Cabochon

A cabochon (/ˈkæbuʃɒn/; from Middle French caboche 'head') is a gemstone that has been shaped and polished, as opposed to faceted.

The resulting form is usually a convex (rounded) obverse with a flat reverse.

In asteriated stones such as star sapphires and chatoyant stones such as cat's eye chrysoberyl, a domed cabochon cut can show the star or eye, which would not be visible in a faceted cut.

Most lapidary workshops and production facilities have moved away from silicon carbide to diamond grinding wheels or flat lap disks.

The piece is then ground to the template line, the back edges may be bevelled, and finally the top is sanded and polished to a uniform dome.