What is "spherocobaltite"

n. (context mineralogy English) cobalt(II) carbonate, a red trigonal mineral used in pottery glazes.

Spherocobaltite or sphaerocobaltite is a cobalt carbonate mineral with chemical composition CoCO. In its (rare) pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. It crystallizes in the trigonal crystal system.