Cobalt is a silver-gray magnetic metal similar to iron and nickel in appearance, but harder and stronger. Cobalt is used in high-temperature creep-resistant super alloys, hard facing and wear-resistant alloys, high-speed steels, tool steels and other steels as well as in cobalt-base tool materials, electrical-resistant alloys, and special expansion and constant-modulus alloys.

Cobalt is an important trace element in soils and is necessary for animal nutrition. Cobalt has unusual coordinating properties, especially the trivalent ion. Cobalt has three radioactive isotopes: cobalt 57, 58 and 60. These radioisotopes are used for biological and medical research.

Crystal Structure: α phase, close-packed hexagonal, hP2 (P6₃/mmc); a = 0.25071 nm, c = 0.40686 nm.

                              β phase, face-centered cubic, cF4 (Fm3m); a = 0.35441 nm,

Atomic Weight:                 58.94

Specific Gravity:               8.832 gm/cc for α phase; 8.80 gm/cc for β phase

Boiling Point:                    2900 ^oC

Heat of Fusion:                 3.64

Specific Heat Capacity:     0.099

Hardness:                          cast, 124 Brinell; electro-deposited, 300 Brinell

Workability:                     Annealed cobalt strip can be cold rolled to about 25% reduction in area between intermediate anneals.