Zaf"fer (?), n. [F. zafre, safre; cf. Sp. zafra, safra, It. saffera, G. zaffer; all probably of Arabic origin. Cf. Zaphara.]
A pigment obtained, usually by roasting cobalt glance with sand or quartz, as a dark earthy powder. It consists of crude cobalt oxide, or of an impure cobalt arseniate. It is used in porcelain painting, and in enameling pottery, to produce a blue color, and is often confounded with smalt, from which, however, it is distinct, as it contains no potash. The name is often loosely applied to mixtures of zaffer proper with silica, or oxides of iron, manganese, etc.
[Written also
zaffre, and formerly
zaffree,
zaffar,
zaffir.]
© Webster 1913.