Formula: Cu7S4
Crystal System: Orthorhombic
Specific gravity: 5.68 calculated
Hardness: 3
Streak: Black
Colour: Bluish grey

Hydrothermal environments

Anilite occurs in hydrothermal copper ores. Associated minerals include bornite, chalcopyrite, covellite and djurleite (Mindat).


At the Mount Kelly deposit, Gunpowder District, Queensland, Australia, the deposit has been mined for oxide and supergene copper ores, predominantly malachite, azurite and chrysocolla. The ores overlie primary zone mineralisation consisting of quartz - dolomite -sulphide veins hosted in dolomite-bearing siltstone and graphitic schist.
Anilite is relatively common, as sooty grey grains intimately associated with brochantite at the interface between the oxide and supergene ore horizons (AJM 22.1.19).

At Yarrow Creek, Yarrow Creek-Spionkop Creek deposit, Alberta, Canada, anilite is associated with yarrowite, spionkopite, djurleite, wittichenite, tennantite, chalcopyrite and bornite (HOM).

At the Estrella Mine, Pampa Capitana, Diego de Almagro, Chañaral Province, Atacama, Chile, anilite is associated with djurleite and covellite (HOM).

At the type locality, the Ani mine, Ani-machi, Kitaakita City, Akita Prefecture, Japan, anilite is found as prismatic or platy crystals up to 5 mm in drusy parts of the quartz vein. Most samples consist of djurleite and anilite intergrown in a definite orientation or in an epitactic relation. Djurleite was occasionally found as single crystals, and in some of the specimens anilite was the dominant constituent, with a very small amount of djurleite (AM 54.1256-1269). Another associated mineral is covellite (HOM).

At the Matsumine deposit, Odate, Akita, Japan, anilite occurs in a Kuroko ore deposit (HOM). Kuroko-type deposits consist of intimately mixed sphalerite, galena and baryte, associated (in places) with large masses of pyrite and gypsum. These deposits are a subtype of the volcanogenic massive sulphide ore deposits (Mindat).

At Rassal, Loch Kishorn, North West Highlands, Scotland, UK, a variety of copper sulphide minerals, including anilite, have been identified from a narrow vein within dolostone (JRS 15.54).

At the Baltic Mine, Baltic, Houghton county, Michigan, USA, several samples of chalcocite-bearing vein material carried small grains of anilite. The anilite seems to be restricted to quartz-rich portions of thin carbonate-quartz-sulphide veinlets, and is intimately associated with chalcocite. Additional minerals present in the veinlets include native copper, metallic grains of copper-arsenic alloys, and masses of copper arsenide phases (R&M 86-2.174).


At room temperature, djurleite, anilite and covellite are stable. Above about 70oC anilite decomposes to high digenite and covellite (AM 55.106-117).

Natural leaching of copper sulphides results in a change from djurleite to anilite to spionkopite to yarrowite to covellite. Anilite specimens leached artificially in a ferric sulphate solution show a compositional change corresponding to the change from anilite to yarrowite but do not develop the hexagonal yarrowite structure. These leached anilite specimens develop a structure similar to the pseudocubic structure of geerite (CM 19.583-591).

Back to Minerals