IGI Diamond Certification

IGI Diamond Certification – The Basics

You might associate the International Gemological Institute (IGI) diamond certification with lab grown diamonds, but they actually grade more diamonds, gemstones and finished jewelry than any other organization. All told, IGI operates 20 laboratories and 14 schools of gemology in diamond centers around the world.

PriceScope Pointer: A diamond grading report establishes the diamond’s all-important value-setting 4Cs. If a diamond is over graded you’ll overpay, so it’s important to choose a laboratory with a diamond grading process which follows strict, international standards.

Before going on: Check out the PriceScope Diamond Buying Guide

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IGI Diamond Certification Explained

An ‘IGI certificate’ refers to a grading report issued by one of IGI’s laboratories. This report provides all of the gemological information needed to establish a diamond’s value.

Cut Grading for Fancy Shapes

In 2022 IGI became the first worldwide laboratory to issue cut grades for fancy shapes diamonds. Most gemological laboratories only issue a cut grade for rounds. Visit www.igi.org/cut-grading for more information.

The Lab-Grown Diamond Pioneer

IGI was the first gemological institute to begin grading lab grown diamonds in 2005. That decision provided a first foothold in authenticity and standardization for a growing industry segment. Today IGI has more experience and expertise than any other organization, issuing the report of choice for Lab Grown Diamonds.

The IGI Laboratory Grown Diamond Report provides the same information as their natural diamond reports. The cover of the report is yellow to clearly differentiate the stone from natural diamonds. The girdle is also laser-inscribed with the words ‘Lab Grown,’ in tandem with the report number, for further purposes of identification.

IGI Lab Grown Diamond Sample

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ISO Accreditation for Natural and Lab Grown Diamonds

IGI was the world’s first gemological laboratory to hold ISO accreditation in both natural and lab grown diamond grading. The Organization for International Standardization 17025 laboratory competence certification is considered the single most important standard for calibration and testing laboratories across the globe.

Offered in different formats to serve consumer needs across different worldwide markets, every grading report is issued according to strict international standards, with security features to prevent duplication.

IGI Natural Diamond Sample

Jewelry Grading

IGI is the largest gemological organization to grade finished jewelry, issuing millions of reports annually. This sets them apart from the other major laboratories because consumers tend to purchase finished jewelry far more than loose gemstones. Ultimately, IGI is engaged with the grading of far more items that reach consumers’ hands than any other institute.

The grading and appraising jewelry is more complex than loose gemstone grading. After grading millions of carats of gemstones mounted in jewelry, IGI has developed techniques for providing accurate and impartial assessments of total carat weight, color, clarity, nature of origin, precious metal content and other details for finished jewelry pieces. Without disassembling heirlooms or complex pieces, IGI performs thorough, objective analysis of finished jewelry items.

IGI Jewelry Report Sample

Consumer Services

In addition to professional services, IGI offers a variety of services to consumers:

Diamond, Gemstone and Jewelry Grading

Consumers are welcome to send loose diamonds or gemstones for grading. They are also invited to send finished jewelry in for grading or full independent appraisal.

Jewelry Appraisals

IGI does not buy, sell, or trade gemstones or jewelry. This neutrality permits unbiased, accurate appraisals, appraisal-updates, and identification reports. IGI appraisers are accredited by the American Society of Appraisers (ASA) and continue their education by attending courses and conferences each year. A Jewelry Appraisal Report identifies and fully describes the gem or jewelry article, with maximum retail replacement value calculated for insurance purposes.

Diamond Screening Services

IGI screens millions of small diamonds for jewelry manufacturers, separating lab grown from natural for use in different applications. They offer this service to consumers as well, for loose or mounted diamonds. Every diamond submitted is screened using state of the art technologies to determine naturally mined, laboratory grown or simulant origin.

IGI Screening Service

Registration & Recovery Service

Consumers can register jewelry in IGI’s database in the interest of recovery if damaged, lost, or stolen. After the registration is activated, IGI’s toll-free number can be used to report loss, theft, or damage covered by insurance. If a piece is destroyed, IGI provides a printed report for the consumer’s insurance company, describing the article of jewelry in detail, with a representative photograph. If the registered item was appraised by IGI, a maximum retail replacement value for insurance purposes will be included. If lost or stolen IGI will alert jewelry industry partners equipped to provide local authorities with details about the piece. 

Is IGI the Best?

The world’s most recognized diamond grading institutes are GIA, with 11 grading locations and 8 schools of gemology, and the International Gemological Institute (IGI), with 20 grading locations and 14 schools of gemology. In the United States the Gem Certification and Assurance Lab (GCAL) are also widely recognized. 

These three institutes have much in common, but also specialize in different areas. You can get information on all of them on PriceScope’s education page covering Diamond Certification.

PriceScope’s 1-5 star ratings are categorical comparisons with the most thorough, consumer-focused online diamond and jewelry vendors, in categories, we believe reflect our experienced consumer community’s values. Check out PriceScope Jeweler Reviews

The IGI Story

IGI was established in 1975 in Antwerp, the world capital of diamonds, and is the oldest laboratory in the city today. IGI has had several notable ‘firsts.’ Their School of Gemology was the first to offer classes covering rough diamonds. The IGI Laserscribe System Mark patent introduced laser inscription to the diamond industry.

