MAUI Tungsten Wedding Band with Mother of Pearl Inlay - 10mm This unique comfort-fit style from the tungsten rings collection is made of jewelry grade tungsten carbide with nickel binder, and contains no cobalt. The ring has polished beveled edges and has an inlay of beautiful mother of pearl, which has purple, blue, green, white and black colors swirling together like the waves in the ocean. Mother of pearl is a decorative material that has been used for centuries on fine furniture, musical instruments, and jewelry. It is made from the inside lining of oyster shells and abalone shells. This material is not as strong as tungsten and can possibly chip if dropped. Tungsten Carbide is the newest and strongest metal to be used in jewelry, ideal for men and women who are tired of rings that scratch easily, Free Lifetime Sizing and Lifetime Warranty on all tungsten rings, no exchange or sizing fees, which are charged by other retailers. MAUI rings are available in 4mm, 6mm, 7mm, 8mm, and 10mm.