Composition: PbFe2+Ge6+(Ge4+2O7)(OH)2.H2O
Crystal System : Monoclinic
Colours: Colourless, pale-green
Lustre : Sub-adamantine
Hardness (H) : 4
Specific Gravity (S.G) : 4.97
Year of Discovery: 1979
IMA Number: 1979-029
IMA Status: Approved
Discovered By: Wolfgang Bartelke (German collector)
Named for: Discoverer
References: Keller et al. (1981a)

 Tsumeb is the Type Locality


Extremely rare.


  • Supergene
  • 2nd Oxidation Zone

Paragenetic and General Notes

An inconspicuous, yet distinctive, mineral occurring typically in shallow vugs in oxidising germanium-rich sulphide ores. Colourless to pale green crystals, <1mm, tabular to acicular, but with highly charcteristic notches.