Hübnerite

Field of view: 10 mm. Hübnerite associated with rhodonite. The quadrangular black prism is hübnerite. The surrounding pink host is rhodonite, and the pale black parts are fine spessartine crystals.

Recovered from a chert-hosted bedded manganese deposit subjected to Hornblende-hornfels facies contact metamorphism by S-type (Ilmenite-series) granodiorite. Formed in the Late Cretaceous (90 Ma).

Hübnerite from this location was described in 1958.