Yeatmanite

Formula: Mn₉Zn₆Sb₂Si₄O₂₈

Origin of name: for Pope Yeatman (1861-1953), American mining engineer at the discovery locality.

Crystal system: Triclinic

Crystal class: 1

Twinning:

Unit cell: a = 5.604, b = 11.602, c = 9.058, α = 92.167°, β = 100.9°, γ = 77.3°

Colour: Clove-brown

Diaphaneity: 

Luster: Vitreous

Habit: crystals pseudo-orthorhombic, platy, twinned, anhedral grains

Hardness: 4

Specific gravity: 4.91 to 5.02

Cleavage: 1; {100} perfect

Tenacity: Brittle

Streak: Light brown

Synonyms/varieties:

Comments: