Gold has been used from the earliest times. It is yellow, lustrous and the most malleable and ductile of the metals. As a rare metal, it is used extensively for jewellery and coinage.
Gold is often applied as a decorative surface coating in the form of gold leaf for manuscript illumination, as a top layer on prepared gesso and as gold amalgam for gilding copper and silver. It is also alloyed with copper and silver to improve its mechanical properties.
As gold is resistant to corrosion it will usually only require polishing with a soft cloth.
No coating is required on pure gold but if it is alloyed with copper or silver, apply a clear acrylic or nitrocellulose lacquer to protect against tarnishing.