Johillerite

Johillerite


Composition: Na(Mg,Zn)3Cu2+(AsO4)3
Crystal System : Monoclinic
Colours: Violet, violet-blue
Lustre : Vitreous
Hardness (H) : 3
Specific Gravity (S.G) : 4.15
IMA Number: 1980-014
IMA Status: Approved
Discovered By: Wolfgang Bartelke (German collector)
Named for: Johannes-Erich Hiller (German Mineralogist)
References: Keller et al. (1982)

Tsumeb is the Type Locality

Distribution

Extremely rare. The type specimen is from the second oxidation zone, on 31 Level. Also from the third oxidation zone (Gebhard, 1999).

Occurrence

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

Paragenetic and General Notes

On the type specimen (from 31 Level), johillerite occurs as radiating masses of blades and fibres to 2mm, elongated on [001]. It is associated with earlier conichalcite and cuprian adamite (Keller, 1982). The colour is a startling violet-blue.

In the third oxidation zone johillerite occurs with leiteite and cuprian adamite (Gebhard, 1999).