A Guide to International Gemological Institute (IGI) Certified Diamonds

The International Gemological Institute (IGI) is an organization that provides laboratory testing, identification, and evaluation of diamonds and other gemstones for the jewelry industry. It also provides education courses and degree plans for the gem and jewelry trade. IGI has taken a leading role in identification and evaluation of lab grown diamonds (laboratory created, synthetic or LG diamonds). They also have a distinction in offering evaluation and appraisal of finished jewelry items.
IGI is a large international organization consisting of 20 labs around the world, and 14 gemology schools graduating thousands of new jewelry professionals each year. Most of their laboratories are scattered through India where the majority of diamonds and colored gems are cut. With only two locations in the United States, IGI is less well known in the American market than the Gemological Institute of America (GIA) or the American Gem Society Laboratories (AGSL).
Vatche 188 Caroline Solitaire Engagement Ring for Princess
Vatche 188 Caroline Solitaire Engagement Ring for Princess

Leader in Testing Lab Grown Diamonds

IGI provides a variety of services to the jewelry trade, but perhaps none more important than screening for synthetic diamonds. While the other major laboratories such as GIA and AGS also perform this function as a first stage in their take-in process, this generally takes the form of single stone evaluations. With the recent influx of significant quantities of small man-made accent diamonds (melee) into the jewelry market, the trade had a significant problem that needed to be addressed. IGI stepped into that role and today screens millions of diamonds each year separating natural from lab grown, and issuing various kinds of reports and certificates. In addition to screening loose diamonds of all sizes, IGI is unique in offering screening services for finished jewelry.
IGI Lab Grown Diamond Certificate

ISO 9000 Certification

IGI is one of the few gem laboratories to be ISO 9000 certified (technically ISO 17025). ISO is an international system and standard of quality control and continual improvement. As Whiteflash is one of the very few retail jewelers in the world certified for ISO, we have special appreciation for this significant commitment to best practices. ISO companies can be relied upon for accuracy and consistency as a result of being required to document all nonconformities, assess root cause, and perform corrective actions. To achieve and maintain ISO certification companies must pass rigorous annual audits of their quality management system.

IGI Diamond Reports and Certificates

Like other major labs IGI issues diamond certificates on natural and lab created diamonds. As a specialist in lab diamonds, IGI reports tend to be more detailed. Their report on lab grown diamonds includes all the same information as their natural diamond reports, but the document is colored yellow to distinguish it from a natural report. The girdle of the diamond is also inscribed with the words “lab grown” at the time of grading as a protection for the consumer.
It should be noted that DeBeers and other prominent organizations in the jewelry industry are opposed to grading lab grown diamonds in the same way as natural diamonds, since the rarity factor is not relevant to the value of lab diamonds. As growing technology advances and more producers enter the market the supply and thus the value of man-made diamonds will continue to fall. Since there is no inherent rarity to a product that can be mass produced in a manufacturing facility, differences between a VVS1 and a VVS2 have no real meaning as they do for natural diamonds.
IGI also issues reports on Fancy Color Diamonds, both natural and lab grown.

Hearts and Arrows Grading

Diamond grading practices at IGI are similar to those of GIA and AGS in regards to color and clarity grading and listing of the basic dimensions and proportions of diamonds. With regard to cut grading, they do not perform light performance analysis with actual ray tracing in the way that AGS Laboratories does, but they do provide a Hearts and Arrows document on round diamonds. While hearts and arrows patterning indicates important things about the level of craftsmanship a diamond exhibits, it is not a guarantee of overall light performance. A GIA report provides little information about facet precision. And while AGS also does not provide direct reporting on facet precision, the ray tracing system will penalize light performance if facet precision is faulty. In addition, AGS platinum reports include ASET light maps which will visually show how precise the patterns are. Advanced light performance reports will show both the hearts and arrows view of the diamond.
IGI Hearts and Arrows Natural Diamond Certificate
Like GIA, IGI only offers an overall cut grade on round brilliant cut diamonds. Because, like GIA, the overall cut grade is rendered by comparing the basic proportions of the diamond to a pre-determined table of grades. The AGS light performance cut grading system is a sophisticated analysis involving ray tracing and involving every facet and measuring the outputs of brightness, contrast, fire and leakage. As such the AGS system can be applied to a wide variety of shapes and facet arrangements.


