Cobalt are faced by cobalt miners. Cobalt can be effectively absorbed by charred pigs' bones; however, this process is inhibited by copper and zinc, which have greater affinities to bone char. Cobalt Cobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt is found in the Earth's crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal. Cobalt-based blue pigments (cobalt blue) have been used since ancient times for jewelry and paints, and to impart a
Cobalt sulfide Cobalt sulfide Cobalt sulfide is the name for chemical compounds with a formula CoS. Well-characterized species include minerals with the formula CoS, CoS, CoS, and CoS. In general, the sulfides of cobalt are black, semiconducting, insoluble in water, and nonstoichiometric. Cobalt sulfides occur widely as minerals, comprising major sources of all cobalt compounds. Binary cobalt sulfide minerals include the cattierite (CoS) and linnaeite (CoS). CoS (see image in table) is isostructural with iron pyrite, featuring disulfide groups, i.e. CoS. Linnaeite, also rare, adopts the spinel motif. The CoS compound is known as a very rare cobaltpentlandite (the Co analogue of