Mosaic gold

A recipe for mosaic gold is already provided in the 3th century A.D. treatise Baopuzi, composed by the Chinese alchemist Ge Hong.

[5] The earliest sources for its preparation in Europe, under the name porporina or purpurina, are the late 13th-century North Italian Liber colorum secundum Magistrum Bernardum and Cennino Cennini's Libro dell'arte from the 1420s.

[6] Instructions became more widespread and varied thereafter,[7] the around 1500 recipe collection Liber illuministarum from Tegernsee Abbey in Bavaria alone offering six different methods for its preparation.

[8] Alchemists prepared it 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.