10-Carat Stone Sells for 500 Grand

At a midsummer fine jewelry auction, Bonhams had dubbed this dazzler, simply, “an impressive diamond solitaire ring.” We applaud the auction house’s restraint. We might have piled on a few more adjectives for this 10.32 ct., cut-cornered, ­colorless (F), near-flawless (VVS1) rectangular diamond—not to mention the spectacular surround of baguettes and the platinum setting. “The ring was custom-made,” says Bonhams vice president and head of U.S. jewelry Susan Abeles. “The mounting’s sole purpose was to showcase this stone.” And she wasn’t surprised by the price tag: “For a diamond to be over 10 cts. and have such fine color and clarity…the result is not only incredibly beautiful, but valuable and highly sought-after.”