Cassiterite is a tinoxide mineral, SnO2. It is generally opaque, but it is translucent in thin crystals. Its luster and multiple crystal faces produce a desirable gem. Cassiterite was the chief tin ore throughout ancient history and remains the most important source of tin today.
Cassiterite
Cassiterite with muscovite, from Xuebaoding, Huya, Pingwu, Mianyang, Sichuan, China (size: 100 x 95 mm, 1128 g)
Close up of cassiterite crystals, Blue Tier tinfield, Tasmania, Australia
Most sources of cassiterite today are found in alluvial or placer deposits containing the weathering-resistant grains. The best sources of primary cassiterite are found in the tin mines of Bolivia, where it is found in crystallised hydrothermal veins. Rwanda has a nascent cassiterite mining industry. Fighting over cassiterite deposits (particularly in Walikale) is a major cause of the conflict waged in eastern parts of the Democratic Republic of the Congo.[7][8] This has led to cassiterite being considered a conflict mineral.
Crystal twinning is common in cassiterite and most aggregate specimens show crystal twins. The typical twin is bent at a near-60-degree angle, forming an "elbow twin". Botryoidal or reniform cassiterite is called wood tin.
Cassiterite is also used as a gemstone and collector specimens when quality crystals are found.
Stalactitic-botryoidal, banded, "wood tin" cassiterite, 5.0 x 4.9 x 3.3 cm, Durango, Mexico
Etymology
The name derives from the Greekkassiteros for "tin": this comes from the Phoenician word Cassiterid referring to the islands of Ireland and Great Britain,[citation needed] the ancient sources of tin; or, as Roman Ghirshman (1954) suggests, from the region of the Kassites, an ancient people in west and central Iran.
^Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Cassiterite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 19 June 2022.
^Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20th ed.). New York: John Wiley and Sons. pp. 306–307. ISBN0-471-80580-7.
^Watt, Louise (2008-11-01). "Mining for minerals fuels Congo conflict". Yahoo! News. Yahoo! Inc. Associated Press. Retrieved 2009-09-03.
^Polgreen, Lydia (2008-11-16). "Congo's Riches, Looted by Renegade Troops". The New York Times. Retrieved 2008-11-16.
External links
Wikimedia Commons has media related to Cassiterite.
January 13, 2023
cassiterite, oxide, mineral, sno2, generally, opaque, translucent, thin, crystals, luster, multiple, crystal, faces, produce, desirable, chief, throughout, ancient, history, remains, most, important, source, today, with, muscovite, from, xuebaoding, huya, ping. Cassiterite is a tin oxide mineral SnO2 It is generally opaque but it is translucent in thin crystals Its luster and multiple crystal faces produce a desirable gem Cassiterite was the chief tin ore throughout ancient history and remains the most important source of tin today CassiteriteCassiterite with muscovite from Xuebaoding Huya Pingwu Mianyang Sichuan China size 100 x 95 mm 1128 g GeneralCategoryOxide mineralsFormula repeating unit SnO2IMA symbolCst 1 Strunz classification4 DB 05Crystal systemTetragonalCrystal classDitetragonal dipyramidal 4 mmm H M symbol 4 m 2 m 2 m Space groupP42 mnmUnit cella 4 7382 4 A c 3 1871 1 A Z 2IdentificationColorBlack brownish black reddish brown brown red yellow gray white rarely colorlessCrystal habitPyramidic prismatic radially fibrous botryoidal crusts and concretionary masses coarse to fine granular massiveTwinningVery common on 011 as contact and penetration twins geniculated lamellarCleavage 100 imperfect 110 indistinct partings on 111 or 011 FractureSubconchoidal to unevenTenacityBrittleMohs scale hardness6 7LusterAdamantine to adamantine metallic splendent may be greasy on fracturesStreakWhite to brownishDiaphaneityTransparent when light colored dark material nearly opaque commonly zonedSpecific gravity6 98 7 1Optical propertiesUniaxial Refractive indexnw 1 990 2 010 ne 2 093 2 100Birefringenced 0 103PleochroismPleochroic haloes have been observed Dichroic in yellow green red brown usually weak or absent but strong at timesFusibilityinfusibleSolubilityinsolubleReferences 2 3 4 5 6 Contents 1 Occurrence 2 Crystallography 3 Etymology 4 References 5 External linksOccurrence Edit Cassiterite bipyramids edge length ca 30 mm Sichuan China Close up of cassiterite crystals Blue Tier tinfield Tasmania Australia Most sources of cassiterite today are found in alluvial or placer deposits containing the weathering resistant grains The best sources of primary cassiterite are found in the tin mines of Bolivia where it is found in crystallised hydrothermal veins Rwanda has a nascent cassiterite mining industry Fighting over cassiterite deposits particularly in Walikale is a major cause of the conflict waged in eastern parts of the Democratic Republic of the Congo 7 8 This has led to cassiterite being considered a conflict mineral Cassiterite is a widespread minor constituent of igneous rocks The Bolivian veins and the 4500 year old workings of Cornwall and Devon England are concentrated in high temperature quartz veins and pegmatites associated with granitic intrusives The veins commonly contain tourmaline topaz fluorite apatite wolframite molybdenite and arsenopyrite The mineral occurs extensively in Cornwall as surface deposits on Bodmin Moor for example where there are extensive traces of a hydraulic mining method known as streaming The current major tin production comes from placer or alluvial deposits in Malaysia Thailand Indonesia the Maakhir region of Somalia and Russia Hydraulic mining methods are used to concentrate mined ore a process which relies on the high specific gravity of the SnO2 ore of about 7 0 Crystallography Edit Crystal structure of cassiterite Crystal twinning is common in cassiterite and most aggregate specimens show crystal twins The typical twin is bent at a near 60 degree angle forming an elbow twin Botryoidal or reniform cassiterite is called wood tin Cassiterite is also used as a gemstone and collector specimens when quality crystals are found Stalactitic botryoidal banded wood tin cassiterite 5 0 x 4 9 x 3 3 cm Durango MexicoEtymology EditThe name derives from the Greek kassiteros for tin this comes from the Phoenician word Cassiterid referring to the islands of Ireland and Great Britain citation needed the ancient sources of tin or as Roman Ghirshman 1954 suggests from the region of the Kassites an ancient people in west and central Iran References Edit Warr L N 2021 IMA CNMNC approved mineral symbols Mineralogical Magazine 85 3 291 320 Bibcode 2021MinM 85 291W doi 10 1180 mgm 2021 43 S2CID 235729616 Mineralienatlas Anthony John W Bideaux Richard A Bladh Kenneth W Nichols Monte C 2005 Cassiterite PDF Handbook of Mineralogy Mineral Data Publishing Retrieved 19 June 2022 Cassiterite Mindat org Webmineral Hurlbut Cornelius S Klein Cornelis 1985 Manual of Mineralogy 20th ed New York John Wiley and Sons pp 306 307 ISBN 0 471 80580 7 Watt Louise 2008 11 01 Mining for minerals fuels Congo conflict Yahoo News Yahoo Inc Associated Press Retrieved 2009 09 03 Polgreen Lydia 2008 11 16 Congo s Riches Looted by Renegade Troops The New York Times Retrieved 2008 11 16 External links Edit Wikimedia Commons has media related to Cassiterite Retrieved from https en wikipedia org w index php title Cassiterite amp oldid 1125953812, wikipedia, wiki, book, books, library,
