Ormolu is a gold-colored alloy composed of zinc, copper, and occasionally tin in various amounts, commonly at least 50% copper. This alloy, when molten, is poured into molds, cooled and then gilded with a compound composed of mercury and powdered gold, and applied as a paste. The object is then heated to a temperature that causes the mercury to evaporate, leaving a surface with a golden appearance.
Developed in France in the mid 16th century, during the Baroque period, ormolu was used principally in decorative elements, or mounts, (things such as edges, borders, and corner guards) which would be applied to furniture, moldings, jewelry, and glass and porcelain objects.
By the beginning of the sixteenth century, ormolu was commonly used as decoration for glass object d'art, such as vases, which were made with an opaque glass that would later come to be known as "milk glass". Original milk glass objects with ormolu decorative elements, especially in unusual colors such as blue and pink, are prized by collectors and can fetch good prices at auction.
