What is "mosaic gold"

ormolu \or`mo*lu"\ ([^o]r`m[-o]*l[udd]"), n. [F. or moulu; or gold (L. aurum) + moulu, p. p. of moudre to grind, to mill, L. molere. See Aureate, and Mill.] A variety of brass made to resemble gold by the use of less zinc and more copper in its composition than ordinary brass contains. Its golden color is often heightened by means of lacquer of some sort, or by use of acids. Called also mosaic gold.

ormolu varnish, a varnish applied to metals, as brass, to give the appearance of gold.

n. Powdered stannic sulfide (SnS₂) used as a pigment in gilding

n. a yellow pigment sometimes suspended in lacquer [syn: stannic sulfide]

Mosaic gold or bronze powder refers to tin(IV) sulfide as used as a pigment in bronzing and gilding wood and metal work. It is obtained as a yellow scaly crystalline powder. The alchemists referred to it as aurum musivum, or aurum mosaicum. The term mosaic gold has also been used to refer to ormolu and to cut shapes of gold leaf, some darkened for contrast, arranged as a mosaic. The term bronze powder may also refer to powdered bronze alloy.

Alchemists prepared this by combining mercury, tin, sal ammoniac, and sublimated sulfur (fleur de soufre), grinding, mixing, then setting them for three hours in a sand heat. The dirty sublimate being taken off, aurum mosaicum was found at the bottom of the matrass. It was recommended in most chronic and nervous cases, and particularly convulsions of children; however, it is no longer recommended for any medical uses.