Anorthoroselite

anorthoroselite

talmessite

roselite

wendwilsonite

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Formula: Ca2Co(AsO4)2.2H2O
Hydrated normal arsenate, fairfieldite group, triclinic paramorph of monoclinic roselite, cobalt-bearing mineral, forms a series with talmessite
Crystal System: Triclinic
Specific gravity: 3.71
Hardness: 3½ to 4
Streak: Pale red
Colour: Dark rose red, dark pink
Common impurities: Mg
Environments

Hydrothermal environments

Anorthoroselite is a rare secondary mineral in cobalt-bearing hydrothermal mineral deposits (HOM).

Localities

At Dome Rock Copper Mine, Boolcoomatta Reserve, Olary Province, South Australia, anorthoroselite is associated with erythrite, arthurite, conichalcite, chenevixite, scorodite, cobaltaustinite and heterogenite (HOM).

At the type locality, Schneeberg, Erzgebirgskreis, Saxony, Germany, anorthoroselite occurs as granular masses associated with pale pink cobalt-bearing calcite and a few grains of dark rose-coloured roselite, in vein material consisting principally of quartz and pyrite. All of the minerals appear to be primary hydrothermal deposits (AM 40.832-833)

At the Bou Azzer mining district, Drâa-Tafilalet Region, Morocco, anorthoroselite and talmessite are almost indistinguishable from each other. They are rare world-wide but widespread here, occurring rarely as free-standing crystals to 1 cm in size, and more commonly as rounded clusters, subparallel aggregates and coral-like spherules. Crystals of anorthoroselite with talmessite cores have been found resting on a dolomite matrix associated with wendwilsonite, and epitactic intergrowths of anorthoroselite and roselite have been found in cavities in dolomite associated with cobaltlotharmeyerite and cobaltaustinite (Min Rec 38-5.393).

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