in oil and gas exploration. Other uses are in added-value applications which include the car, electronics, TV screen, rubber, and glass ceramics and paint industry, radiation shielding and medical applications (for example, a barium meal before a contrast CAT scan). Baryte is supplied in a variety of forms and the price depends on the amount of processing; filler applications commanding higher prices following intense physical processing by grinding and micronising, and there are further premiums for whiteness and brightness and colour. Baryte is used in the manufacture of paints and paper.[4] Historically baryte was used for the production of barium hydroxide for sugar refining, and as a white pigment for textiles, paper, and paint[1]. Although baryte contains a "heavy" metal (barium), it is not considered to be a toxic chemical by most governments because of its extreme insolubility. |  Baryte with Galena and Hematite from Poland  Large barite crystals from Nevada, USA | [edit] References - ^ a b c d e f g h Dana, James Dwight; Ford, William Ebenezer (1915). Dana's Manual of Mineralogy for the Student of Elementary Mineralogy, the Mining Engineer, the Geologist, the Prospector, the Collector, Etc. (13 ed.). John Wiley & Sons, Inc.. pp. 299-300. http://www.archive.org/details/danasmanualmine00fordgoog.
- ^ a b c Hanor, J. (2000). "Barite-celestine geochemistry and environments of formation". Reviews in Mineralogy 40: 193-275. ISBN 0-939950-52-9.
- ^ History of the Bologna stone
- ^ a b USGS page for Barite
- ^ a b c d "International Mineralogical Association: Commission on New Minerals and Mineral Names". Mineralogical Magazine 38: 102-105. March 1971. doi:10.1180/minmag.1971.038.293.14.
- ^ a b http://www.mindat.org/min-549.html Mindat
- ^ http://webmineral.com/data/Barite.shtml Webmineral data
- ^ http://rruff.geo.arizona.edu/doclib/hom/baryte.pdf Handbook of Mineralogy
- ^ Rubin, Alan E. (March 1997). "Mineralogy of meteorite groups". Meteoritics & Planetary Science 32: 231-247. http://adsabs.harvard.edu/abs/1997M%26PS...32..231R.
- ^ Duchač, K. C; Hanor, J. S. (September 1987). "Origin and timing of the metasomatic silicification of an early Archaean komatiite sequence, Barberton Mountain Land, South Africa". Precambrian Research 37 (2): 125-146. doi:10.1016/0301-9268(87)90075-1. ISSN 0301-9268.
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