VAVŘÍNITE, Ni2SbTe2, A NEW MINERAL SPECIES FROM THE KUNRATICE Cu–Ni SULFIDE DEPOSIT, CZECH REPUBLIC

Vavřinite, Ni 2 SbTe 2 , is a new mineral species discovered at the Kunratice Cu–Ni sulfide deposit, Czech Republic. It was observed in one polished section, where it occurs as a lath-shaped grain 20 μm long and as one additional small inclusion. Vavřinite occurs at grain boundaries between grains of pentlandite. The other associated minerals are pyrrhotite, chalcopyrite, violarite, Ni-bearing pyrite, melonite, sperrylite and altaite. In plane-polarized reflected light, the synthetic analogue of vavřinite is white-cream, weakly bireflectant, and weakly pleochroic from pale light brown to pale brown. Between crossed polars, it is anisotropic, without internal reflections. Values of reflectance in the range 400 – 700 nm are tabulated. Synthetic Ni 2 SbTe 2 has a silver grey color and metallic luster. It is brittle with a perfect {0001} cleavage. The Vickers microhardness (VHN 10 ) for synthetic Ni 2 SbTe 2 is 92 kg/mm 2 (range 73.4–111.7), which corresponds to a Mohs hardness of ~2. The calculated and measured densities are 7.88 and 7.79 g/cm 3 , respectively. The average result of three wavelength-dispersion electron-microprobe analyses of vavřinite is Ni 22.92, Fe 1.29, Pd 1.29, Sb 23.65, Bi 0.33, Te 49.95, total 99.43 wt.%, which corresponds to (Ni 1.93 Fe 0.11 Pd 0.06 ) ∑2.10 (Sb 0.96 Bi 0.01 ) ∑0.97 Te 1.93 ; synthetic Ni 2 SbTe 2 gave Ni 23.85, Sb 24.33, Te 51.77, total 99.95 wt.%, corresponding Ni 2.01 Sb 0.99 Te 2.00 (basis: five atoms per formula unit). The mineral is hexagonal, space group P 6 3 / mmc , with a 3.9090(2), c 15.6820(9) A, V 207.52(2) A 3 and Z = 2. The strongest lines in the powder-diffraction pattern of the synthetic analogue [ d in A( I ) (hkl )] are: 3.3848(13)(100), 2.8421(81)(103), 2.0704(16)(106), 1.9556(100)(110), 1.6114(23)(203), 1.2437(20)(213) and 1.1291(14)(300). The mineral is named in honor of Ivan Vavřin in recognition of his investigations of tellurium minerals and significant contributions to research on Cu–Ni sulfide deposits.