Gemmologist

A gemmologist examines and identifies gemstones. The field is called gemmology. Work can include quality grading, investigating treatments and distinguishing natural stones from laboratory-grown stones and imitations. These questions differ from simply asking how much a piece of jewellery might sell for.

Testing beyond appearance

Examinations may use a microscope, refractometer, spectroscope and other suitable instruments. Difficult identifications can require advanced laboratory testing. GIA's education programme specifically stresses recognising when such tests are needed. A photograph or a sparkling surface alone therefore cannot establish material identity.

A diamond, for example, must be distinguished from a stone that merely resembles one. Read a report to see precisely what was examined. A grading report and a valuation serve different purposes. Gemmological training alone also does not establish specialist competence in every type of appraisal.

If you have inherited jewellery

Keep previous reports, receipts and repair information. Ask what an examination covers, what limitations the setting imposes and whether a written conclusion will be provided. Clarify whether you need material identification, a quality description or a value for a specific purpose.

For a possible sale, submit photographs through OBA's buying and selling page. If you intend to keep the jewellery and need a formal valuation, see OBA's valuation terms. Establish whether specialist testing is required before commissioning the work.