An art deco nephrite, chalcedony and enamel desk clock, by Ostertag. Photo: Christie's Images Ltd 2010

The black lacquer square case flanked on either side by a carved green nephrite parrot, to the two-tiered beige chalcedony and green nephrite pushpiece, the clock with gilt-finished lever movement, 17 jewels, the square red enamel dial of Chinese-inspired motif, enhanced by green, blue, pink, yellow and white flowers, with white Arabic numerals and hands, to the beige chalcedony, green nephrite and black lacquer stepped base, mounted in 18k gold, circa 1925, 8 5/8 x 6 7/8 x 3 ins., with French assay marks. Caseback signed Ostertag; inside caseback with maker's mark for Verger Frerès; case plate signed Verger, France, no. 11094; movement signed Vacheron Constantin, no. 407746  Estimate $60,000 - $80,000 Price Realized $92,500

Christie's, New York Jewels, 15 June 2010, New York, Rockefeller Plaza www.christies.com