Tahitian Black Pearl and Diamond Ring. Photo courtesy M.S.Rau Antiques.

A monumental 17.2mm Tahitian black pearl showcases its mesmerizing beauty in this ring. Attended to by 1.90 carats of white diamonds in its 18K white gold setting, this pearl displays the peerless depth and glow accomplished through the unusually thick nacre for which these gems of the sea are coveted. Prized for their luminous coloring, black pearls hailing from the warm waters of the South Pacific are among the most beautiful in the world. Farmed from the large French Polynesian Black-Lip pearl oyster (Pinctada margaritifera), these pearls possess the darkest, most vibrant coloring of any other pearl. Price: $14,850

M.S.Rau Antiques.