IGI vs GIA Certification — What is the Difference?

Last Updated on October 18, 2023 by Juli "Jewels" Church

Wondering about the difference between IGI diamond certification and GIA diamond certs?

You're in the right place. In this Learning Guide, I'll answer the top questions asked about these two grading authorities: 

IGI vs GIA certification
  • Is an IGI certificate better for lab grown diamonds?
  • What’s the difference between IGI and GIA?
  • Why are GIA diamonds harder to find?

Main Differences between an IGI vs a GIA Certification

  • The IGI grading lab has around 20 locations in the world, whereas the GIA has less than 15.
  • IGI grading labs are geared towards grading diamonds, whereas GIA grading labs are renowned as the leading authority in gemstone research.
  • An IGI certified diamond will cost less money, whereas a GIA certified diamond of the same grades would cost more.
  • An IGI certificate isn't valued much, whereas diamonds with a GIA certificate are considered more valuable.

Which Diamond Certification Came First?

IGI Certification

The International Gemological Institute (IGI) grading laboratory provides both diamond grading reports as well owns 14 schools of gemology. However, most customers in the diamond jewelry industry know it as an independent laboratory that will grade diamonds. IGI Antwerp is the main headquarters.

It is the largest of the diamond laboratories that you'll frequently see on the market. The IGI gemological laboratories were founded in 1975. Today, they have over 20 locations worldwide in places like

  • Dubai
  • Bangkok
  • Hong Kong
  • Shanghai
  • Italy
  • New York
  • GIA Certification

    The Gemological Institute of America (GIA) also provides a grading system to determine a diamond's quality in the form of a diamond certificate. In addition, the GIA is the world's leading resource and research hub for all things in the gemstone and diamond trade and research. The GIA's Graduate Gemologist degree is the highest honor one can receive in the jewelry industry.

    The GIA doesn't have as many campuses as the IGI lab, but has 14 locations around the world in places like:

    • Taiwan
    • China
    • United Kingdom
    • India
    • Japan

    The main hub is located in Carlsbad, California in the United States. The GIA is most famous for creating the 4cs of diamonds. It is the gold standard for grading diamonds by cut, color, clarity, and carat weight.

    IGI Graded Diamonds vs GIA Diamond Grading

    Both the IGI diamond certification and GIA diamond certification give reports with their diamonds, colored stones, or fancy colored diamonds. Let's compare the similarities between the two grading authorities.

    IGI Report

    The IGI provides lab reports for natural diamonds, lab grown diamonds and colored gemstones. They are also the first gemological institution to offer a grading process and report for whole jewelry pieces. An example of this would be a whole engagement ring having a report rather just the individual diamond in the center.

    There are a few different reports available to customers under each category. The most popular report offered is the IGI Natural Diamond ReportOn this report, you will find

    • 4Cs assessment: cut, clarity, carat, and color grade
    • Diamond shape
    • Measurements and proportions
    • Clarity characteristic plotting graph
    • Laser inscription with report number

    The lab created diamonds reports from the IGI contain the same information as the Natural Diamond Report. However, the laser inscription on lab created diamonds indicates "LAB GROWN" on the girdle in addition to the report number.

    IGI provides additional variations of their reports for hearts and arrow diamonds and fancy colored diamonds. The Jewelry Grading Reports from the IGI is what really sets them apart from the rest of the pact, or it did for some time. Other labs like the GSI can provide a cert for an entire engagement ring.

    The Jewelry Report from the IGI grades a piece of jewelry without ever needing to unmount it. This is especially helpful for those who might want a delicate heirloom engagement ring with a report. The Jewelry Report contains a thorough description of the piece that may include:

    • How many accent diamonds
    • Description of ring setting
    • Total diamond weight
    • Type of precious metal
    • What karat gold (If applicable)
    • They may contain other details unique to the engagement ring or jewelry piece.
    igi jewelry report

    GIA Report

    Like IGI diamonds, GIA diamonds can have multiple variations of diamond certificates. The main report is the GIA Diamond Grading Report. Unlike the IGI, the GIA will only grade diamonds that are loose and weigh more than .15 carats. They don't grade jewelry pieces as a whole. There are GIA certificates for natural and lab created diamonds as well as colored stones and pearl jewelry certificates.

    The standard diamond grading report is the GIA Diamond Grading Report. It is only used for a natural loose diamond graded at .15 carats or more. This report includes:

    • Diamond cut grade
    • Diamond color grade
    • Diamond clarity grade
    • Diamond weight
    • Graphic of Diamond proportions
    • Plotted diagram
    gia cert report

    The Natural Diamond Origin Reports includes the same as the GIA DGR in addition to:

    • Confirmation of geographical origin
    • Laser inscription of report number

    The GIA Diamond Dossier Report includes all the same information as the GIA DGR, but also includes laser inscription. However, you can request inscription on an engagement ring center stone with a standard GIA diamond report.

    The GIA also provides digital diamond reports via their new mobile app.

    IGI vs GIA Diamond Certification Summary

    You know the information that both of these diamond grading authorities offer on their grading reports. Now lets see how the measure up from pros and cons standpoint.

    GIA Reports 


    • Most in the industry agree that GIA has the top strict grading standards
    • GIA certifications are better for resale or trade-up
    • Offers diamond origin on some


    • Requires all diamonds to be unmounted before grading
    • Major jewelry chains like Kays or Zales overcharge for a GIA cert

    IGI Reports


    • Offers certs for whole jewelry pieces
    • IGI graded diamonds are less expensive than GIA certs for a stone with the same diamond grades.


    • IGI certified diamonds are said to have looser grading standards
    • IGI certified diamonds aren't best for resale


    It can be a little confusing when trying to buy diamonds with grading reports. There are many gemological laboratories that provide grading reports for both natural and lab diamonds.

    If you've narrowed down your choices between GIA diamonds and IGI diamonds, let me give you my expert recommendation.

    If you are buying a natural diamond, go for a GIA certified diamond.

    If you are buying a lab diamond, both GIA and IGI are suitable laboratories.

    The reason why I opt for a GIA diamond over the IGI is simply because they're the best. The GIA is the leader in everything gemology. They established the world standard for grading diamonds. They have strict standards for grading.

    When compared to a IGI diamond of the same grade, it has been said that some IGI report grades fall below what they would under GIA certificates.

    Furthermore, IGI diamonds used to be the go-to report for retailers. They have been replaced in that fashion by GSI certificates. They were originally intended to help the retailer, not the consumer.

    While their reputation with natural diamonds is little spotty, the IGI was the preferred report for grading laboratory diamonds. At the time, the GIA provided lab diamond reports, but they were not as extensive. In 2020, the GIA revamped their lab diamond reports to expand their information and even the playing field. However, GIA certified lab diamonds are harder to locate than IGI ones.

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