General Information:
Chemical Formula:
PbFe++4As+++++10O22
Composition:
(Molecular Weight = 1,531.79 gm)
Iron 14.58 % Fe
Arsenic 48.91 % As
Lead 13.53 % Pb
Oxygen 22.98 % O
Empirical Formula:
PbFe2+4As10O22
Environment:
Oxidized ore bodies containing lead, iron, and As bearing sulfosalts.
Locality:
In a boulder of ore found at Tsumeb, Namibia.
Name Origin:
Named for mineral dealers Ludlow Smith and Locke Key, who discovered the mineral.
Physical Properties:
Cleavage:
[011] Perfect, [021] Perfect
Color:
reddish brown.
Density:
4.37 - 4.4, Average = 4.38
Habits:
Acicular - Occurs as needle-like crystals., ,
Hardness:
1.5-2 - Talc-Gypsum
Luster:
Subadamantine
Streak:
pale brown
More details...