Images
Formula: Cu2+(AsO3OH).H2O
Hydrated hydrogen arsenate
Crystal System: Triclinic
Specific gravity: 3.70 measured, 3.63 calculated
Hardness: 3 to 3½
Streak: Pale green
Colour: Light green to sea green
Solubility: Soluble in dilute hydrochloric acid
Environments
Geminite occurs as coatings on quartz
(Webmin).
Localities
At the Salsigne mine, Salsigne, Carcassonne, Aude, Occitanie, France, geminite occurs on specimens from mine dumps at the
gold-bearing arsenic sulphide deposit, associated with
lindackerite, yvonite,
arsenopyrite, bismuth,
chalcopyrite and pushcharovskite
(HOM).
At the type locality, Cap Garonne Mine, Le Pradet, Var, Provence-Alpes-Côte d'Azur, France, geminite occurs on
quartz in an arsenic-bearing oxidised lead-copper deposit. Associated minerals include
tennantite, covellite,
chalcanthite, lavendulan,
pushcharovskite, antlerite and
brochantite
(AM 77.671, HOM).
At the Khder Mine, Amerzgane, Ouarzazate Province, Drâa-Tafilalet Region, Morocco, geminite has been found as typical twins to
0.5 mm in a weathered piece of löllingite which mainly contained
scorodite crusts and spherules of schneiderhöhnite
(Minrec 38.5.375).
Back to Minerals