Tantalite

Big Photo

Manganotantalite
Brazil
6.41 carats
© Rarestone.com

Tantalite is the name given to a group of related minerals containing tantalum, oxygen and a metal such as Iron or Manganese.

The closely-related minerals columbite and tapiolite are often confused for tantalite.

See also the related gemstone stibiotantalite.


Tantalite Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 

Tantalite Gemstones by Size

This table shows distribution of Tantalite gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:0.74 cts
Heaviest:8.35 cts
Average:4.77 cts
Total photos:5
Do you have a larger Tantalite? Why not upload a photo?
0.74ct to 1.50ct1.50ct to 2.26ct2.26ct to 3.02ct3.02ct to 3.78ct3.78ct to 4.55ct4.55ct to 5.31ct5.31ct to 6.07ct6.07ct to 6.83ct6.83ct to 7.59ct7.59ct to 8.35ct
General Information
Varieties/Types:
Manganotantalite - A manganese-rich variety of Tantalite.
Chemical Formula
(Fe,Mn)Ta
 
2
O
 
6
Walter Schumann, Gemstones of the world (2001)
More from other references
Photos of natural/un-cut material from mindat.org
Physical Properties of Tantalite
Mohs Hardness6 to 6.5
Walter Schumann, Gemstones of the world (2001)
More from other references
Specific Gravity5.18 to 8.20
Walter Schumann, Gemstones of the world (2001)
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Cleavage QualityDistinct
Arthur Thomas, Gemstones (2009)
FractureSub-Conchoidal
Arthur Thomas, Gemstones (2009)
Optical Properties of Tantalite
Refractive Index2.190 to 2.457
Arthur Thomas, Gemstones (2009)
Optical CharacterBiaxial/+
Arthur Thomas, Gemstones (2009)
Birefringence0.083
Arthur Thomas, Gemstones (2009)
PleochroismSometimes strong
Arthur Thomas, Gemstones (2009)
DispersionNil
Arthur Thomas, Gemstones (2009)
Colour
Colour (General)Red-brown, brown, black
Walter Schumann, Gemstones of the world (2001)
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TransparencyTransparent
Walter Schumann, Gemstones of the world (2001)
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LustreSubmetallic
Arthur Thomas, Gemstones (2009)
Crystallography of Tantalite
Crystal SystemOrthorhombic
Walter Schumann, Gemstones of the world (2001)
More from other references
HabitPrismatic
Arthur Thomas, Gemstones (2009)
Geological Environment
Where found:Commonly occurs in lithium-rich granitic pegmatites.
Arthur Thomas, Gemstones (2009)
Further Information
Mineral information:Tantalite information at mindat.org
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