Formula: Cu18Al2(AsO4)4(SO4)3(OH)24.36H2O
Compound arsenate, water content varies at room temperature based on the relative humidity. Copper mineral (Mindat)
Specific gravity: 2.67
Hardness: 2
Streak: Pale green
Colour: Blue-green to emerald green
Solubility: Soluble in acids and in ammonia.

Hydrothermal environments
Basaltic cavities

Chalcophyllite is an uncommon secondary supergene copper mineral occurring in the oxidised zones of some arsenic-bearing hydrothermal polymetallic deposits (Mindat, HOM).
Associates include azurite, malachite, brochantite, chrysocolla, spangolite, connellite, cuprite, cyanotrichite, strashimirite, parnauite, lavendulan, cornubite, langite, clinoclase, pharmacosiderite, and mansfieldite (HOM).

At the Silberberg mining district, Austria, chalcophyllite occurs with tyrolite, azurite, and brochantite (R&M 84.5.434-439).

At the El Teniente mine, Cachapoal Province, Chile, chalcophyllite has been found, often on partially corroded tennantite, associated with cornubite, connellite, goethite, gypsum, olivenite and tenorite (R&M 84.5.434-439).

At the St Jean mine, Bourgogne-Franche-Comté, France, chalcophyllite can be found on iron oxide–quartz matrix, occasionally associated with chrysocolla and mixite (R&M 84.5.434-439).

In the gold mines of the Salsigne district, Occitanie, France, chalcophyllite occurs in the oxide zone with other arsenates such as scorodite (R&M 84.5.434-439).

At the Gambatesa mine, Liguria, Italy, chalcophyllite has been reported from secondary copper assemblages on altered tennantite (R&M 84.5.434-439).

At the Scrava mine, Val Graveglia manganese district, Liguria, Italy, chalcophyllite is found associated with clinoclase, cornubite, cornwallite, lavendulan, olivenite, and tyrolite (R&M 84.5.434-439).

At the Aghbar mine, Bou Azzer district, Ouarzazate Province, Morocco, chalcophyllite has been reported on pink dolomite (R&M 84.5.434-439, MinRec 38.5.366).

At Wheal Gorland, St Day, Cornwall, England, chalcophyllite occurs in the oxide zone lining cavities with chrysocolla, cuprite, and malachite. A specimen has also been found where chalcophyllite partially replaces liroconite (R&M 84.5.434-439).

At Wheal Unity, St Day, Cornwall, England, chalcophyllite has been collected, some partially replaced by chrysocolla (R&M 84.5.434-439).

At Pemberthy Croft mine, St Hilary, Cornwall, England, UK, chalcophyllite occurs associated with arsenopyrite, chalcocite, chrysocolla, pharmacosiderite and scorodite (R&M 84.5.434-439).

At Wheal Cock, St Just, Cornwall, England, UK, chalcophyllite occurs on samples of quartz and iron oxide veins in the mine dump, associated with cornwallite and other arsenates (R&M 84.5.434-439).

At New Cliffe Hill quarry, Stanton under Bardon, Leicestershire, England, UK, chalcophyllite occurs with azurite (R&M 84.5.434-439) and chrysocolla (RES p196).

At a test mine near Dolgellau, Gwynedd, Wales, UK, chalcophyllite occurs associated with devilline, malachite, and tyrolite (R&M 84.5.434-439).

At Dyfngwm mine, Machynlleth, Powys, Wales, UK, chalcophyllite occurs associated with brochantite, langite and linarite (R&M 84.5.434-439).

Chalcophyllite occurs at Bisbee, Cochise County, Arizona, USA associated with cuprite, copper, connellite, and iron oxides, (R&M 84.5.434-439) and it is also found rarely in association with cuprite nodules (MinRec 43.1 supplement).

Chalcophyllite occurs as crystals in basaltic cavities in the Turtle Mountain area of Graham County, Arizona, USA. (R&M 84.5.434-439)

At the Majuba mine, Antelope district, Pershing County, Nevada, USA, chalcophyllite occurs in secondary copper-rich cavities in silicified rhyolite associated with azurite, brochantite, cornwallite, connellite, cuprite and spangolite (R&M 84.5.434-439).

At the Peavine district, Washoe County, Nevada, USA, chalcophyllite occurs with tyrolite on a quartz and phyllite host rock (R&M 84.5.434-439).

At the Pyramid district, Washoe County, Nevada, USA, chalcophyllite occurs with pharmacosiderite, tyrolite, and other arsenates (R&M 84.5.434-439).

At the Ajax mine and the Mammoth mine, Tintic district, Juab County, Utah, USA, chalcophyllite occurs in the oxide zone of massive sulphide deposits associated with brochantite, cornwallite, strashimirite, malachite, and chrysocolla. (R&M 84.5.434-439)


Chalcophyllite alters to chrysocolla (Mindat).

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