IGI vs GIA for Lab-Grown Diamonds: Which Report to Choose?

If you want individual colour and clarity grades for a colourless-to-near-colourless lab-grown diamond, choose a report that records those fields. GIA’s Quality Assessment changed to Premium or Standard on 1 October 2025 for eligible stones in that service. This comparison does not cover GIA’s separate coloured lab-grown diamond reports. Check the title, date and actual fields of the report you are offered.

Buyers often call this paperwork a certificate, but GIA issues reports and assessments rather than certifying or appraising stones. Read the report before deciding how much detail it gives you, then verify its number with the issuing laboratory.

For eligible loose colourless-to-near-colourless stones of 0.15 ct or more, GIA's Laboratory-Grown Diamond Quality Assessment gives one overall tier. IGI's lab-grown diamond report can provide individual colour and clarity grades, along with polish and symmetry. Check the cut fields for the shape and report service you are comparing:

Two GIA "Standard" assessments can cover different combinations of colour and clarity. An E colour VVS2 stone and a J colour VS2 stone may both qualify if their other factors meet the requirements, so the overall tier does not tell you those individual grades. The table covers the Quality Assessment; GIA’s separate coloured lab-grown reports and older reports need to be read on their own terms.

They are quality bands for eligible stones in the current Quality Assessment service. GIA’s assessment criteria explain how the factors combine. Premium requires every relevant factor to meet the Premium criteria. Standard includes any mix of Premium and Standard factors that meets the service requirements; it is not restricted to stones that are simultaneously E-to-J and VS.

A stone submitted for the Quality Assessment that falls short of any Standard requirement receives no assessment under that service. Before submitting a stone, check the current requirements and fee schedule linked from GIA’s laboratory-grown diamond services.

Earlier GIA lab-grown reports may show individual colour and clarity grades, and the stones have not been automatically reclassified. Do not date a report from those fields alone: GIA also has current report services for coloured lab-grown diamonds. Verify the report type, issue date and record through GIA.

In its August 2025 announcement, GIA said lab-grown diamonds tend to fall within a narrow range of colour and clarity, and chose descriptive tiers for its revised D-to-Z service. The current Quality Assessment covers eligible colourless-to-near-colourless stones, while coloured lab-grown report services remain separate.

For eligible colourless-to-near-colourless stones in GIA’s current Quality Assessment, an overall tier cannot be compared one-for-one with individual grades from another report. Coloured lab-grown report services and historic reports need to be considered separately.

Ask for the actual report and compare the fields it contains, then inspect the diamond or a clear video of it. A laboratory’s name or an overall tier is not enough to establish how two stones compare.

IGI has offered lab-grown diamond grading since 2005, according to its laboratory-grown diamond report service. Its reports can provide individual colour and clarity grades for comparing stones. For the diamond you are considering, ask the seller for the actual report and verify its number with IGI.

Ask the seller for the actual report and a quote for that stone. If you plan to submit a diamond yourself, check the issuing laboratory’s current service and fee schedule. GIA reports describe technical characteristics and do not state an appraisal value.

Match the inscription, then look the report up. Both labs laser-inscribe a number on the girdle, the thin edge around the widest part of the stone, and a jeweller can show it to you under a loupe or microscope. Enter that number on IGI's report verification page or GIA’s Report Check, and make sure the shape, measurements and carat weight online match the diamond you are buying. A GIA-assessed stone should also read "Laboratory-Grown" on the girdle.

Our diamond certification guide walks through reading a report line by line, and are lab-grown diamonds GIA certified has the short answer on GIA's current service.

Does GIA still grade lab-grown diamonds?

Yes. GIA offers a Premium or Standard Quality Assessment for eligible loose colourless-to-near-colourless lab-grown diamonds of 0.15 ct or more, with no assessment when the criteria are not met. It also offers separate report services for coloured lab-grown diamonds. Check the current service requirements and report title.

Which is better, IGI or GIA, for a lab-grown engagement ring?

For a colourless-to-near-colourless lab-grown stone, an IGI report can help you compare individual colour and clarity grades. GIA’s current Quality Assessment gives eligible stones an overall Premium or Standard result. Choose the report detail you need, and check older reports and coloured lab-grown services separately.

Who has the highest quality lab-grown diamonds?

Quality belongs to the individual diamond. Read the characteristics recorded on its report and compare its cut and appearance, rather than choosing on the laboratory’s name alone.

Is an IGI certificate trusted in Australia?

An IGI report gives you documented characteristics to check. Verify its number on IGI’s official website and match the record and inscription to the stone you are buying. Keep the report with your purchase invoice.

If you are choosing a stone now, browse our lab-grown diamond engagement rings and ask for the report for the diamond you are considering.