Images
Formula: Pd3Ag2S
Sulphide, palladium-bearing mineral
Crystal System: Isometric
Specific gravity: 9.90 calculated
Colour: White with a light pinkish brown tint
Common impurities: Fe
Environments
Localities
The type locality, the Marathon deposit, Coldwell complex, Thunder Bay District, Ontario, Canada, is a
copper -
platinum group elements
- gold deposit, disseminated in
gabbro.
The platinum group minerals are associated with
chalcopyrite, bornite and
pyrrhotite, all of which occur interstitially to
plagioclase, clinopyroxene
and olivine, or are intergrown with
secondary minerals such as
chlorite group minerals,
actinolite, and minor
serpentine and calcite.
Coldwellite was found in a heavy-mineral concentrate together with other minerals, including
hollingworthite,
isoferroplatinum,
keithconnite, kotulskite,
mertieite, michenerite,
palladoarsenide,
sobolevskite, sperrylite,
stillwaterite and
vysotskite. Other heavy minerals include
titanium- and chromium- rich
magnetite, ilmenite,
pyrrhotite, chalcopyrite
and pentlandite, with trace amounts of
bornite, cobaltite and
galena. The major gangue minerals
are plagioclase, augite,
actinolite, olivine
and chlorite, with minor to trace
serpentine, biotite and
talc
(CM 53.845-857).
Back to Minerals