Record details

    Natural SnGeS3 from Radvanice near Trutnov (Czech Republic): its description, crystal structure refinement and solid solution with PbGeS3
Statement of responsibility
    Jiří Sejkora, Peter Berlepsch, Emil Makovicky, Tonči Balić-Žunić
    Balić-Žunić, Tonči
    Berlepsch, Peter
    Makovicky, Emil
    Sejkora, Jiří, 1968-
Source title - serial
    European journal of mineralogy
    Vol. 13, no. 4
    p. 791-800
    5 obr., 2 fot., 8 tab., 21 bibl.
    Zkr. název ser.: Eur. J. Mineral.
Subject group
    chemismus minerálů
    minerály hořící haldy
    minerály supergenní
    roztok pevný
    vnitrosudetská pánev
    zpřesňování struktury
Geographical name
    Radvanice (Trutnov)
Abstract (in english)
   Natural SnGeS3 is monoclinic, with space group P21/c and with a = 7.2704(15)A, b = 10197(2)A, c = 6.8463(14)A, á = 105.34(3)ř, V = 489.5 A3, a:b:c = 0.7130:1:0.6714, Z = 4 and Dcalc = 3.98 g/cm3. The strongest lines in the X-ray powder diffraction pattern are (d in A/I/I0 (hkl)) : 7.006/100 (100), 4.135/49 (120), 3.077/47 (130), 2.776/38 (022), 2.699/69 (211), 2.121/31 (320), 1.724/35 (41-2). it forms transparent, elastic and flexible flattened acicular crystals with cross-section 2-5 x 20-40 um and up to 1 cm in the length, which produce random or fan-shaped clusters on rock fragments and on black crumbly ash. It has an orange to yellowish red colour, very light yellowish brown streak, vitreous to adamantine lustre; VHN 10g microhardness is 55 kp/mmř (539 MPa); two types of perfect cleavage were established - perpendicular or oblique to elongation. No fluorescence at 254 and 366 nm of UV light was observed.
   In reflected light SnGeS3 is light grevish white with distinct orange brown internal reflections, anisotropic rotation tints are from dark brownish grey to reddish brown or brownnish violet. Chemical analysis yields an average composition of Sn 40.47, Pb 0.29, Ge 22.73, Fe 0.03, Bi 0.27, Sb 0.10, As 0.10, S 31.42, Se 2.62, total 98.03 wt.%, leading to an empirical formula Sn 1.02 Ge 0.94 (S 2.93 Se 0.10) 0.03. SnGeS3 was also observed in multicomponent aggregates on which the above described acicular crystals grow. Phases of the SnGeS3-PbGeS3 series in these aggregates from irregular grains 2-100 um size with a more variable composition
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    15. 8. 2007
Import date
    8. 8. 2012