Cobalt Blue

Name:
Cobalt Blue
Detailed information:

Chemistry name:	cobalt ultramarine
Properties:
Blue to green pigment of variable composition, consisting essentially of mixtures of cobalt oxide and alumina, approximating cobaltous aluminate, Co(AlO2)2. Cobalt blue is said to be the most durable of all blue pigments, being resistant to both weathering and chemicals.
Derivation:
By heating alumina with (1) cobaltous oxide, or a material yielding this oxide on calcination; (2) cobalt phosphate; (3) cobalt arsenate. Greenish shades may be made by incorporating zinc oxide.
Grade:
Technical (called genuine to distinguish it from the imitation, which is ultramarine blue).
Use:
Pigments in oil or water, cosmetics (eye shadows, grease paints).