Ardaite

Formula:  (Pb,Fe)₁₀Sb₆S₁₇Cl₄

Origin of name:  From locality, Arda River, Bulgaria

Crystal system:  Monoclinic

Crystal class:  Unknown

Twinning:

Unit cell: a = 21.09 Å, b = 22.11 Å, c = 8.05 Å, b = 103.02°

Colour:  In reflected light greenish grey or bluish green

Diaphaneity: Opaque

Luster:  Metallic

Habit:  Microscopic aggregates of acicular crystals

Hardness: 2.5-3

Specific gravity:  6.17

Cleavage:  None

Tenacity:

Streak:

Synonyms/varieties: 

Comments:  Found in polished section only. Occurrence in polymetallic ore deposits