All that Glitters: The Alchemy of French Ormolu
Gold has long been one of the most sought-after minerals on earth. Over the millennia, civilizations have worked with this highly-coveted material whose intrinsic value limited its production to only the wealthiest members of society. The invention of the process of gold plating, also known as mercury gilding, allowed for a broader audience and consumer.
Under the royal court of Louis XIV, the gilding technique known as Ormolu as was elevated to an art form. Ormolu mounts found their way on to furniture, clocks, lighting fixtures, as well as heightening rare Asian porcelains and lacquers. Ormolu was admired for its durable and glistening finish, and its ability not to tarnish. The word Ormolu comes from the combination of two French words: Or, meaning ‘gold’, and Moulu, meaning ‘grounded/pounded’.
The manufacture of true Ormolu uses the process of mercury gilding, or fire gilding. The process is dangerous and complex, mixing pure gold together with a liquid mercury to form a paste-like amalgam. The amalgam is brushed onto a three-dimensional surface of silver, copper, brass or bronze. The object is then heated in a furnace until the mercury is vaporized. The mercury is driven off by the heat, leaving the gold securely bonded to the surface of the object. The final step is to burnish, or polish, the object with an agate tool. This dangerous process was outlawed in France around 1830 due to the toxicity of the mercury vapors. A French gilder in the 18th century rarely lived past the age of forty.
Workshops continued to employ mercury gilding until 1900, with a few continuing its use until the mid-20th century. To avoid using mercury, alternative gilding techniques were developed, including electroplating which was used from the mid-19th century through the present day.