Are lab-grown diamonds GIA certified?

The current Quality Assessment is for eligible loose colourless-to-near-colourless lab-grown diamonds of 0.15 ct or more. Premium requires D colour, VVS or better clarity, excellent polish and symmetry, and an excellent cut grade for round brilliants. Every relevant factor must meet the Premium criteria.

Standard can combine Premium-level factors with Standard-level factors. A stone need not be E-to-J colour and VS clarity simultaneously; for example, D colour with VS clarity may qualify as Standard if the other requirements are met. The Standard minimums are VS clarity, E to J colour, very good polish, very good symmetry (or good for fancy shapes) and very good cut for round brilliants. A stone that fails any minimum receives no Quality Assessment. An assessed stone is laser-inscribed "Laboratory-Grown" and its GIA quality assessment number.

Read GIA’s Quality Assessment criteria and submission requirements

Older GIA reports can retain individual colour and clarity grades; their stones have not been automatically reclassified. Those fields alone do not prove a report is old, because current coloured lab-grown services are separate. Verify the report title, issue date and GIA record.

GIA lists a Laboratory-Grown Colored Diamond Report and a separate Color Identification service alongside its colourless-to-near-colourless Quality Assessment. Check which service produced the report before comparing it with another stone.

Check GIA’s current laboratory-grown diamond services

An IGI report can provide individual colour and clarity grades, while the current GIA Quality Assessment gives an overall tier for eligible colourless-to-near-colourless stones. Read the actual report fields, including any cut information, and compare the appearance of the stone itself. Match the girdle inscription to the report number and verify the record with the issuing laboratory.

Buyers often use "GIA certified" when they mean a stone accompanied by GIA paperwork. GIA says it does not certify or appraise gemstones; its reports record technical characteristics under the relevant service.

Read GIA’s explanation of reports, certification and appraisal