Achalaite
A black, metallic-looking member of the wodginite group discovered in 2013, built from iron, titanium, niobium and tantalum oxides.
Intro adapted from Wikipedia (CC BY-SA).
Achalaite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Fe²⁺TiNb₂O₈.
It crystallizes in the monoclinic crystal system (space group C2/c). It is a member of the Wodginite structural group.
Key properties: Mohs hardness 5.5; specific gravity 6.285; Black streak; Metallic luster.
IMA symbol Ahl, IMA status: approved, named in 2013.
Found in the intermediate zone of a topaz- and columbite-tantalite-bearing granitic pegmatite which is concordant with the schistosity of regional metasedimentary rocks.
It is found associated with Ta-rich rutile, pyrochlore supergroup minerals, cassiterite, columbite-(Mn), ixiolite, traces of bismuth, topaz, triplite, microlite group minerals.
The name is taken from the type locality, the Achala granite batholith, Argentina.