Nové mineralogické nálezy na Sn-W ložisku Cínovec v Krušných horách (Česká republika)
Zdeněk Dvořák, Bohuslav Bureš, Pavel Škácha, Radek Škoda, Jiří Sejkora
Rare supergene minerals of the crandallite-group (florencite-(Ce), goayzite, crandallite), thometzekite and walpurgite were found at the material from abandoned Sn-W deposit Cínovec, the Krušné hory Mountains, northern Bohemia, Czech Republic. Crandallite-group minerals form strongly zoned orange to crystals up to 400 μm in cavities of quartz - cassiterite - wolframite gangue. Scheelite, clay minerals and mixite were observed in association. Thometzekite forms yellow or yellow green aggregates up to 2 mm on cavities of quartz gangue in association with segnitite, fluorite, opal and mixite. Thometzekite is monoclinic, space group C2/m, the unit-cell parameters refined from X-ray powder data are: a 9.141(12), b 6.361(5), c 7.646(8) Å, β 116.92(6) o and V 396(1) Å3. Walpurgite was found as groups of well-formed lath-like light yellow crystals up to 2 mm in the length in cavity of quartz gangue. It is triclinic, space group P-1, the unitcell parameters refined from X-ray powder data are: a 7.138(3), b 10.430(6), c 5.495(5) Å, α 101.51(5), β 110.97(4), γ 88.15(4)o and V 373.9(6) Å3. The quantitative chemical data for all described mineral phases are given.