The institute was the first to issue Jewelry Identification Reports, the first lab to seal diamonds for protection purposes and the first to develop a round diamond cut grading chart.

In 2005 IGI Pioneered the grading of laboratory grown diamonds. They were the first major laboratory to issue co-branded grading reports in cooperation with jewelry brands, the first to commit to carbon neutrality and the first worldwide laboratory to develop a cut grade for fancy shapes.

Carbon Neutrality

IGI is the world’s first gemological laboratory to commit to carbon neutrality, joining the Responsible Jewelry Council, International Precious Metals Institute, and Initiative for Responsible Mining Assurance in an association with SCS Global Services for the purpose of mitigating the laboratory’s environmental impact.

eLearning Courses

IGI eLearning, launched in 2021, features short sessions which teach core gemological fundamentals while emphasizing modern information diamond, gem and jewelry buyers are most interested in. The courses are also interactive. Learners make choices along the way, verifying material is understood, resulting in 80% higher engagement than traditional online learning. Courses are “bite-sized” and manageable, typically taking less than 45 minutes to complete.  Every five-section course includes interactive questions and finishes with a quiz. Once the course is passed the user receives a summary PDF with all content. Visit www.igi.org/elearning for more information.


IGI offers more courses in more locations around the world than any other gemological organization. IGI’s Schools of Gemology offer courses in-person and online via customizable webinars and eLearning programs. From rough diamonds to computer-assisted jewelry design and retail support, IGI graduates thousands of new jewelry professionals each year.

IGI Education

IGI Appraisals

In addition to grading loose gemstones, IGI is also specialized in analyzing finished jewelry. Since 1975 their 20 laboratory locations have screened, analyzed, and graded millions of jewelry items around the world. In addition to screening and grading, IGI’s United States locations in New York and Los Angeles offer independent jewelry appraisals. Their appraisers are accredited by the American Society of Appraisers (ASA) and continue their education by attending courses and conferences each year.

IGI Appraisals have come under criticism for listing a ‘maximum’ retail replacement value. The institute takes the position that consumers should be protected with the maximum value the piece may command, so they are assured of being made whole in case of theft, damage, or loss, regardless of regionality. To that end, their appraisal reports state ‘replacement value for insurance purposes only.’ 

However, an unintended consequence of this practice is unscrupulous jewelers who work to position IGI’s ‘maximum insurance replacement value’ as if it were a ‘normal selling price,’ to make what they are charging seem more appealing to consumers, by comparison.

IGI Appraisal Report Sample

If you’re looking to buy loose diamonds online, use our special tools to reveal the best cut quality diamonds! Start your diamond search and choose from over a million loose diamonds for sale. Use our filters to find either natural or lab diamonds, as well as fancy color diamonds. 

How Does IGI Grade Diamonds?

The process of diamond grading is largely uniform among the major gemological institutes. See PriceScope’s education page Diamond Grading Explained to learn about the strict sequence of intake, analysis and reporting. 

IGI Microscope

Is IGI Better or Worse Than Others?


IGI was established in 1975 and opened offices in the USA in the late 1970’s. The Gemological Institute of America (GIA) was already well established as the country’s natural diamond grading authority. Given that GIA was responsible for the training of America’s gemologists and jewelers, most professionals did not take interest in a newly established foreign lab. Nevertheless, IGI was able to demonstrate proficiency to entities in New York City, where they were headquartered, and established a client base there. 

IGI’s practice of grading finished jewelry became their main differentiator for many years. Large national chains seeking grading from a reputable authority became IGI clients and economical ‘credit card’ sized reports issued by IGI became common coast to coast. That was the status quo for many years. In recent times, with the explosion of lab grown diamond popularity, IGI is becoming more of a household name for jewelry professionals across America, since they currently dominate the loose lab grown diamond grading market, worldwide.

‘Review’ Confusion

IGI and the European Gemological Laboratories (EGL) both opened offices in the USA in the late 1970s. Over time EGL became widely infamous for their practice of over-grading. As this happened many American jewelers made no distinction between the two organizations. They knew EGL was loose and presumed the same about IGI, without ever sampling their reports. Even today, the average independent American jeweler has never used IGI, allowing no room for correction of misinterpretations.

‘Internet review sites’ have perpetuated this cycle: IGI, GIA, AGS and EGL are all major keywords for SEO. When content creators are asked to create pages with those keywords they search for existing pages, take whatever content they find and replicate it, which only reinforces and grows misinformation and confusion.

Diamond Grading and Standard Deviation

Whether it’s IGI certification, or grading done elsewhere, due to the subjective nature of grading a standard deviation of +/- one grade is frequently deemed acceptable among professionals in the diamond grading industry.

This is perfectly logical from an analytic standpoint. At point of sale, however, a difference of +/- one grade may have significant influence on value. For this reason, it’s important for a buyer and a seller to agree on whether GIA, IGI, GCAL or another lab will issue the document of authority prior to sale.

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