Cabochon

Stones usually cut as cabochons

Opaque and translucent stones such as turquoise, jade, onyx, lapis lazuli, moonstone and opal are usually cut as cabochons. Star sapphires and cat's eye chrysoberyl are cut this way too, because the dome concentrates the light that creates their star or eye.

Settings for cabochons

With no facets to grip, cabochons are most often held in a bezel or with prongs that wrap over the dome. Inlay and flush settings are common in men's rings.

Rendering cabochons

A cabochon does not need dispersion or complex refraction to look right. What sells it is the smooth highlight across the dome and the depth of colour. Use a glossy material with low roughness so the environment reflects as a soft window across the surface.

Translucent stones such as moonstone or chalcedony look best when some light passes into the stone and scatters. Opaque stones such as onyx or turquoise behave more like polished enamel. Match the material to the stone and check the colour against a real sample, because cabochons are often bought for their colour.

The environment matters a lot. A large, soft light source gives an elegant, continuous highlight, while several small lights scatter it into dots that can make a stone look like plastic.