Barysilite

Formula:  Pb₈Mn(Si₂O₇)₃

Origin of name:  From silicon and Greek for heavy

Crystal system:  Hexagonal

Crystal class:  -3 2/m

Twinning:

Unit cell:

Colour:  White, pinkish white; tarnishes

Diaphaneity: Semitransparent

Luster:  Pearly on cleavage

Habit:  Massive or curved lamellar

Hardness:  3

Specific gravity:  6.550 to 6.706

Cleavage:  1; {0001} Distinct

Tenacity: Brittle, fracture uneven

Streak:

Synonyms/varieties:

Comments: Found in iron ores, as thin films and veinlets in a metamorphosed zinc orebody