Bonhams’ California Jewels: A Preview of the Sept. 26 Auction

By Annie Davidson Watson | September 22, 2025

A significant event of the fall auction season comes this week, with Bonhams’ California Jewels sale on Sept. 26. Its 245 lots include signed jewels, rare gemstones, and period pieces spanning styles, from art deco to bold contemporary.

Leading the auction is a diamond necklace by the storied American jeweler Raymond Yard that holds a 5.1 ct. oval opal within a surround of diamonds and pear-shape rubies. Believed to have originally been designed as a ring, the jewel belonged to Doris Merrill Magowan, the only daughter of Merrill Lynch founder Charles Merrill.

Magowan’s husband, Safeway CEO Robert Magowan, traveled to Australia to source the opal (her favorite stone), and the couple commissioned Yard for the custom design. The necklace, which features a total of approximately 6.3 cts. diamonds and is set in platinum, carries a presale estimate of $30,000–$50,000.

Following the success of its May 20 California Jewels sale, which realized a total of over $2.1 million, Bonhams anticipates strong international interest and similarly impressive results for the upcoming auction. With its mix of historic and contemporary treasures, California Jewels underscores Bonhams’ role as a key player in the fine jewelry market.

Before live bidding commences, clients will have the opportunity to view items in the auction at Bonhams’ L.A. showroom, 7601 W. Sunset Blvd., from Sept. 23 to Sept. 25. Below are just a few highlights.