Germanite

Germanite


Composition: Cu26Fe4Ge4S32
Crystal System : Cubic
Colours: Pale greyish-pink, pinkish-brown, orange-brown
Lustre : Metallic
Hardness (H) : 4
Specific Gravity (S.G) : 4.46-4.59
Year of Discovery: 1920
IMA Number: 1922
IMA Status: Grandfathered
Discovered By: Wilhelm Klein (Tsumeb mine captain)
Named for: Composition (the element germanium)
References:

Pufahl (1922)

Tsumeb is the Type Locality

Distribution

Very common. Germanite was discovered in the upper levels of the mine (first oxidation zone).

Occurrence

  • Hypogene
  • 1st Oxidation Zone
  • 2nd Oxidation Zone
  • 3rd Oxidation Zone

Notable Finds

The first Ge mineral discovered at Tsumeb, as large, "pure" masses between depths of 140m and 180m. A second germanite zone occurred between 20 and 26 levels, with rare crystals of germanite to 5mm in cavities in the ore. A third zone was found deep in the third oxidation zone, (46 and 47 Levels) from which the largest recorded germanite crystal (a 30 mm tetrahedron) was recovered (Gebhard, 1999).

Paragenetic and General Notes

In massive sulphide ores comprising renierite; gallite; colusite; sphalerite; tennantite; galena; pyrite; chalcocite. Most, if not all, secondary Ge- and Ga- bearing minerals tend to occur on altered germanite-bearing ores. Germanite is a common mineral at Tsumeb, but occurs mostly as as microscopic inclusions in galena and tennantite; larger masses are comparatively uncommon (Keller, 1977).