Ruby and diamond brooch, circa 1900. Estimate 39,000 — 59,000 CHF (36,793 - 55,660 EUR). Photo Sotheby's

Designed as a bat, the wings pavé-set with circular-cut rubies and diamonds, the eyes composed of marquise-shaped diamonds, French assay and maker's mark, likely by Aucoq, fitted case signed A. Aucoq.

Bibliography: Cf: Henri Vever, La Bijouterie Français au XIXe Siècle (1800-1900), Vol. 3, Paris, 1908, pg. 576 for a brooch of similar design by Camille Gueyton.

Sotheby's. Magnificent Jewels and Noble Jewels, Genève, 12 mai 2015, 10:30 AM