Source : Webster's Revised Unabridged Dictionary (1913)

Ultramarine \Ul`tra*ma*rine"\, n. [Cf. Sp. ultramarino. So
   called because the lapis lazuli was originally brought from
   beyond the sea, -- from Asia.] (Chem.)
   A blue pigment formerly obtained by powdering lapis lazuli,
   but now produced in large quantities by fusing together
   silica, alumina, soda, and sulphur, thus forming a glass,
   colored blue by the sodium polysulphides made in the fusion.
   Also used adjectively.

   {Green ultramarine}, a green pigment obtained as a first
      product in the manufacture of ultramarine, into which it
      is changed by subsequent treatment.

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