Formula:CuPb2(MoO4)(AsO4)(OH)
Compound molybdate and arsenate
Crystal System: Monoclinic
Specific gravity: 6.57 measured, 6.6 calculated
Hardness: 2 to 3
Streak: Yellow
Colour: Light green
Environments
Molybdofornacite is a very rare arsenic mineral.
Localities
At the type locality, the Tsumeb Mine, Oshikoto Region, Namibia, molybdofornacite was found as minute crystals on
a dioptase specimen in the deep oxidation zone of a
dolostone-hosted hydrothermal polymetallic ore deposit. It is the
latest oxidation product in the association which also includes calcite,
quartz, limonite and
duftite (AM 69.567). Associated minerals include
dioptase, duftite,
wulfenite, quartz,
calcite and hematite
(HOM).
At the Tonopah-Belmont mine, Arizona, USA, molybdofornacite has been found associated with
wulfenite and pyromorphite
(HOM).
At the Bullfrog #2 claim, New Mexico, USA, molybdofornacite has been found associated with
mimetite, descloizite,
willemite, chrysocolla and
hematite
(HOM).
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