Lab-Grown Diamond Grading

International Gemological Institute (IGI)

The International Gemological Institute (IGI), based in Antwerp, Belgium, was established in 1975, and is the largest independent gem certification institute in the world. After GIA, they are the 2nd most recognized lab in the world. While the IGI is more widely known outside the US, particularly in Europe and Asia, they operate offices locally within Los Angeles and New York.

IGI was the first laboratory to provide a comprehensive lab-grown diamond grade that included all 4 C’s. The IGI Laboratory Grown Report provides identical information to the IGI Diamond Report, however, the color of the report is yellow to help distinguish between lab-grown and earth-mined reports. In addition, the IGI laser inscribes each lab-grown diamond girdle with the report number as well as the words "lab grown.”

View an example grading certificate.

Gem Certification & Assurance Lab (GCAL)

Gem Certification & Assurance Lab (GCAL) is an independent laboratory providing expert authentication and quality grading certificates for diamonds. GCAL was established in 2001 with the goal of providing an independent, honest and fair assessment of the quality of diamonds and is the only diamond lab in the world to earn the prestigious ISO 17025 Forensic Accreditation that assures customers they are grading consistently and accurately. GCAL offers an exclusive “zero-tolerance” 4Cs Consumer Diamond Grading guarantee, and Gemprint® (an optical fingerprint) for each lab-grown diamond.

View and example GCAL grading certificate.

Diamond Foundry

Diamond Foundry issues a certificate for loose diamonds which is a full warranty that guarantees the laboratory-grown diamonds quality. The certificate ID is laser inscribed on the girdle of the diamond and every loose lab-grown diamond larger than 0.85 carats will come either with a full GCAL or Diamond Foundry certificate.

Diamond Foundry certifications are based on a GIA gemologist verifying the analysis of an internationally recognized independent gemological laboratory, GCAL, based in New York. In the event that a loose diamond turns out to not meet a characteristic promised in the certificate, Diamond Foundry will promptly accept the return of the diamond and provide you with a refund of the full purchase price, or replace the diamond with a diamond that meets or exceeds each of the characteristics warranted.