Abstract: The new mineral bernardite has been identified on one specimen from Allchar, Macedonia, Yugoslavia, together with orpiment and realgar. It forms black crystals, the size of which may exceed 1 mm. The streak is deep red; on an arbitrarily oriented section R(589nm) ranges from 23.8 to 24.7% in air, from 10.2 to 11.6% in oil. Microprobe analyses together with an X-ray structure analysis suggest the ideal formula TlAs5S8, with a possible replacement of As by Sb up to 15 wt. %. Monoclinic; a 15.647(4), b 8.038(3), c 10.750(3) Å, β 91.27(3)°; space group P21/c; Z = 4; R = 0.049, wR = 0.036 for 2410 reflections. The atomic arrangement consists of a 3-dimensional As5S8 framework with eight-coordinated T1 in its holes. The mineral is named for Doc. Dr Jan H. Bernard, Prague, Czechoslovakia.