Lab grown diamond reports today. The GIA shift, and IGI as the new principal name

The world of diamond reports, the documents that vouch for quality, is moving. GIA, long the definitive authority in the natural world, has changed how it treats lab grown diamonds. What has changed, and what a buyer should confirm, taken in order.

GIA has stopped issuing full 4C reports for lab grown diamonds

In 2025, GIA, the Gemological Institute of America, announced that it would discontinue detailed 4C grading for lab grown diamonds and move to a simplified description in two tiers, Premium and Standard. GIA has chosen no longer to grade lab grown stones in fine degrees on the same scale as natural ones.

This does not mean that the quality of lab grown diamonds cannot be trusted. Lab grown quality is consistently high and the differences between fine grades are small, so GIA chose a different way of describing them.

IGI has become the principal name in lab grown diamond grading

In the grading of lab grown diamonds, IGI, the International Gemological Institute, is understood to hold more than half of the world market. Founded in Antwerp in 1975, IGI is an international laboratory with sites in many countries, and by the number of stones it grades it is among the largest anywhere. It was also among the first to take up the grading of lab grown diamonds. IGI continues to issue full grading for color, clarity, and cut, and in practice the IGI report has become the main way to confirm the quality of a lab grown stone in figures.

The worry that a stone is uncertain because it carries no GIA report does not apply here. In the lab grown world, the IGI report is the standard.

Four things worth confirming on a report

What matters more than the name of the laboratory is the content. There are four things worth confirming.

The first is the grades for color, clarity, and cut. The second is that the laser inscription on the girdle of the stone matches the report number. The third is that the growth method, CVD or HPHT, is stated. The fourth is whether a report exists at all. When a stone is priced far below the market and carries no report, there is a reason for it.

At ANNA DIAMOND, every diamond of 0.5 carat and above as a single stone comes with an IGI report. Pieces such as half eternity rings, where small stones add up to more than 0.5 carat, do not come with a report.

How to tell a diamond from the other stones that resemble it is covered at length in the article on moissanite and cubic zirconia.

Frequently asked questions

Q. Does the absence of a GIA report mean the quality is low.
No. Because GIA has moved to a policy of not carrying out detailed grading for lab grown stones, reports from IGI and others have become the standard in practice. It has nothing to do with the level of quality.

Q. Can an IGI report be trusted.
Yes. IGI holds the largest share of lab grown grading in the world and issues full grading for color, clarity, and cut. Matching the report number against the laser inscription on the stone confirms that the report belongs to the stone in front of you.

Q. Should a stone without a report be avoided.
When a stone is priced far below the market and carries no report, there is a reason for it. A stone whose quality cannot be confirmed in figures is not something we would recommend for jewelry meant to be worn for a long time.

Lab grown diamonds themselves are covered in What a lab grown diamond is, and the differences from natural stones in the article on five differences. The brilliance and the reports can be seen in person at our gallery in Daikanyama, Tokyo. No appointment is needed.