Reference:
▪ Škácha, P., Sejkora, J., Plášil, J. (2018): Bytízite, a new Cu-Sb selenide from Příbram, Czech Republic. Mineralogical Magazine, 82, 199-209.
Abstract:
The new mineral bytízite was found in the dump of shaft No. 16, one of the mines in the Příbram uranium and base-metal district, central Bohemia, Czech Republic. Bytízite is associated with chaméanite, příbramite, giraudite, berzelianite, umangite, eskebornite, hakite, tetrahedrite, bukovite, crookesite and uraninite in a calcite-dominant gangue. The new mineral occurs as anhedral grains up to 40 μm, growing together in aggregates up to 300 μm across in the calcite gangue. Bytízite is steel-grey in colour and has a metallic lustre. Mohs hardness is ca. 2-3; the calculated density is 6.324 g.cm-3. In reflected light bytízite is grey with a yellowish hue, yellowish and brownish. Bireflectance and pleochroism are weak. Anisotropy is strong with grey to brownish rotation tints. Internal reflections were not observed. The empirical formula, based on electron-microprobe analyses, is (Cu3.00Fe0.01Ag0.01)3.02(Sb0.97As0.06)1.03Se2.94. The ideal formula is Cu3SbSe3, which requires Cu 34.71, Sb 22.16 and Se 43.13, total 100.00 wt.%. Bytízite is orthorhombic, Pnma, a = 7.9594(12), b = 10.5830(14), c = 6.8240(11) Å, with V = 574.82(15) Å3 and Z = 4. The strongest reflections of the calculated powder X-ray diffraction pattern [d, Å (I)(hkl)] are: 3.73(37) (210), 3.27(62) (211), 2.867(40) (022), 2.698(100) (122), 2.646(37) (040). According to the single-crystal X-ray 25 diffraction data (Robs = 0.0437), bytízite is isostructural with synthetic Cu3SbSe3. The structure of bytízite contains two Cu, one Sb, and two Se sites (last mentioned is occupied both by Se and S atoms). In the structure of both synthetic Cu3SbSe3 and bytízite, there are groups of three cis-edge-sharing tetrahedra [Cu3Se8], which are interlinked to a 3D framework by SbSe3 groups. Bytízite is named after its type locality, the Bytíz deposit, near the village Bytíz.
▪ Škácha, P., Sejkora, J., Plášil, J. (2018): Bytízite, a new Cu-Sb selenide from Příbram, Czech Republic. Mineralogical Magazine, 82, 199-209.
Abstract:
The new mineral bytízite was found in the dump of shaft No. 16, one of the mines in the Příbram uranium and base-metal district, central Bohemia, Czech Republic. Bytízite is associated with chaméanite, příbramite, giraudite, berzelianite, umangite, eskebornite, hakite, tetrahedrite, bukovite, crookesite and uraninite in a calcite-dominant gangue. The new mineral occurs as anhedral grains up to 40 μm, growing together in aggregates up to 300 μm across in the calcite gangue. Bytízite is steel-grey in colour and has a metallic lustre. Mohs hardness is ca. 2-3; the calculated density is 6.324 g.cm-3. In reflected light bytízite is grey with a yellowish hue, yellowish and brownish. Bireflectance and pleochroism are weak. Anisotropy is strong with grey to brownish rotation tints. Internal reflections were not observed. The empirical formula, based on electron-microprobe analyses, is (Cu3.00Fe0.01Ag0.01)3.02(Sb0.97As0.06)1.03Se2.94. The ideal formula is Cu3SbSe3, which requires Cu 34.71, Sb 22.16 and Se 43.13, total 100.00 wt.%. Bytízite is orthorhombic, Pnma, a = 7.9594(12), b = 10.5830(14), c = 6.8240(11) Å, with V = 574.82(15) Å3 and Z = 4. The strongest reflections of the calculated powder X-ray diffraction pattern [d, Å (I)(hkl)] are: 3.73(37) (210), 3.27(62) (211), 2.867(40) (022), 2.698(100) (122), 2.646(37) (040). According to the single-crystal X-ray 25 diffraction data (Robs = 0.0437), bytízite is isostructural with synthetic Cu3SbSe3. The structure of bytízite contains two Cu, one Sb, and two Se sites (last mentioned is occupied both by Se and S atoms). In the structure of both synthetic Cu3SbSe3 and bytízite, there are groups of three cis-edge-sharing tetrahedra [Cu3Se8], which are interlinked to a 3D framework by SbSe3 groups. Bytízite is named after its type locality, the Bytíz deposit, near the village Bytíz.