Our line of buff top shell cabochons have a flat back and a low dome top. Commonly used in rings, cuff links, sutds, earrings or on other accessory jewelry and fashion items. As with most natural materials and lapidary hand worked items, some variation in size and color may occur. This material is a Dyed Smoke Grey MOP Base, also sometimes referred to as a Black Tahiti Pearl Color of Shell. It is color enhanced to bring out the natural highlights in the base material.