Vanadinite


Composition: Pb5(VO4)3Cl
Crystal System : Hexagonal
Colours: Orange-red, red-brown
Lustre : Sub-adamantine, resinous
Hardness (H) : 2.5-3.0
Specific Gravity (S.G) : 6.88
References: Keller (1984)

Distribution

Very rare. In the upper portions of both the first and second oxidation zones.

Occurrence

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

Notable Finds

On 28 Level, in the late 1980s, (Rob Bowell, private communication to M.Southwood, 2014)

Paragenetic and General Notes

Vanadinite is a very rare mineral at Tsumeb. Lombaard et al. (1986) note that vanadium mineralisation (chiefly as mottramite) is concentrated at the top of the first oxidation zone (between surface and 4 Level), and that there is a similar concentration at the top of the second oxidation zone.

Gebhard (1999) notes that vanadium mineralisation was restricted, essentially, to an interval between 50 m and 100 m below surface, and that brown crystals of vanadinite were found, very rarely, in that zone.

Geier (1974) observed vanadinite in the cores of descloizite aggregates. In the second oxidation zone, Rob Bowell (2014, personal communication to M. Southwood) records having collected descloizite with vanadinite on 28 Level in the late 1980s.

Vanadinite specimens from other Namibian localities have sometimes been mis-attributed to Tsumeb, and "Tsumeb" vanadinites should be regarded with caution.

Vanadinite has been reported to form pseudomorphs after the following minerals:  pyromorphite (rare, doubtful status).