Tancaite-(Ce)

tancaite-(Ce)

Images

Formula: FeCe(MoO₄)₃.3H₂O
Hydrated molybdate, cerium-bearing mineral
Crystal system: Trigonal
Specific gravity: 3.834 calculated
Hardness: 4 to 4½
Streak: Yellow
Colour: Red or pale brown
Luminescence: Not fluorescent under UV
Environments

Plutonic igneous environments
Hydrothermal environments

Localities

At the type locality, Punta de Su Seinargiu, Sarroch, Metropolitan City of Cagliari, Sardinia, Italy, tancaite-(Ce) occurs within cavities in the quartz veins which cut the granite. It is a secondary mineral formed in the oxidation zone of a sulphide ore vein. Associated minerals are quartz, muscovite, molybdenite, pyrite and a mendozavilite-like phase. Tancaite-(Ce) is red or pale brown in colour, with a vitreous to adamantine lustre (EJM 32.347–354).
It occurs as small truncated octahedra up to 0.2 mm in size (Mindat).
Tancaite-(Ce) from Punta de Su Seinargiu - Image

Back to Minerals