A laboratory report (often called a certificate) is an independent record of a gemstone's identity and characteristics. It is the most reliable way to confirm what you are buying, especially for coloured stones and fancy colour diamonds.
What a report usually includes
- Identification. The species and variety, for example natural corundum, variety ruby, and confirmation that the stone is natural rather than laboratory-grown.
- Weight and measurements. Carat weight and dimensions in millimetres, which together help match the report to the stone.
- Shape and cutting style. Oval, cushion, pear, emerald cut and so on.
- Colour. A description of hue and, for fancy colour diamonds, a formal colour grade such as Fancy Yellow or Fancy Intense Yellow.
- Treatment. Whether there is evidence of heating in rubies and sapphires, or the degree of clarity enhancement (oil or resin) in emeralds.
- Origin. Some reports give an opinion on geographic origin, such as Sri Lanka, Burma or Zambia. Origin is an expert opinion based on the stone's internal features, and not every report includes it.
Which laboratory issued it
Reports are issued by many laboratories, and their reputations differ. Pieces in our collection carry reports from laboratories including GIA, AIGS, GRA, GFCO and GIT, and the laboratory is named on every listing. Most major laboratories let you check a report number on their website, which confirms the report is genuine and matches the details you have been given.
Report vs appraisal
A laboratory report describes the stone; it does not give a price. An appraisal estimates value, usually for insurance. They answer different questions, and a report is the better guide to what a stone actually is.
Ask to see it
Browse our jewellery with lab reports, and if you would like to see the report for any piece before you decide, contact us.