Mineral - Wallisite
Wallisite
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
middle
Formula
PbTl(Cu,Ag)As₂S₅
Unit Cell
a=9,22 b=8,52 c=7,98 α=55° β=62° γ=69° Z=2
Physical Properties
Hardness
3 - 3.5
Streak
brown
Density
Cleavage
Gut nach {001}
Fracture
nd
Tenacity
Brittle
Optical Properties
Color
blackgray
Birefringence
/
Luster
Metallic
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
triclinic
Point Group
Space Group
Habit
coarse, granular, massive, prismatic
Formation
hydrothermale Bildung in Dolomit
Paragenesis
Twinning
Rarity
Very rare
Synonyms
Wallisite
Composition
Elements
Mass
Pb
25,2
Tl
26,0
Cu
6,9
Ag
2,7
As
20,5
S
19,0
Schweiz
Groups and Members
Wallisit-Gruppe