Conichalcite

Formula: CaCu(AsO4)(OH)
Anhydrous arsenate with hydroxyl, adelite-descloizite group, adelite subgroup. Forms a series with austinite, with cobaltaustinite, with duftite and with tangeite.
Specific gravity: 4.33
Hardness: 4½
Streak: Green
Colour: Green, yellow-green, greenish yellow; light green to yellowish green in transmitted light.
Solubility: Easily soluble in hydrochloric and nitric acids
Environments:

Hydrothermal environments

Conichalcite is a secondary mineral found in the oxidised zones of copper deposits, typically an alteration product of enargite, associated with goethite, austinite, olivenite, clinoclase, libethenite, chenevixite, brochantite, malachite, azurite and jarosite.

Localities

France

At Chessy-les-Mines, Auvergne-Rhône-Alpes, France, conichalcite occurs in cavities in sandstone associated with tyrolite.

At Valzergues, Occitanie, France, conichalcite is associated with quartz, goethite, monazite-(Ce), and agardite-(Y).

At the Cap Garonne Mine, Provence-Alpes-Côte d'Azur, France, conichalcite is associated with cerussite, olivenite, beudantite, and mimetite.

Germany
At the Clara Mine, Baden-Württemberg, Germany, conichalcite is associated with chrysocolla and cuprite.

Italy

At the San Pietro mine, Sardinia, Italy, conichalcite is associated with calcite.

Morocco

At Bou Azzer, Drâa-Tafilalet Region, Morocco, conichalcite is associated with roselite and roselite-β. At the Méchoui deposit it is associated with erythrite. At the Ightem mine, it is associated with malachite, azurite, powellite and talmessite. In the Oumlil-East open pit it is associated with chrysocolla, and at Ambed it occurs with quartz. At the Aghbar open pit conichalcite commonly encrusts grains of chalcopyrite and chalcocite, and it has also been found associated with dioptase and chrysocolla.

Namibia

At Tsumeb, Namimia, conichalcite is most commonly associated with adamite, but it is also rarely associated with smithsonite, malachite, duftite, willemite and olivenite.

Spain

At the Delfina Mine, Asturias, Spain, conichalcite is associated with azurite, cobaltarthurite, tyrolite or smithsonite.

USA

At the Bristol mine, Lincoln County, Nevada, USA, conichalcite is associated with jarosite, malachite, chrysocolla and tenorite.

Common impurities: Mg,P,V,Zn