IGI is like GIA in several ways. They are a large organization with gem laboratories and gemology schools in multiple locations on several continents. IGI uses the system created by GIA for grading diamonds. The main differences are in their approach to the market. GIA offers their services to both the trade and to individual consumers. IGI submissions are made through their clients in the jewelry trade, and they tend to cater to large retailers such as chains of jewelry stores and the manufacturers who produce for those large retailers. Thus, they tend to grade a high percentage of commercial grade diamonds, in addition to some of the proprietary cuts that the large retailers promote. GIA tends to be the realm of higher end diamonds, but there is of course some overlap. GIA is the name with the highest recognition and trust factor in the market.
IGI is probably better known than even GIA for grading lab diamonds. They have been instrumental in working with the jewelry trade as volumes of labs have begun to enter the market, carving out that niche for themselves. Currently they screen millions of melee diamonds and they issue grading reports on single stones. Though both GIA and AGS screen all of the diamonds submitted to them for synthetics, IGI has developed an efficient and cost effective business model around providing this service to the diamond trade.
Like GIA, IGI has an education component, offering gemology and jewelry arts courses on 14 of their campuses. Both are dedicated to consumer education and protection. IGI tends to service the mass market, while GIA is oriented towards serving the upper end of the market.


As mentioned above IGI is a large organization with 20 locations serving the mass market. AGS laboratories is on the other end of the spectrum with all their operations currently under one roof. While AGS performs a full range of gemological services, they specialize in diamond light performance grading, having developed the most sophisticated scientific system for grading diamond cut quality. The AGS Lab caters to a wide variety of high-end retailers and manufactures including members of the American Gem Society.
Diamonds with AGS certificates tend to sell at a premium by virtue of the high cut quality of the diamonds submitted to the AGS lab. Consumers searching for Ideal Cut diamonds are naturally drawn to AGS for their state-of-the-art cut grading services. A diamond with a Triple Ideal (or Triple 0) report from AGS represents the top of the scale in the most important of the diamond 4Cs - Cut.
Like GIA, AGS tends to be preferred by those looking for high end diamonds. They are in fact sister organizations. To learn more about their similarities and differences please see our page on AGS vs GIA.

IGI Appraisals

IGI is one of the few major gem laboratories that provides appraisal valuations. This is a rather controversial issue as IGI caters to the trade but is dedicated to the consumer protection. As their paying customers are manufacturers and retailers engaged in selling the items that they submit to IGI, there is a potential conflict of interest since the trade client directly benefits from high appraisal valuations. The use of inflated appraisals as a selling tool is a major ethical problem in the jewelry trade. This practice can mislead consumers and also cause them to pay more in insurance premiums that they would with a conservative valuation.

Are IGI Certificates Reputable?

Yes. IGI is a professional organization with a talented workforce and advanced technical expertise. They have a good reputation internationally, but are not as well known in the American market. Their appraisals do raise concerns as they are used by many of their clients as selling tools, as valuations tend to be on the high end. This can be problematic for consumers as these values can often be misleading if used in a deceptive way by the seller. This issue is not confined to IGI appraisals – it is a problem throughout the industry. But most top tier laboratories do not perform this service.
In general IGI certificates are regarded as reputable and accurate. However, most consumers who are investing in a significant diamond want the extra assurance of a GIA certificate. And knowledgeable consumers looking for elite cut quality want the sophisticated light performance analysis provided only by an AGS certificate.

Training Jewelry Professionals of the Future

IGI has schools at 14 of their locations where courses in gemology and the jewelry arts are taught. They offer a wide range of coursework, including everything from rough diamond grading to gemstones, pearls, modern treatments and computer-assisted jewelry design.


IGI is a reputable grading laboratory for gemstones and jewelry. They serve the diamond and jewelry trade with 20 locations worldwide, mostly concentrated in India. They are leaders in assessing lab grown or manmade diamonds, providing screening and grading services. They provide a wide variety of services including hearts and arrows grading and appraisal valuation. They are also one of the only major labs to produce grading reports on finished jewelry.
IGI is more popular overseas than in the North American market where GIA and AGS are dominant. GIA is the most well-known gem lab in the world having created the basic grading system used by IGI and most other top laboratories. AGS has pioneered the evaluation of diamond light performance and as such an AGS report is the most sought after for diamonds of the highest cut precision, such as super ideal cut diamonds.

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