A gemstone shaped and polished to a smooth, rounded surface rather than cut with flat facets.
The CNRTL’s TLFi defines the cabochon, in jewelry, as a precious or semi-precious stone that is polished but not faceted, convex in form; the word derives from caboche, a familiar French word for head. CAMEO, the materials database of the Museum of Fine Arts, Boston, describes a highly polished, rounded surface, and lists gems typically cut en cabochon, among them lapis lazuli, turquoise, opal and moonstone, and star or cat’s-eye sapphire and chrysoberyl.
The dome is what shows a star or a cat’s eye. GIA explains that asterism, a six-rayed star formed by crossing bands of reflected light, occurs in the dome of a cabochon, as in rubies and sapphires. Chatoyancy, the cat’s-eye effect, is a band of light reflected from many parallel, needle-like inclusions inside a cabochon, seen in cat’s-eye chrysoberyl and tourmaline. Outside jewelry, the TLFi also gives the word for a nail with a decorated head, used in furnishing, upholstery and sewing.
In job listings
Cabochon is seldom named in listings. It is working vocabulary for the people who handle colored stones: the stone setters who mount them, the gemology and colored-stone quality control roles that assess them, and the advisors who present finished jewelry. See current stone setter roles.
