Tantalite

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Tantalite
Tantalite.jpg
Tantalite, Pilbara district, Australia
General
Category Oxide minerals
Formula
(repeating unit)
(Fe,Mn)Ta2O6
Strunz classification 04.DB.35
Identification
Color Dark black, iron-black to dark brown, reddish brown
Crystal system Orthorhombic
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]
Manganotantalite from Alto do Giz, RN, Brazil

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[edit]

Tantalite has been found in Australia, Brazil, Canada, Colombia (Guainía and Vichada), Egypt, northern Europe, Madagascar, Namibia, Nigeria, Rwanda, the United States (California, Colorado, Maine, and Virginia), and Zimbabwe. Brazil has the world's largest reserve of tantalite (52.1%).[4] In 2006, 75% of world tantalite production came from Australia.[4]

Sustainability[edit]

The mining of tantalite causes many ecological and social problems in Democratic Republic of Congo.[5][6]

References[edit]

  1. ^ "TANTALITE (Iron Manganese Tantalum Niobium Oxide)". Galleries.com. Retrieved 2011-10-25. 
  2. ^ a b Tantalite. Mindat.org (2011-09-07). Retrieved on 2011-10-30.
  3. ^ P. Cerny et al. (1992). "The tantalite-tapiolite gap: natural assemblages versus experimental data". Canadian Mineralogist 30: 587. 
  4. ^ a b Papp, John F. (2006). "2006 Minerals Yearbook Nb & Ta". US Geological Survey. Retrieved 2008-06-03. 
  5. ^ Coltan, Gorillas and cellphones. Cellular-news.com (2001-04-03). Retrieved on 2011-10-30.
  6. ^ The Coltan Scandal. Geology.about.com (2010-07-04). Retrieved on 2011-10-30.

External links[edit]