Greenish plates of the very rare mineral zincochromite from the type locality (Srednyaya Padma, Karelia, Northern Region, Russian Federation) and one of the very few known localities worldwide, embedded in an acrylic bearer. — Photo: David Hospital · CC BY-SA 4.0
Zincochromite
The zinc analogue of chromite — described in 1987 from a uranium deposit at Lake Onega.
Intro adapted from Wikipedia (CC BY-SA).
Zincochromite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula ZnCr₂O₄.
It crystallizes in the cubic crystal system (space group Fd3m). It is a member of the Spinel structural group.
Key properties: Mohs hardness 5.8; specific gravity 5.434; Brown streak; Semimetallic luster; optically isotropic.
IMA symbol Zchr, IMA status: approved, named in 1986.
Replacing chromian aegirine in micaceous metasomatites.
It is found associated with Quartz, chromian aegirine, and its amorphous breakdown products.
The name refers to ZINC and CHROMium in the composition.