Tantalite, Pilbara district, Australia
|Crystal class||Dipyramidal (mmm) |
H-M symbol: (2/m 2/m 2/m)
|Color||Dark black, iron-black to dark brown, reddish brown|
|Cleavage||Good in one direction|
|Mohs scale hardness||6-6.5|
|Luster||Submetallic to almost resinous|
|Streak||Brownish-red to black|
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). Iron-rich tantalite is the mineral tantalite-(Fe) or ferrotantalite and manganese-rich is tantalite-(Mn) or manganotantalite.
Tantalite occurs in granitic pegmatites that are rich in rare-earth elements, and in placer deposits derived from such rocks. 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%).
- "TANTALITE (Iron Manganese Tantalum Niobium Oxide)". Galleries.com. Retrieved 2011-10-25.
- Tantalite. Mindat.org (2011-09-07). Retrieved on 2011-10-30.
- P. Cerny; et al. (1992). "The tantalite-tapiolite gap: natural assemblages versus experimental data" (PDF). Canadian Mineralogist. 30: 587.
- Melcher, Frank; et al. (June 2008). "Fingerprinting of conflict minerals: columbite-tantalite ("coltan") ores" (PDF). SGA News (23): 1. Retrieved 10 August 2016.
- Papp, John F. (2006). "2006 Minerals Yearbook Nb & Ta". US Geological Survey. Retrieved 2008-06-03.
- Coltan, Gorillas and cellphones Archived 2005-04-07 at the Wayback Machine. Cellular-news.com (2001-04-03). Retrieved on 2011-10-30.
- The Coltan Scandal. Geology.about.com (2010-07-04). Retrieved on 2011-10-30.
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