Vanackerite


Composition: Pb4Cd(AsO4)3(Cl,OH)
Crystal System : Trigonal
Colours: Pale-yellow
Hardness (H) : c.4
Specific Gravity (S.G) : 7.28
Year of Discovery: 2011
IMA Number: 2011-114
IMA Status: Approved

Tsumeb is the Type Locality

Distribution

Very rare (?). Second oxidation zone.

Occurrence

  • Supergene
  • 2nd Oxidation Zone

Paragenetic and General Notes

Related to apatite group structures, vanackerite is a cadmium-substituted derivative of mimetite. The type specimen was collected in 1980 from the second oxidation zone, by Tsumeb mineralogist John Innes, and was mistaken for mimetite. 

Vanackerite occurs as light yellow rosettes of thin pseudohexagonal tabular crystals up to 5 mm in size on bluish green thometzekite. Further associated minerals are anglesite and gypsum. 

Vanackerite shows orange fluorescence under ultraviolet light, with the strongest response at a wavelength of 366 nm. Crystals are tabular on {0001}, with {01-10}, {11-21} and {10-11} also present.