| 词条 | Tantalite |
| 释义 |
| name = Tantalite | boxwidth = | boxbgcolor = | image = Tantalite.jpg | imagesize = 260px | alt = | caption = Tantalite, Pilbara district, Australia | category = Oxide minerals | formula = (Fe,Mn)Ta2O6 | molweight = | strunz = 4.DB.35 | dana = | system = Orthorhombic | class = Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) | unit cell = | color = Dark black, iron-black to dark brown, reddish brown | colour = | habit = | twinning = | cleavage = Good in one direction | fracture = Subconchoidal | tenacity = | mohs = 6-6.5 | luster = Submetallic to almost resinous | streak = Brownish-red to black | diaphaneity = | gravity = 8.0+ | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = [1][2] }} The mineral group tantalite [(Fe, Mn)Ta2O6] is the primary source of the chemical element tantalum. It is chemically similar to columbite, and the two are often grouped together as a semi-singular mineral called coltan or "columbite-tantalite" in many mineral guides. However, tantalite has a much greater specific gravity than columbite (8.0+ compared to columbite's 5.2).[2] Iron-rich tantalite is the mineral tantalite-(Fe) or ferrotantalite and manganese-rich is tantalite-(Mn) or manganotantalite. Tantalite is also very close to tapiolite. Those minerals have same chemical composition, but different crystal symmetry orthorhombic for tantalite and tetragonal for tapiolite.[3] Tantalite is black to brown in both color and streak. Manganese-rich tantalites can be brown and translucent. OccurrenceTantalite occurs in granitic pegmatites that are rich in rare-earth elements, and in placer deposits derived from such rocks.[4] It has been found in Australia, Brazil, Canada, Colombia (Guainía and Vichada), Egypt, northern Europe, Madagascar, Namibia, Nigeria, Rwanda, The Democratic Republic of Congo, the United States (California, Colorado, Maine, and Virginia), and Zimbabwe. Brazil has the world's largest reserve of tantalite (52.1%).[5] In 2006, 75% of world tantalite production came from Australia.[5] SustainabilityThe mining of tantalite causes many environmental and social problems in Democratic Republic of Congo.[6][7] See also
References1. ^{{cite web|title=TANTALITE (Iron Manganese Tantalum Niobium Oxide)|url=http://www.galleries.com/Tantalite|publisher=Galleries.com|accessdate=2011-10-25}} 2. ^1 Tantalite. Mindat.org (2011-09-07). Retrieved on 2011-10-30. 3. ^{{cite journal|author=P. Cerny|title=The tantalite-tapiolite gap: natural assemblages versus experimental data|journal= Canadian Mineralogist |volume=30 |year=1992|pages= 587|url=http://rruff.geo.arizona.edu/doclib/cm/vol30/CM30_587.pdf |display-authors=etal}} 4. ^{{cite journal|last1=Melcher|first1=Frank|last2=et. al.|title=Fingerprinting of conflict minerals: columbite-tantalite ("coltan") ores|journal=SGA News|date=June 2008|issue=23|page=1|url=https://www.researchgate.net/profile/Thomas_Oberthuer/publication/228401189_Fingerprinting_of_conflict_minerals_Columbite-tantalite_coltan_ores_SGA_News_No_23/links/02bfe512b550d9804a000000.pdf|accessdate=10 August 2016}} 5. ^1 {{cite web |publisher = US Geological Survey |last = Papp |first = John F. |title = 2006 Minerals Yearbook Nb & Ta |date = 2006|url = http://minerals.usgs.gov/minerals/pubs/commodity/niobium/#pubs |accessdate = 2008-06-03}} 6. ^Coltan, Gorillas and cellphones {{Webarchive|url=https://web.archive.org/web/20050407083927/http://www.cellular-news.com/coltan/ |date=2005-04-07 }}. Cellular-news.com (2001-04-03). Retrieved on 2011-10-30. 7. ^The Coltan Scandal. Geology.about.com (2010-07-04). Retrieved on 2011-10-30. External links{{Commons category}}
5 : Tantalum minerals|Niobium minerals|Manganese minerals|Oxide minerals|Orthorhombic minerals |
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