Metals

Gold

Gold has been used from the earliest times. It is yellow and lustrous, and the most malleable and ductile of all metals. As it is a rare metal, it has been used for jewellery and coinage.

Gold is often applied as a decorative surface coating—in the form of gold leaf for manuscript illumination and for gilt frames or tempera/fresco paintings, and as gold amalgam for gilding copper and silver. It is also alloyed with copper and silver to improve its mechanical properties.

Treatment of gold

Because gold is very resistant to corrosion, it usually requires only polishing with a soft cloth. No coating is required on pure gold; but if it is alloyed with copper or silver, a clear acrylic or nitrocellulose lacquer gives protection against retarnishing.

Gold/silver watch from the wreck of the Pandora, before treatment. Photograph courtesy of the Western Australian Museum

Watch after treatment Photograph courtesy of the Western Australian Museum