Title: Ultramarine
CAS Registry Number: 1317-97-1
Additional Names: C.I. Pigment Blue 29; C.I. 77007
Literature References: A blue pigment occurring naturally as the mineral lapis lazuli. Made by igniting a mixture of kaolin, Na2CO3 (or Na2SO4), S and carbon. The resulting aluminosulfosilicates resemble zeolites structurally and have the approx formula Na7Al6Si6O24S3. See: Colour Index vol. 4 (3rd ed., 1971) p 4653.
Properties: Blue lumps or powder. Insol in water; readily dec by acids, even carbonic acid, with liberation of H2S.
Use: As a pigment in calico printing, wall paper, mottled soap; bluing in laundry use; for coloring tiles, cements, rubber, but is now largely replaced by coal tar dyes; as a color in food. |