Mineral - Beudantite
Beudantite
Chemical Properties
Mineral Class
Arsenates
Toxicity
middle
Formula
PbFe₃(AsO₄)(SO₄)(OH)₆
Unit Cell
a=7.34 c=17.04 Z=3
Physical Properties
Hardness
3.5 - 4.5
Streak
yellowgreen
Density
Heavy (3,5-6)
Cleavage
Distinct after {0001}
Fracture
Tenacity
Brittle
Optical Properties
Color
brownyellowgreen
Birefringence
0.014
Luster
Vitreous,
Resinous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
trigonal
Point Group
ditrigonal-scalenohedral - 3 m
Space Group
R 3 m (166)
Habit
Rhombohedral, tabular
Formation
Oxidation zone of lead deposits
Paragenesis
Twinning
Rarity
Rarely
Synonyms
Beudantite
Composition
Elements
Mass
SO₃
11.15
As₂O₅
16.02
Fe₂O₃
33.48
CuO
0.22
ZnO
0.11
PbO
31.22
H₂O
7.80
Montana (Palache et al. 1952)
Groups and Members
Alunite-Supergroup
Beudantite-Group