Diamond and conch pearl "Renaissance-revival" brooch, French, circa 1870. Estimate 15,000 — 20,000 USD. Lot sold 30,000 USD. Photo Sotheby's

The openwork cartouche decorated with 12 conch pearls in pastel hues of pink and peach, the center set with an old European-cut diamond of brownish color weighing approximately .95 carat, further decorated with approximately 25 old-mine diamonds in various hues including yellow, brown and pink, weighing approximately 4.00 carats, accented further with 3 seed pearls, mounted in silver and gold, assay mark. 

Sotheby's. Magnificent Jewels New York | 07 Dec 2004