Diamond and emerald brooch by Lacloche Frères, French, c. 1927-1930. Made of white gold, platinum, emeralds, brilliant-cut diamonds and stained chalcedony. This brooch is in the shape of a stylised cypress tree. The diamonds are set against stained chalcedony to form areas of contrasting pattern and reflection. Black onyx was popular for Art Deco jewelry. It is rare in nature, so stained chalcedony was often used in its place.