Epitactic Overgrowth of Hinsdalite on Corkite Hemispheres

Epitactic Overgrowth of Hinsdalite on Corkite Hemispheres
Epitactic Overgrowth of Hinsdalite on Corkite Hemispheres. Photo credit: Matthias Reinhardt

Epitactic overgrowth of hinsdalite (white) on corkite (yellow), hemispheres.

Hinsdalite
A trigonal-hexagonal scalenohedral mineral containing aluminum, hydrogen, lead, oxygen, phosphorus, strontium, and sulfur.

Hinsdalite
Formula: PbAl3(PO4)(SO4)(OH)6
Color: Colorless, greenish, pearly white
Lustre: Vitreous, Greasy
Hardness: 4½


Corkite is a phosphate mineral in the beudantite subgroup of the alunite group. Corkite is the phosphate analogue of beudantite and with it, a complete solid solution range exists. Corkite will also form a solid solution with kintoreite.

Color: Brown to light yellowish brown, pale yellow, yellowish green to dark green
Mohs scale hardness:  3.5 - 4.5
Luster: Vitreous, resinous
Corkite is named after County Cork, Ireland; the location where the first notable amount was discovered in 1869.

The specimen in the photo is from: Schöne Aussicht Mine, Dernbach, Neuwied, Wied Iron Spar District, Westerwald, Rhineland-Palatinate, Germany
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