Smaltite
Clades: Arsenides.
Chemical: (Co,Fe,Ni)As2; cobalt, iron, nickel, and arsenide.
Color: tin-white to steel-grey; streak is greyish black.
Lustre: metallic.
Hardness: 5.5.
Specific gravity: 6.5.
Mineralogy
Smaltite is a variety of the mineral skutterudite.
Crystal structure: cubic; hemihedral symmetry; form of cubes or cubo-octahedra, but imperfectly developed.
More often the mineral is found as compact or granular masses.
Related: Chloanthite is isomorphous species, NiAs2.