Ultramarine

n. [See supra. It was so called because the lapis-lazuli was originally brought from beyond the sea—from Asia.] (Paint.) A blue pigment obtained originally by powdering the lapis-lazuli, a mineral of great beauty, and which is a silicate of soda, lime, and alumina, with a sulphuret, probably of sodium, and iron. It is the only one resembling in purity of color the blue of the prismatic spectrum. An artificial ultra-marine equal in beauty to the native, consists of silica, alumina, soda, and sodium, and is supposed to owe its color to sulphuret of sodium. Dana. Fairholt.

Ultramarine ashes (Paint.), a pigment which is the residuum of lapis lazuli, after the ultramarine has been extracted, used by the old masters as a middle or neutral tint for flesh, skies, and draperies, being of a purer and tenderer gray than that produced by mixture of more positive colors. Fairholt.