WENDWILSONITE

Ca2(Mg,Co)(AsO4)2·2H2O

Wendwilsonite was described by Dunn et al. (1987a) from Sterling Hill, Morocco, and Mexico. It is rare locally and has not been found at Franklin. Wendwilsonite is bright pink and occurs as euhedral 0.5 mm crystals with vitreous luster and a perfect cleavage on {010}. The extreme paucity of material precluded the measurement of other physical and optical properties on local material; they are likely very close to those reported for Moroccan wendwilsonite by Dunn et al. (1987a). Both chemical and X-ray methods are required for verification. Wendwilsonite is a calcium magnesium arsenate hydrate mineral and the Mg-analogue of roselite. A microprobe analysis is given in Table 25. Even small amounts of cobalt color the mineral intensely. Wendwilsonite is named in honor of Dr. Wendell E. Wilson, editor and publisher of The Mineralogical Record, in recognition of his contributions to specimen mineralogy.

Hardness: 3-4 Other characteristics.