Cobalt
![](/Images/godic/202501/02/Kobalt_electrolytic_and_1cm3_cube0902.jpg")
![A block of electrolytically refined cobalt (99.9% purity) cut from a large plate](/Images/godic/202501/02/Kobalt_13g0902.jpg")
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![Early Chinese blue and white porcelain, manufactured c. 1335](/Images/godic/202501/02/Early_blue_and_white_ware_circa_1335_Jingdezhen0902.jpg")
Cobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt in the Earth's crust is found 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.