Tapiolite

Tapiolite
General
Category Mineral
Formula
(repeating unit)
(Fe, Mn)(Nb, Ta)2O6
Crystal system Tetragonal
Crystal class Ditetragonal dipyramidal (4/mmm)
H-M symbol: (4/m 2/m 2/m)
Space group P42/mnm
Identification
References [1]

Tapiolite [(Fe, Mn)(Nb, Ta)2O6] is a black mineral series that is an ore of niobium and tantalum. The tapiolite group includes tapiolite-(Fe) or ferrotapiolite and tapiolite-(Mn) or manganotapiolite.[2][3][4] Tapiolite-(Fe) is by far the more common of the two.[5][6]

The minerals have a submetallic luster and a high specific gravity with tapiolite-Fe having a higher specific gravity (7.90)[5] versus 7.72 for tapiolite-Mn.[6]

The mineral was named in 1863 after the forest god Tapio of Finnish mythology, and the original tapiolite material came from Sukula, Tammela, Tavastia Proper, Finland.[2][7]

Tapiolite is very close to columbite and tantalite. Those minerals have the same chemical composition, but different crystal symmetry orthorhombic for tantalite or columbite and tetragonal for tapiolite.[8]

Crystal structure of tapiolite. 

References


This article is issued from Wikipedia - version of the 11/30/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.