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Formula: CuInS2
Sulphide, chalcopyrite group,
indium-bearing mineral
Crystal System: Tetragonal
Specific gravity: 4.78 calculated
Hardness: 3½ to 4
Colour: Grey
Solubility: Readily etched by concentrated nitric acid
Common impurities: Fe
Environments
Metamorphic environments
Hydrothermal environments
Minerals associated with roquesite include chalcopyrite,
bornite, cubanite,
covellite, sphalerite,
tetrahedrite,
emplectite,
wittichenite,
stannoidite, pyrite,
löllingite,
arsenopyrite, bismuth,
cassiterite, ferberite
and magnetite
(HOM).
Localities
At Mount Pleasant Mine, Saint George Parish, Charlotte Co., New Brunswick, Canada, mineralisation associated
with the Carboniferous (358.9 to 298.9 million years ago) volcanism has given rise to a
tin occurrence of complex mineralogy. The most abundant minerals are
sphalerite,
arsenopyrite, pyrite,
chalcopyrite, galena,
cassiterite and stannite;
the less abundant minerals include molybdenite,
tourmaline, wolframite,
scheelite, hematite,
tennantite, chalcocite,
digenite, covellite,
native bismuth,
bismuthinite,
wittichenite,
glaucodot, marcasite,
pyrrhotite, native gold,
siderite, goethite,
scorodite and
malachite, as well as
lead-bismuth sulphosalts and
roquesite
(AM 54.1202-1203).
At the type locality, the Charrier Mine, Laprugne, Vichy, Allier, Auvergne-Rhône-Alpes, France,
roquesite occurs as inclusions, 0.2 x 0.3 mm in size, in
bornite from the copper -
tin - iron hydrothermal deposit.
Associated minerals are chalcopyrite,
wittichenite,
chalcocite, covellite
and a little sphalerite
(AM 48.1178-1179, Mindat).
The roquesite occurs in high-temperature tin -
tungsten - bismuth -
molybdenum hydrothermal veins in highly metamorphosed rocks
(HOM).
Omodani mine, Ono City, Fukui Prefecture, Japan;
Ikuno mine, Ikuno-cho-ono, Asago City, Hyogo Prefecture, Japan;
Akenobe mine, Oya-cho, Yabu City, Hyogo Prefecture, Japan;
Fukoku mine, Fukuchiyama City, Kyoto Prefecture, Japan;
indium-tin mineralisation is
observed in the Omodani, Akenobe, Fukoku, and Ikuno deposits, which are
copper-dominant polymetallic veins of late Cretaceous to early
Tertiary age (99 to 54 million years ago or later). The
indium-tin-bearing ores are
commonly composed of roquesite, stannoidite,
sphalerite,
tennantite-tetrahedrite,
chalcopyrite and quartz,
with local bornite,
mawsonite, galena and
arsenopyrite. The iron
content of the sphalerite that coexists with roquesite,
stannoidite and
tennantite-tetrahedrite
is very low. Temperatures of formation are in the range from 285 to 310oC
(CM 29.207-215).
At the Ulsan Mine, Buk District, Ulsan, South Korea, roquesite occurs as a late-stage mineral in a
skarn iron-tungsten ore pipe
(HOM).
At the Lindbom prospect, Långban Ore District, Filipstad, Värmland County, Sweden, roquesite has been
found together with other indium-bearing sulphides associated with
magnetite in a carbonate-hosted, polymetallic sulphide
mineralisation. Roquesite occurs in indium-bearing
bornite, characteristically associated with
indium- and copper- bearing
sphalerite, as well as
chalcopyrite,
copper-bearing galena,
late-stage chalcocite -
digenite and covellite,
variable amounts of bismuth minerals, abundant
magnetite and locally
cassiterite.
Roquesite occurs as about 4 to 30 micron-sized subhedral to anhedral, often angular crystals. The
associated bornite, as well as minor
chalcopyrite, mostly exhibit low to very low
indium contents.
It is suggested that roquesite formed as a consequence of reactions between diffusion-driven
indium from sphalerite,
and the surrounding bornite, during regional metamorphism
(CM 51.629-641).
Roquesite was found in a sample from the Swedish Natural History Museum that consists of
magnetite replaced by
copper-bearing minerals, mainly
bornite and chalcocite,
which locally form intergrowths. Galena,
digenite, roquesite,
sphalerite and
native bismuth are present as small inclusions in
bornite and chalcocite.
Wittichenite has been formed as a reaction rim (up to 20
microns wide) around native bismuth.
Magnetite contains small inclusions of
chalcopyrite, bornite
and digenite. Blue-remaining
covellite is present as an alteration product.
Roquesite occurs as small roundish grains (maximum diameter 30 microns) in
bornite and chalcocite;
it is always associated with copper -
indium bearing sphalerite.
In transmitted light these sphalerite grains show irregular cores
consisting of oscillatory-zoned, darker and lighter brown
sphalerite and homogeneous rims of light yellow to colourless
sphalerite;
sphalerite grains not associated with roquesite are
entirely colourless
(CM 18.361-363).
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