Spiny Oyster Shell EarringsSensational Spiny Oyster Shell Post Earrings! These lovely earrings are stamped sterling silver. They are handcrafted by Native American artist, E. Richards. Spiny Oyster shell is a difficult shell to harvest, that is most common in traditional Native American jewelry design. It is a rarity to come across beauties like these! Spiny Oyster Shell Stamped . 925, Sterling Silver Earrings are 2 in length Handcrafted by Native American Artist, E. Richards.