Images
Formula: Ag15Cu(Sb,As)2S7Te4
Sulphosalt, pearceite-polybasite group,
silver-, copper-,
antimony-, arsenic- and
tellurium- bearing mineral
Crystal System: Trigonal
Specific gravity: 7.76 calculated
Hardness: 3
Colour: Dark grey, black
Common impurities: Cu
Environments
Localities
At the type locality, the Bambollita Mine, Moctezuma, Moctezuma Municipality, Sonora, Mexico, benleonardite
occurs in ore specimens collected from the dumps of the disused mine. It is found in fractures in an intensely
silicified rhyolitic
vitrophyre. The associated minerals are
acanthite, hessite,
cervelleite, pyrite,
sphalerite and native silver.
Together with benleonardite, these form thin black crusts in fractures filled with
quartz and dolomite in highly
altered, tuffaceous,
andesitic and
rhyolitic rocks
(MM 50.681-686).
Benleonardite from the Bambollita Mine -
Image
At the Geis Mine, Cone Butte Sub-District, Warm Springs District, Fergus County, Montana, USA, benleonardite
occurs in an epithermal gold -
silver - tellurium
vein system along the contact between alkaline intrusives and sediments. Associated minerals include
hessite and tetrahedrite
(HOM).
At the Mayflower prospect, Norwegian Mining District, Madison County, Montana, USA, benleonardeite occurs
in a limestone-hosted disseminated
gold -
silver - tellurium
deposit, associated with tetrahedrite,
hessite, gold and
sphalerite
(HOM).
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