Tangeite, (on Adamite)

Tangeite


Composition:

CaCu(VO4)(OH)

Crystal System : Orthorhombic
Colours: Moss-green, olive-green, bright-green, yellowish-green
Lustre : Vitreous, pearly
Hardness (H) : 3.5
Specific Gravity (S.G) : 3.75

 

Distribution

Very rare (?), although easily mistaken for other species.

Occurrence

  • Supergene

Paragenetic and General Notes

Tangeite was first recorded from Tsumeb by the Austrian mineralogist Franz Neuhold (http://www.mindat.org/locentry-733238.html; retrieved 19/04/015), but the method of identification was not reported.

It occurs as radial aggregates (to 0.5 mm) of yellow-green, microcrystalline needles, forming velvety, micro-botryoidal crusts.

Tangeite could be readily mistaken for conichalcite, duftite, or mottramite,and as such it could be somewhat more abundant than indicated.  The illustrated specimen was originally labelled as conichalcite with adamite, but was subsequently confirmed as tangeite after EDS and XRD analysis.