Mansfieldite, (w. Scorodite)

Mansfieldite


Composition:

AlAsO4 ยท 2H2O

Crystal System : Orthorhombic
Colours: White, pale-yellow, light gray; colourless in transmitted light.
Lustre : Vitreous
Hardness (H) : 3.5
Specific Gravity (S.G) : 3.02

 

Distribution

Extremely rare. Probably second oxidation zone.

Occurrence

  • Supergene
  • 2nd Oxidation Zone

Paragenetic and General Notes

Mansfieldite is the aluminium analogue of scorodite, with which it forms a series.

At Tsumeb, pale-yellow mansfieldite has been confirmed as forming the cores of green zoned crystals of aluminium-rich scorodite on a specimen in the W. (Bill) Pinch collection (Bill Pinch, personal communication to M. Southwood, February 2015).