The di-antimonide, FeSb₂

The di-antimonide, FeSb₂, is obtained in an analogous manner, and occurs as crystals in raw antimony obtained in the commercial extraction of this metalloid.

It crystallises according to the rhombic system, the axial ratios being

a: b: с = 0.75909: 1: 0.96872.

It melts at 732° C., and at that temperature undergoes partial decomposition into triferro di-antimonide, Fe₃Sb₂: -

3FeSb₂ ⇔ Fe₃Sb₂ + 4Sb.