Tricobalt Tetraselenide, Co₃Se₄

Tricobalt Tetraselenide, Co₃Se₄, is obtained in the crystalline form by heating cobalt chloride to dull redness in a mixture of hydrogen selenide or chloride in nitrogen. The resulting crystals are minute regular octahedra, violet-grev in colour and isomorphous with linnaeite, Co₃S₄. Density 6.54 at 15° C.