Glossary term
Treatment
Any human process, beyond cutting and polishing, that alters a gemstone’s appearance.
A treatment (or enhancement) is any process other than cutting and polishing that changes a gemstone’s colour, clarity or durability, for example heating, diffusion, irradiation, fracture filling or oiling. International trade standards require treatments to be disclosed at every sale. Treated stones are typically worth less than comparable untreated stones.