Wilhelmkleinite

Wilhelmkleinite


Composition:

ZnFe3+2(AsO4)2(OH)2

Crystal System : Monoclinic
Colours: Blackish-green
Lustre : Adamantine (fractures); Dull (faces)
Hardness (H) : 4.5
Specific Gravity (S.G) : 4.36
IMA Number: 1997-034
IMA Status: Approved
Discovered By: Georg Gebhard (German collector) / Charles Key (American dealer)
Named for: Wilhelm Klein (Tsumeb mine captain)

Tsumeb is the Type Locality

Distribution

Extremely rare. The type specimen is from the third oxidation zone, but probably also found in the second oxidation zone (?).

Occurrence

  • Supergene
  • 2nd Oxidation Zone
  • 3rd Oxidation Zone

Paragenetic and General Notes

On the type specimen wilhelmkleinite occurs as blackish-green spear-head shaped crystals, to 5 mm, with prominent interpenetration twinning on (101); associated minerals are adamite, gertremmelite and scorodite.

A specimen in the W. (Bill) Pinch collection exhibits a completely different paragenesis in which wilhelmkleinite is associated with parasymplesite (www.williampinch.com). This specimen was originally in the collection of Tsumeb mineralogist John Innes and was labelled as an "unknown" (Bill Pinch, personal communication to M.Southwood, February 2016). It's vintage (Innes was at Tsumeb in the late 1970s and early 1980s) implies that it was almost certainly recovered from the second oxidation zone.