Summary: A new cobalt-iron mineral of composition close to CoFe has been found associated with awaruite (Ni₃Fe) in the Red Hills serpentinites of the Wairau Valley, South Island, New Zealand. The name wairauite, after this locality, is proposed. Electron-probe analysis of the small grains so far discovered has shown that the nickel content is very low (0·5 ± 0·1 wt. %). Wairauite is optically very similar to awaruite but a tendency to form euhedral grains (octahedron and cube) and a slightly lower refiectivity are an aid to identification. No X-ray data are available at present, but it is suggested that the structure may correspond to that of the ordered CsCl type of the synthetic alloy of the same composition.