Details: Trilobite: smaller size approx. 24mm x 16mm. Larger size approx. 30mm x 20mm. When placing your order, please specify which size ring you would prefer. Adjustable 5-7mm ring shank. Fits ring sizes: 5-10. Due to the one-of-a-kind nature of the fossil, the color and shape pattern may vary slightly from the image shown. Handcrafted in .950 sterling silver by artisans in Mexico. All charles albert pieces are signed/hallmarked.