Bustamite

bustamite

glaucochroite

wollastonite

johannsenite

Images

Formula: CaMn²⁺Si₂O₆
Inosilicate (chain silicate), single width, wollastonite group, manganese-bearing mineral
Crystal System: Triclinic
Specific gravity: 3.32 to 3.43 measured, 3.421 calculated
Hardness: 5½ to 6½
Streak: White
Colour: Pale to medium pink; brownish red; colourless to yellowish pink in transmitted light. Pink colour fades on exposure to sunlight
Solubility: Partly soluble in hydrochloric acid
Environments:

Metamorphic environments

Bustamite occurs in manganese ores formed by metamorphism of manganese-bearing sediments. The type locality is a carbonate-silicate hosted zinc deposit. Common associates include calcite, diopside, glaucochroite, grossular, johannsenite, rhodonite and wollastonite.

Alteration

bustamite, tephroite and calcite to glaucochroite and CO₂
CaMn²⁺Si₂O₆ + Mn²⁺₂(SiO₄) + 2CaCO₃ ⇌ 3CaMn²⁺(SiO₄) + 2CO₂
(DHZ 1A p348)

Back to Minerals