Mineral - Phosgenite
Phosgenite
Chemical Properties
Mineral Class
Carbonates
Toxicity
middle
Formula
Pb₂[Cl₂|CO₃]
Unit Cell
a=8.16 c=8.88 Z=4
Physical Properties
Hardness
2 - 3
Streak
white
Density
Very Heavy (>6)
Cleavage
Distinct after {001} and {110}, undistinct after {010}
Fracture
conchoidal
Tenacity
Elastic-flexible
Optical Properties
Color
brownyellowcolorless
Birefringence
0.027
Luster
Adamantine
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
tetragonal
Point Group
ditetragonal-dipyramidal - 4/m 2/m 2/m
Space Group
P4/mbm (127)
Habit
blocky, prismatic, tabular
Formation
Secondary, through the chemical weathering of lead-bearing primary ores (mostly galena) in the oxidation zone under the influence of chloride-bearing, carbonate-rich solutions
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Phosgenite
Composition
Elements
Mass
CO₂
8.13
PbO
81.78
Cl
12.91
O=Cl₂
2.91
Russia (Palache et al. 1952)