18 karat gold, titanium, pink sapphire and diamond  flower brooch, Margherita Burgener.  Photo Sotheby's

The stylized flowerhead set in the center with a cascade of rose-cut pear-shaped pink sapphires weighing 16.16 carats, accented by round diamonds, the petals composed of purple anodized titanium bordered by small round diamonds, the total diamond weight approximately 4.70 carats, signed Margherita Burgener, maker's mark, numbered 28830111. With signed box. Lot 36. Estimate 15,000-20,000 USD

Sotheby's. Magnificent Jewels. New York | 18 avr. 2012, 10:00 AM www.sothebys.com