IGI vs GIA Certification: Which One Should You Choose?

When buying a diamond, the first step is to find a trustworthy jeweler, but if you are making a substantial purchase, it is even more important to ensure that the diamond comes with a grading report from an accredited laboratory.
No other way exists to ensure a diamond's quality is commensurate with its price, or that it will be what the seller claims. With the emerging demand for lab-grown diamonds, GIA, IGI and other labs not only screen them but also provide grading reports on them. Thus, consumers can compare their diamonds qualitatively to others on the market.
Valoria French-Set Diamond Engagement Ring
Valoria French-Set Diamond Engagement Ring
Two of the most common acronyms you might see next to a diamond are The International Gemological Institute (IGI) or the Gemological Institute of America (GIA). The IGI and GIA both certify diamonds through a comprehensive grading process, which involves evaluating the diamond's characteristics and documenting the findings in a detailed, accessible report.
But when it comes to IGI vs GIA Diamond certifications, which is the right choice? Despite the differences between them and their function in the market, the bottom line is that both labs have established reputations for evaluating diamonds. Here's an in-depth look at the nuances of both, so you'll be informed for your next purchase.
Before we start: An official attestation for a diamond is referred to as a "certificate.". However, this is not what most laboratories provide. "Grading reports" are produced with fine print stating that grades are opinions. This is the nature of the process as some aspects of diamond grading are the product of trained human graders making calls that are often borderline between one grade and another.
The lab's certificate may be incorrectly interpreted by some as an endorsement instead of a description of the diamond.
Although diamond certificates are not always referred to as grading reports by people in the trade, many still refer to them as such. Exceptions are made by the GCAL, which issues guaranteed certifications. We strongly recommend that you do not buy any significant diamond without a Grading Report.

What are IGI Diamond Certifications?

Founded in 1975, The International Gemological Institute (IGI) has grown into a globally recognized organization with a significant presence in the diamond and jewelry industry.
As part of their service to the jewelry industry, the IGI conducts laboratory testing, identification, and evaluation of diamonds and other gemstones. In addition, it offers education courses and degree plans for the gem and jewelry industry.
With a network of 20 laboratories strategically located around the world, IGI maintains a robust and widespread presence. While many of these labs are situated in India, a hub for diamond cutting and processing, IGI's global reach extends to key diamond trading and jewelry markets, enhancing its ability to serve the international gem and jewelry community.
A major role has been played by IGI in identifying and evaluating lab grown diamonds. Their specialty is also evaluating and appraising finished jewelry pieces.
IGI Grading Reports
The diamond grading process at IGI is similar to that of other major labs such as GIA and GCAL in regard to color and clarity grading and reporting the basic dimensions and proportions of diamonds. In this way, consumers can confidently evaluate diamonds based on color, clarity, and other essential criteria, and make meaningful comparisons. The report also enables accurate identification of the diamond distinguishing it from any other diamond, in the event of mix-up or recovery of stolen property.
In addition to its role in diamond certification, IGI specializes in evaluating and appraising finished jewelry pieces. These appraisals offer valuable insights into the quality, materials, and craftsmanship of jewelry items, enabling consumers and stakeholders to make informed decisions regarding their investments.

What are GIA Diamond Certifications?

In 1953, GIA's first laboratory opened and diamond grading reports were created. This grading system is still in use over seventy years later, and is the basis of all grading done by laboratories worldwide.
With few exceptions, the 4 C’s are still evaluated in the same way globally. In most labs, color and clarity grades are standardized. There may be some variations between labs in some aspects of grading.
Diamond Colors from D to K
Diamond Color as seen from the side (click image to enlarge)
No other organization has had as much influence on the modern world of gemstones and fine jewelry as the GIA. The GIA diamond report is based on the same evaluation that GIA has been performing for decades. It involves:
Additionally, larger stones will have a stone plot that describes the internal and external characteristics, at least those necessary to identify the stone and support its clarity grade. GIA also tends to be preferred by those looking for high end diamonds.
GIA Certification
Click to enlarge
GIA pioneered diamond grading tools from its earliest days, and taught jewelers how to use them in their education curriculum. A division of GIA, Gem Instruments, has brought dozens of devices to market to help identify natural gemstones, lab-grown diamonds and separate fakes. Those tools include the refractometer, polariscope, and dichroscope.
In recent years GIA has developed sophisticated devices to separate natural from lab-grown diamonds.
The Gemological Institute of America has also recently combined forces with the American Gem Society (AGS) in the area of diamond cut research and development.
As of now, GIA customers can order an AGS Ideal addendum report for diamonds that qualify for the AGS Light Performance grade of Ideal. In this way, the existing Excellent grade for rounds can be segmented by recognizing diamonds that are both GIA Ex cut and also achieve the higher AGS Ideal standard.
Additionally, it will now enable GIA to issue cut grade reports on fancy shapes.

