|
Ultramarine is a blue pigment consisting primarily of a double silicate of aluminium and sodium with some sulfides or sulfates, and occurring in nature as a proximate component of lapis lazuli. In the past, it has also been known as azzurrum ultramarine, azzurrum transmarinum, azzuro oltramarino, azur d'Acre, pierre d'azur, Lazurstein. Current terminology for ultramarine include natural ultramarine (English), outremer lapis (French), Ultramarin echt (German), oltremare genuino (Italian), and ultramarino verdadero (Spanish). The pigment color code is P. Blue 29 77007. Ultramarine is the most complex of the mineral pigments, a complex sulfur-containing sodio-silicate (Na8-10Al6Si6O24S2-4), essentially a mineralized limestone containing a blue cubic mineral called lazurite (the major component in lapis lazuli). Some chloride is often present in the crystal lattice as well. The blue color of the pigment is due to the S3− radical anion, which contains an unpaired electron.
|
|
RSS