Diamonds may be a girl’s best friend, but shell necklaces were all the rage in the Stone Age. That’s according to researchers who have uncovered what may be the oldest jewelry ever discovered. A necklace of nacre (mother-of-pearl) and shell beads spanning 75,000 years was found at Blombos Cave in South Africa. It’s the earliest known piece of jewelry that includes both nacre and shell.

The earliest known necklaces incorporating shells were created by humans for both decorative and ceremonial purposes. In ancient Egypt, clam and tusk shell beads were common in adornment, as well as in Native American beadwork. Shells also appear in jewelry from Europe, Asia and Africa.

Today, inexpensive shell necklaces are often offered to tourists at tropical beach destinations as informal wear and souvenirs. However, the natural beauty of these mollusks is attracting many jewelers who use them to bring texture and volume to their designs.

A recent trip to Japan led to designer Silvia Furmanovich scouting for unusual materials and artisan-made crafts, which she now incorporates in her new collections of shell jewelry. “I love the way they are made and the textures and colors of their surfaces,” she says. “They are a perfect complement to our collection of organic pearls.”

Besides shells, Furmanovich also uses cowries, heishi, ambergris, opals and other gems to create her pieces. She has even used antique Japanese clam shells that feature gold leaf drawings in her earrings, and she’s paired orange spotted mitra stictica shells with three-carat Madeira citrine for a necklace. Shell necklace and bracelet