Tantalite
| Tantalite | |
|---|---|
 Tantalite, Pilbara district, Australia | |
| Allgemein | |
| Kategorie | Oxide minerals |
| Formula (repeating unit) | (Fe,Mn)Ta2O6 |
| Strunz classification | 04.DB.35 |
| Crystal system | Orthorhombic |
| Identification | |
| Color | Dark black, iron-black to dark brown, reddish brown |
| Cleavage | Good in one direction |
| Fracture | Subconchoidal |
| Mohs scale hardness | 6-6.5 |
| Luster | Submetallic to almost resinous |
| Streak | Brownish-red to black |
| Specific gravity | 8.0+ |
| 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.
Occurrence
Tantalite has been found in Egypt, Namibia, Nigeria, Canada, Madagascar,Rwanda, [[northern Europe, and Maine, California, Colorado and Virginia in the United States. Brazil has the world's largest reserve of tantalite (52.1%).[4] As at 2006, 75% of world tantalite production comes from Australia.[4]
Tantalite is also mined in Guainía and Vichada, Colombia.
Nachhaltigkeit
The mining of tantalite causes many ecological and social problems in Democratic Republic of Congo.[5][6]
References
- ^ "TANTALITE (Iron Manganese Tantalum Niobium Oxide)". Galleries.com. Retrieved 2011-10-25.
- ^ a b 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.
{{cite journal}}: Explicit use of et al. in:|author=(help) - ^ a b Papp, John F. (2006). "2006 Minerals Yearbook Nb & Ta". US Geological Survey. Retrieved 2008-06-03.
- ^ Coltan, Gorillas and cellphones. 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.
External links
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