The Gemological Institute of America is the world’s foremost authority on diamonds, colored stones, and pearls.
The GIA Synthetic Diamond Grading Report offers similar data as the GIA Diamond Grading Report for natural diamonds, utilizing an increasingly broad portrayal of color and clarity. For included exposure and distinguishing proof, the synthetic diamond's girdle is laser engraved with its report number and an explanation that the stone is the laboratory-grown, and the report itself appears to be unmistakably unique from reports for natural diamonds.
The GIA is making some changes in the certification for lab created from July 1st. The first major change in the certificate is, GIA won’t use the terminology “Synthetic Diamond Grading Report”, instead it will be called “Laboratory-Grown Diamond Report”. The word “synthetic” will be removed from the “Identification” line, replaced with the “laboratory-grown.” The disposal of synthetic is with regards to late updates the Federal Trade Commission made to its Jewelry Guides, expelling the word from its rundown of suggested terms for lab-grown diamonds on account of "the probability of customer perplexity."
The report will also include the standard color, clarity, and cut scales for reference purpose only. The lab won’t use the scales it uses for natural diamonds. Like before, the lab will use: colorless, near colorless, faint, very light, and light to grade color on man-made diamonds, not D-Z. However, those terms will be listed alongside the D-Z scale so the customer can understand the color in a better way. For example, a near-colorless lab-grown diamond is the equivalent of a natural diamond that’s graded between G and J.
Similarly, for clarity, the lab will use the terms flawless, internally flawless, very very slightly included, very slightly included, slightly included and included alongside the standard clarity grade scale.
GIA has the same cut grade terms for natural and man-made diamonds which range from excellent to poor.