Scheelite

Scheelite


Composition: CaWO4
Crystal System : Tetragonal
Colours: Colourless, yellow, yellow-brown, orange-yellow, grey, pink
Lustre : Adamantine, greasy
Hardness (H) : 4.5-5.0
Specific Gravity (S.G) : 6.1

Distribution

Very rare. Third oxidation zone, 46 Level.

Occurrence

  • Supergene
  • 3rd Oxidation Zone

Notable Finds

Superb, brown, octahedral crystals to 5 mm were found on 46 Level, in the third oxidation zone, together with siderite and stolzite (Gebhard, 1999).

Paragenetic and General Notes

Scheelite forms a series with powellite (CaMoO4), and crystals of intermediate composition (c. 60% scheelite : 40% powellite) have been analysed recently on a specimen in the collection of Mark Feinglos (personal communication to M.Southwood, September, 2015).  These golden-brown, pseudo-octahedral crystals, to a few mm in size, are associated with quartz and fraiponite, on a sulphide matrix.

The specimen illustrated above, from 46 Level in the third oxidation zone, and in the collection of Mariusz Olesczuk, appears to be closer to end-member scheelite, with just a little molybdate indicated from semi-quantitative analysis.