Mottramite

Mottramite


Composition: PbCuVO4(OH)
Crystal System : Triclinic
Colours: Green, brown, black
Lustre : Greasy, vitreous
Hardness (H) : 3.0-3.5
Specific Gravity (S.G) : 5.9-6.4
References: Keller (1977a)

Distribution

Common. First, second, and third oxidation zones.

Occurrence

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

Paragenetic and General Notes

Recognised very early in Tsumeb's history (Maucher, 1908), mottramite occurred extensively in the upper portions of both the first and second oxidation zones (Keller, 1977). Typically as radially-structured masses, sometimes dendritic, or as moss-like coatings; single crystals of acicular habit are rare.

Readily confused with duftite.

Mottramite is reported to form pseudomorphs after the following minerals: calcite (rare), tennantite (rare), wulfenite (rare).