Hedenbergite - CaFeSi₂O₆

Habit: Black, dark green or green brown. Short prismatic crystals in columnar or acicular aggregates; also granular, lamellar or massive. Vitreous or dull luster; transparent to opaque. Whitish green streak.

Environment: Occurs in metamorphosed iron formations, ironmanganese skarns, alkalic granites and xenoliths in kimberlite.

Etymology: Named in honor of the Swedish chemist M.A. Ludwig Hedenberg, who first described the mineral.