Black crystal group of the very rare Fe vanadate mineral schubnelite from the TL in Gabon (Mounana Mine, Franceville, Haut-Ogooue, Gabon) and only one of 4 known localities worldwide. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Schubnelite
Schubnelite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Fe³⁺(V⁵⁺O₄)·H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Schubnelite structural group.
Key properties: specific gravity 3.28–3.29; Brilliant luster; optically biaxial.
IMA symbol Shb, IMA status: approved, named in 1970.
At the base of the oxidized zone of a uranium deposit (Mounana mine, Gabon); in a hydrothermal gold deposit (Gold Quarry mine, Nevada, USA).
It is found associated with Fervanite, goethite (Mounana mine, Gabon); kazakhstanite, fervanite, tyuyamunite (Gold Quarry mine, Nevada, USA).
The mineral was named to honor Henri-Jean Schubnel (1935–), mineralogist and gemologist, Bureau de Recherches Géologiques et Minières, Paris, France.