IGI vs GIA Diamond Certifications: How Do They Differ?

Both organizations follow rigorous protocols to ensure accurate and reliable diamond certifications, but they both have different strengths in the market. We’ve detailed some differences below.

Reputation and Recognition:

GIA: The Gemological Institute of America is widely regarded as one of the most prestigious and internationally recognized diamond grading laboratories. It has been operating for several decades and is highly respected in the industry.
IGI: The International Gemological Institute is a global organization with a talented workforce of diamond and gemstone professions offering advanced technical expertise.
IGI 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. IGI has developed an efficient and cost effective business model around providing this service to the diamond trade.


There can be a significant difference in the price of a diamond based on whether it has been graded by the GIA or IGI. Diamonds with GIA reports tend to command the highest prices, at least for natural diamonds.
A Diamond Grading Report itself does not include value or price. Grading reports reflect only quality, not pricing. Market prices may change after the report is published, but the report is meant to remain valid by detailing the relevant quality factors.
An independent appraisal is the most reliable way to certify the value at the time of purchase for insurance purposes.


GIA: The GIA employs an extensive team of PhDs, scientists, and researchers to study a wide range of gemology topics. In addition to developing new instruments, this research determines how to detect and identify lab-grown and new enhancement treatments.
As a result of data from thousands of specimens studied over the years, new services like Origin Reports have been developed.
IGI: 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. We have special appreciation for this commitment to best practices as Whiteflash is one of the very few retail jewelers in the world to be certified under ISO.
IGI reports often contain additional information about quality factors that GIA reports omit, such as diamond type and optical symmetry (hearts and arrows). On lab diamonds IGI also reports growth method (CVD vs HPHT) which GIA reports do not disclose.
Besides screening loose diamonds of all sizes, IGI also offers jewelry screening services.

IGI vs GIA diamonds: Which Should You Choose?

Since the GIA is the premier grading organization, buyers often limit their search to diamonds with its stamp of approval. It is important to note, however, that both the GIA and IGI offer diamond grading services that are of high quality.
When you buy a diamond, you need assurance that the price is based on an accurate assessment. The two organizations provide easy-to-understand analyses of diamond characteristics in order to address that problem. Having earned a reputation for reliability, they provide excellent results both for natural diamonds and lab-grown diamonds.
IGI and GIA are similar in several ways. They are both large organizations with gem laboratories and gemology schools in multiple locations on several continents. IGI even uses the system created by GIA for grading diamonds.
The main differences are in their approach to the market. GIA offers its services to both trade and individual consumer markets.
IGI submissions are made through their clients in the jewelry trade, and they cater to large retailers such as chain jewelry stores and manufacturers who produce for them. Due to this, they usually grade a high percentage of commercial-grade diamonds, as well as some proprietary cuts that are promoted by large retailers.
GIA is better known in the American market, but IGI's sheer number of reports for laboratory-grown diamonds may eventually improve its reputation in the US for its natural diamond grading and full palette of gemological services. With the acquisition of AGSL by GIA, we have seen that the gem laboratory community is undergoing significant changes.
It is true that GIA tends to specialize in high-end diamonds, however, there is some overlap. As the most trusted name in the market, GIA has the highest recognition factor.
In order to make an informed decision regarding a diamond purchase, you need to consider your specific needs, your budget, and the characteristics of the diamond that are most important to you.

Not Sure Which Diamond Certification is Right for You?

At Whiteflash, we strive to stay ahead of the diamond industry as it evolves, develops, and innovates. We know not everyone has the expertise we have cultivated over the years with our team and passion, so as a buyer, we encourage you to carry out your due diligence.
You can take a look at our comprehensive diamond education resources on our website, or contact us directly for expert advice at your fingertips. We’d be happy to help discuss the best certifications for what you desire.

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