Many small black aggregates of the very rare Sn-Ta oxide mineral ferrowodginite from a locality in Uganda (Nyanga #2 Pegmatite, Ankole, Mbarara District, Western Region, Uganda). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Ferrowodginite
Ferrowodginite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Fe²⁺Sn⁴⁺Ta₂O₈.
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 7.02; Dark brown streak; Vitreous luster.
IMA symbol Fwdg, IMA status: approved, named in 1984.
Found in museum specimens from a granite pegmatite.
It is found associated with Tantalian cassiterite, tapiolite, bismuth, stannomicrolite.
The name refers to its content of FERROus iron and its relation to wodginite.