Bronze d'oré, also known as ormolu or gilt bronze, was a decorative finish used on luxury furnishings in the 18th and 19th centuries. An application of finely ground high carat gold and mercury amalgam was placed on objects of bronze. When subjected to extremely high heat, the mercury evaporated, leaving behind a lustrous coating of gold.

 

Bronze may be patinated in two manners – through firing at a foundry or via the application of colors, varnishes and waxes outside of the oven.  It can also occur as a natural process of oxidation.