Fossilized mammoth, tsavorite and pearl ring Bibi van der Velden, Bibi van der Velden's statement ring is crafted from fossilized mammoth ivory to resemble a toad. The hand-carved creature clasps a pearl between its webbed feet and is decorated with 18-karat gold and 0.026-carats of tsavorites Size: 7. Gender: Female. Age Group: Adult.