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Formula: GeS2
Sulphide of germanium
Crystal System: Monoclinic
Specific gravity: 3.05 calculated for the empirical formula, and 2.99 for the ideal formula
Streak: White
Colour: White to yellowish grey
Environments
Radvaniceite is formed under reducing conditions, via direct crystallisation from hot chlorine- and fluorine-
bearing
gasses (250–350°C), ie condensation at a depth of 30 to 60 cm under the surface of a post-coal-mining waste heap
(Mindat).
Localities
At the type locality, the Kateřina Coal Mine, Radvanice, Trutnov District, Hradec Králové Region, Czech Republic,
radvaniceite specimens were collected in an abandoned coal mine dump between 1995 and 1998. At that time,
specimens that formed from combustion were not considered to be minerals by the IMA. Recent changes by the IMA now allow
products of combustion to be considered minerals as long as the fire was started naturally and that no anthropogenic
materials were deposited in the mine.
In the case of radvaniceite, the coal fire likely started from the oxidation of
pyrite around 1967, and temperatures in the
burning dump reached up to 1000°C or more. The fire is now under control, and remediation of the mine
dump started in 1998 and was successfully completed in 2005
(AM 107.1982).
The radvaniceite occurs as aggregates resembling cotton tufts up to 5 mm in size; they are composed of acicular
crystals (somewhat resembling bent wires) up to fibres about 1–5 μm thick and up to 3 mm in length; also irregular grains,
10–50 μm, in aggregates. Associated minerals include tellurium,
teallite, stangersite,
herzenbergite, greenockite,
galena, cadmoindite and
bismuthinite
(Mindat).
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