Diamond Oyster Shell Necklace Set. Oyster Set Necklace includes beaded necklace with white beads on 6 strands with Oyster pendants in diamond shape (Square shape). Stunning and great for a gift or special someone. Polished Shell pendant is approx 2 1/2 inches by 2 1/2 inches. Hand made. Necklace approx 16" length. Lobster claw clasp.