Cobalt is one of the transition metals with chemical symbol Co and atomic number 27. It is solid and silvery-grey at normal pressure and temperature, it's very strong to cut.
Cobalt metal is another dangerous metal, do not touch without latex gloves.
We suggest this element at various purity like 99,9% and 99,99% in a 7 mL or 5mL glass vial with about 2 cm of diameter.
We usually use cobalt pellet or cobalt electrolytic flakes both very shiny.