Stolzite


Composition: PbWO4
Crystal System : Tetragonal
Colours: Greyish-brown, orange-yellow
Lustre : Subadamantine, resinous
Hardness (H) : 2.5-3.0
Specific Gravity (S.G) : 7.9-8.3

Distribution

Very rare. Second and third oxidation zones.

Occurrence

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

Paragenetic and General Notes

Stolzite was first recognised from Tsumeb by Foord and Conklin (1982) on a specimen acquired from Charlie Key in 1973 (labelled as anglesite).  Key believes that the specimen probably originated from 28 Level, in the second oxidation zone. A prominent, doubly-terminated tetragonal dipyramid of stolzite (25 mm), and three similar but much smaller crystals, were associated with colourless-white, prismatic quartz crystals on a tennantite matrix.

Stolzite has also been found in the second oxidation zone in association with beudantite.

Subsequently stolzite was found as thick, orange, dipyramidal crystals, to 30 mm, on 41 Level at the very top of the the third oxidation zone, and on 44 Level, as thin translucent crystals to 40 mm on quartz (Gebhard, 1999). 

Grey to black crystals of stolzite have also been found in the third oxidation zone, as well as a unique specimen with a 10 mm grey-brown stolzite crystal on hedyphane (Gebhard, op.cit.).

Stolzite is readily confused with wulfenite, and can closely resemble stottite or siderite.

Stolzite is reported to form pseudomorphs after the following minerals:  wulfenite (rare).