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Formula: KAl4(AsO4)3(OH)4.6.5H2O
Hydrated arsenate containing hydroxyl, pharmacoalumite group
Specific gravity: 2.676 calculated
Hardness: 2½
Streak: White
Colour: White, pale yellow
Luminescence: Not fluorescent in UV
Environments
Localities
The type locality is Guanaco, Taltal, Antofagasta Province, Antofagasta, Chile. Pharmacoalumite is a
secondary mineral originally found as a white incrustation
with other oxidised arsenates on a museum specimen, associated with blue
ceruleite, olivenite, green
schlossmacherite, white
mansfieldite and quartz
(AM 66.1099, Dana).
At the Aghbar Mine, Aghbar, Tansifite Caïdat, Agdz Cercle, Zagora Province, Drâa-Tafilalet Region, Morocco,
pharmacoalumite occurs as tiny white to pale pink cubic crystals, some showing phantoms, associated with
anorthoroselite, mansfieldite
and maghrebite
(Minrec 38.5.358-359).
At the Oumlil mine, Oumlil, Tansifite Caïdat, Agdz Cercle, Zagora Province, Drâa-Tafilalet Region, Morocco,
pharmacoalumite occurs as tiny white to pale pink, strontium-bearing cubic crystals, some showing phantoms,
associated with scorodite and
mansfieldite
(Minrec 38.5.358-359).
At Tamdrost-West mine, Tamdrost, Agdz Cercle, Zagora Province, Drâa-Tafilalet Region, Morocco, pharmacoalumite
forms countless tiny lustrous, greenish, cubic crystals associated with
nováčekite and zeunerite in a
body of uranium ore. Other associated minerals include erythrite,
annabergite, talmessite,
powellite, galena and native
gold
(Minrec 38.5.358-359).
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