Although all the modes of hemihedrism possible in the cubic system have been found to occur among minerals, no mineral l~elonging to that system has yet been proved to be tetartohedral like sodium chlorate, and the nitrates of barium, strontium and lead.

There has, however, been some evidence in favour of the tetartohedral character of Ullmannite since the examination of the crystals from Lölling in Carinthia, and those from Sarrabus in Sardinia. The former were found by Zepharovieh to be distinctly tetrahedral in form and habit, the latter were found by Klein to be distinctly pyritohedral. Zepharorich found the specific gravity of the Lölling Ullmannite to be 6·72, while Klein found that of the Sardinian crystals to be 6·803-6·883, and for this reason it was at first thought that the two occurrences might be different modifications of the antimono-sulphide of nickel; there was also considerable discrepancy between the two analyses.