Dark brown crystal aggregates of the rare Mn mineral tapiolite-(Mn) from a locality in Western Australia (Yinnietharra, Upper Gascoyne Shire, Western Australia, Australia). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Tapiolite-(Mn)
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. Tapiolite-(Fe) is by far the more common of the two. The minerals have a submetallic luster and a high specific gravity with tapiolite-Fe having a higher specific gravity (7.90) versus 7.72 for tapiolite-Mn. The mineral was named in 1863 after the forest god Tapio of Finnish mythology, and the original tapiolite material came from Sukula, Tammela, Kanta-Häme, Finland.
Intro adapted from Wikipedia (CC BY-SA).
Tapiolite-(Mn) is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Mn²⁺Ta₂O₆.
It crystallizes in the tetragonal crystal system (space group P4_2/mnm). It is a member of the Tapiolite structural group.
IMA symbol Tap-Mn, IMA status: approved, named in 1983.