Art Nouveau opal, seed pearl and diamond collier de chien, circa 1900. Photo courtesy Sotheby's

Each plaque depicting grape vines composed of carved opal, highlighted with circular-, single-cut and rose diamonds, separated by four rows of seed pearl torsades, length approximately 355mm. 

Provenance: Jewels from the Collection of Odile de Richelieu, Countess Gabriel de La Rochefoucauld, Princess de La Rochefoucauld (1879-1974). 

Litterature: Cf: Sigrid Barten, René Lalique, Bonn, 1989, pages 221 and 225, for necklaces of similar design by René Lalique.

This style of pearl and gem-set colliers de chien, wide choker-style necklaces, were very much in vogue from the late 19th century through the first World War.