Composition: Pb8(As3+2O5)2OCl6
Crystal System : Monoclinic
Colours: Brown
Lustre : Adamantine
Hardness (H) : 3
Specific Gravity (S.G) : 6.0
Year of Discovery: 1977
IMA Number: 1979-071
IMA Status: Approved
Discovered By: Georg Gebhard (German collector)
Named for: Discoverer

Tsumeb is the Type Locality


Extremely rare. The type specimen is from the second oxidation zone.


  • Supergene
  • 2nd Oxidation Zone

Paragenetic and General Notes

Apparently a once-only find. Gebhardite on the type specimen resembles millerite, with mimetite, reinerite, fraiponite, smithsonite, willemite, hematite, and quartz.