Cabochons

A cabochon or cabachon is a gemstone which has been shaped and polished as opposed to facetted. The usual shape for cutting cabochons is an oval. This is because the eye is less sensitive to small asymmetricalities in an oval (as opposed to a round shape), and because the oval shape, combined with the dome, is attractive.

Cutting "en cabochon" is usually applied to opaque gems, while facetting is usually applied to transparent stones. Hardness is also taken into account as softer Gemstones with a hardness lower than 7 on the Mohs hardness scale are easily scratched, mainly by silicon dioxide in dust and grit. This would quickly make translucent gems unattractive. Instead they are polished as cabochons, making the scratches less evident.