Focus on


The new Laboratory-Grown Diamond Report of the Gemological Institute of America (GIA), which is being released in electronic but not printed format.



On consecutive days, two of the world’s most influential gemological authorities have released information that indicates how gem labs are likely approach the controversial task of evaluating and reporting on the characteristics of individual laboratory-grown diamonds.

On October 13, 2020, it was the turn of the CIBJO, the World Jewelry Confederation, which distributed a Laboratory-Grown Diamond Guidance document for review by officers, members and representatives of of it affiliated national associations and representatives of commercial members. It was final stage in a more than two-year process to create a harmonised set of operating standards and principles for the laboratory-grown diamond sector.

The following day, on October 14, the Gemological Institute of America (GIA) unveiled its new Laboratory-Grown Diamond Report, which it will be releasing in electronic, but not printed format.

There are similarities in the approach taken by the two organizations. Both insist that the primary goal of the exercise is to enhance consumer confidence.

“A key principle of the Laboratory-Grown Diamond Guidance,” CIBJO noted in a statement, “is that to ensure confidence, consumers must receive complete and unambiguous information about what they are buying, so that they can make consciously informed purchasing decisions. This requires clear and accurate information that the diamonds were created industrially, and not through geological processes, as is the case with natural diamonds.”

“The evolution of GIA’s reports for laboratory-grown diamonds is fully aligned with our mission to protect all consumers,” said Susan Jacques, GIA president and CEO, in announcing the launch of the new GIA service. “Everyone who purchases gemstone jewelry — whether natural or laboratory-grown — expects and deserves the information, confidence and protection that come with a GIA report.”


The need to differentiate between natural and laboratory-grown diamonds, and more specifically to eliminate the impression that the element of rarity that is associated with many natural stones in not present with laboratory-grown goods, was a matter of emphasis for both CIBJO and GIA.

The laboratory-grown diamond sector and natural diamond sector operate according to different business models, with the relationship between colour, clarity and weight, on the one side, and rarity on the other, which exists with natural diamonds, not relevant with laboratory-grown diamonds, where colour, clarity and weight are subject to the control of the laboratory-grown diamond manufacturer,” CIBJO said in its statement. Rarity is a critical factor in setting the price of a natural diamond, and in deciding its long-term value trajectory, it added.

The CIBJO guidance suggested that the document be referred to as Laboratory-Grown Diamond Product Specification, noting that, while “the confidence of consumers will be served by their receiving an accurate and objective report of the characteristics of the laboratory-grown stone that they are buying, but, since these are unrelated to rarity, care should be taken that the report itself does not infer a similarity between a laboratory-grown diamond and a natural diamond.”

“Everyone who purchases gemstone jewelry — whether natural or laboratory-grown — expects and deserves the information, confidence and protection that come with a GIA report,” says the organization’s president, Susan Jacques.

GIA also pointedly avoids referring to its electronic document as a grading report, describing it simply as a Laboratory-Grown Diamond Report.

GIA stressed that it is committed to informing consumers and retailers about the differences between natural and laboratory-grown diamonds to ensure that consumers clearly understand the product that they are purchasing. Each LGDR report features a QR code linked to a custom landing page on GIA‘s website,, offering comprehensive, engaging and dynamic information on laboratory-grown diamonds – what they are, how they are grown and how GIA definitively identifies them.

GIA‘s clarity scale, which it plans to use for laboratory-grown diamonds, as it does for natural diamonds. CIBJO recommends that, when it comes to clarity and color, the prefix “LG” be placed before the descriptive term.


The CIBJO guidance document recommends that, if the 4Cs are used by a laboratory to describe the physical characteristics of laboratory-grown diamonds, the letters “LG” should be placed as a prefix before the 2Cs of colour and clarity.

For its part, GIA has said that color and clarity specifications for laboratory-grown diamonds will described on the same scale as its grading reports for natural diamonds, but it emphasized that that this does not correlate to nature’s continuum of rarity.

CIBJO recommended several other departures from standard natural diamond grading reports. Certain countries require that OIML/Legal Units of Measurement be used to describe the weight of laboratory-grown diamonds, it noted, and consequently its guidance document recommends that the report notes both the stone’s standard carat weight and its weight in grams.

Furthermore, noted CIBJO, since a manufactured product is involved, it recommends that Laboratory-Grown Diamond Product Specification reports include other information that is not provided on standard natural diamond grading reports. This includes the name of the manufacturer, the production batch, the country of manufacture, the method of manufacture (HPHT or CVD), and information about treatments and processes to which the stone was subject after its original manufacture.

The GIA will not include all that information, however it will note whether the method of growth was HPHT or CVD,  and whether it may include post-growth treatments that were used to change the color.

All laboratory-grown diamonds submitted to GIA will be laser-inscribed with the GIA report number and the words “LABORATORY-GROWN” to ensure that consumers can clearly differentiate them from natural diamonds. Any stone submitted that is already inscribed with laboratory-grown, laboratory-created, man-made, synthetic or [manufacturer name]-created will only receive the report number inscription.