Lead chloro-vanadate. The vanadate radical (VO4) may be partially replaced by an arsenate radical (AsO4), thus forming a series with Mimetite.
Variable Formula
Pb5([V,As]O4)3Cl
Color
Bright red, orange, brown, yellow-brown, yellow, greenish-brown, gray. Crystals may also be multicolored.
Streak
Light yellow
Hardness
2.5 - 3
Crystal System
Hexagonal
Crystal Forms and Aggregates
Occurs as prismatic and stubby hexagonal crystals, which are commonly partially hollow or may have a hopper growth pattern. Crystals are occasionally pyramidal. Also occurs as small hexagonal plates, as pyramidal clusters, as groups of bent or rounded crystals, fibrous, crusty, radiating, acicular, reniform, and mammilary.
Transparency
Transparent to opaque
Specific Gravity
6.7 - 7.2
Luster
Greasy to adamantine
Cleavage
None
Fracture
Conchoidal to uneven
Tenacity
Brittle
In Group
Phosphates; Vanadates
Striking Features
Color and luster, crystal habits, and occurrences
Environment
As a secondary mineral in the oxidation zone of lead ore deposits.