Navajo Pearls Sterling Silver Purple Spiny Oyster 8 mm Bead Necklace Gift 366. Beautifully and artistically crafted this Necklace laced with natural Purple Spiny Oyster collectors choice. With Sterling Silver Beads and findings this beautiful necklace is a one of a kind. Spiny Oyster Beads 8 mm. Please let us know the problem before posting a bad feedback. We hope you have a great experience with us and hope for an awesome review.