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Formula: Cu4Al2(SO4)(OH)12(H2O)2
Hydrated sulphate, cyanotrichite group
Crystal System: Monoclinic
Specific gravity: 2.76 measured (Mindat)
Hardness: 3½ to 4
Streak: Blue
Colour: Sky blue
Solubility: Moderately soluble in hydrochloric, sulphuric and nitric acid
Environments:
Cyanotrichite is a secondary
copper mineral found sparsely in the oxidation zones of hypothermal
(high temperature)
copper-bearing ore bodies rich in aluminium and sulphate. Associated minerals include
brochantite, spangolite,
chalcophyllite,
olivenite, tyrolite,
parnauite, azurite and
malachite
(HOM).
Localities
At the Cap Garonne mine, Le Pradet, Var, Provence-Alpes-Côte d'Azur, France, cyanotrichite occurs with
chalcophyllite and parnauite
(Dana).
Cyanotrichite from Cap Garonne - Image
At the Khder Mine, Ouisselsate Caïdat, Amerzgane Cercle, Ouarzazate Province, Drâa-Tafilalet Region, Morocco,
cyanotrichite forms pale blue crusts on vein quartz,
with many other secondary
copper minerals
(Minrec 38.5.371).
The type locality is the Moldova Nouă Mine, Moldova Nouă-Sasca Cu-Mo ore field, Caraş-Severin, Romania.
Cyanotrichite from the Moldova Nouă Mine -
Image
At the Tintic Mining District, Juab County, Utah, USA, rare pale blue sprays of cyanotrichite have been found
at the Mammoth and nearby Gold Chain mines. It occurs in a matrix of quartz
with clinoclase,
conichalcite, cornwallite,
partially altered enargite,
pharmacosiderite, pyrite
and tyrolite.
(MinRec 55.2.198).
Cyanotrichite from Tintic - Image
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