Lot 205. Platinum, Colombian Emerald and Diamond Brooch, Marianne Ostier. Estimate 175,000 — 275,000 USD. Photo Sotheby's. The round hollow-back mixed-cut emerald measuring approximately 21.3 to 20.9 mm by 9.6 mm, framed by pear and marquise-shaped diamonds...

Cultured pearl and diamond flower brooch, Marianne Ostier, circa 1950 Designed as two flowers on curling stems, the larger set with a drop-shaped cultured pearl measuring approximately 15.0 by 13.0 mm., the petals pavé-set with numerous round diamonds,...