Also called kupfernickel, a coppery-red
ore of nickel with an easily tarnished metallic
luster. It consists of nickel arsenide (NiAs) and is often found in veins
with some cobalt, iron, and sulfur, notably pyrrhotite.
It crystallizes in the hexagonal system generally in columnar masses, rarely
as tabular crystals. Hardness: 5–5.5; relative density 7.8.
AND PLANETARY SCIENCE