IGI vs GIA: Difference Between these Certification

IGI vs GIA: Difference Between these Certification

Are you curious about the contrast between IGI and GIA diamond certifications? Look no further, as I’ll be addressing the most frequently asked questions regarding these two grading organizations in this Learning Guide:

  • IGI versus GIA certification
  • Is an IGI certificate preferable for lab grown diamonds?
  • How do IGI and GIA differ?
  • Why are GIA diamonds more challenging to come by?

Differences between IGI and GIA Certification

The primary distinctions between an IGI and a GIA certification are as follows:

  • The IGI has approximately 20 global grading laboratories, whereas the GIA has fewer than 15.
  • While the IGI labs specialize in diamond grading, GIA labs are recognized as the top experts in gemstone research.
  • A diamond with an IGI certificate typically costs less than one with a GIA certificate, despite having the same grades.
  • GIA certified diamonds are generally more valuable and esteemed compared to those with an IGI certificate.

Which Diamond Certification Was Established First?

IGI Certification

The International Gemological Institute (IGI) was the first grading laboratory to provide diamond grading reports and operate 14 gemology schools. Although it is known in the diamond jewelry industry as an independent laboratory for grading diamonds, IGI also offers other services. The main headquarters of IGI is located in Antwerp.

The IGI gemological laboratories, which you will often encounter in the market, are the biggest of their kind. Established in 1975, they now operate over 20 locations across the globe, including in Dubai, Bangkok, Hong Kong, Shanghai, Italy, and New York.

GIA Certification

The Gemological Institute of America (GIA) offers a diamond grading system and certificate to determine a diamond’s quality. Additionally, the GIA serves as the world’s top resource and research center for the diamond and gemstone industry. The highest accolade one can achieve in the jewelry industry is the GIA’s Graduate Gemologist degree.

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Although the GIA has fewer campuses than the IGI lab, it has 14 locations worldwide in countries such as Taiwan, China, United Kingdom, India, and Japan. The main center is situated in Carlsbad, California in the United States. The GIA is renowned for inventing the 4Cs of diamond grading based on cut, color, clarity, and carat weight, which is the industry standard for diamond grading.

Comparing IGI Graded Diamonds to GIA Diamond Grading

Both IGI and GIA offer certification reports for natural and lab-grown diamonds, colored stones, and fancy colored diamonds. Let’s explore their similarities.

IGI Report

IGI provides lab reports for natural diamonds, lab-grown diamonds, and colored gemstones. They are the first gemological institution to offer a grading process and report for entire jewelry pieces, such as an engagement ring with a report for the entire piece.

There are various reports available to customers for each category. The most common report offered is the IGI Natural Diamond Report, which includes:

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

IGI lab reports for lab-grown diamonds contain identical information to the Natural Diamond Report. However, the laser inscription on lab-grown diamonds includes “LAB GROWN” along with the report number on the girdle.

IGI offers additional report variations for hearts and arrows diamonds and fancy colored diamonds. However, what really sets IGI apart is their Jewelry Grading Reports, although this feature has been adopted by some other labs such as GSI.

The Jewelry Report from IGI grades a piece of jewelry without having to remove it from its mount, making it an ideal choice for those who want to have a delicate heirloom engagement ring certified. The report includes a detailed description of the piece, including:

  • Number of accent diamonds
  • Description of ring setting
  • Total diamond weight
  • Type of precious metal
  • Karat gold (if applicable)
  • Other unique details of the engagement ring or jewelry piece may also be included.

GIA Report

The GIA offers different types of diamond certificates similar to IGI, but their main report is the GIA Diamond Grading Report. Unlike IGI, GIA only grades loose diamonds that weigh over .15 carats and doesn’t provide reports for jewelry pieces. GIA also offers certificates for natural and lab-created diamonds, colored stones, and pearl jewelry.

The GIA Diamond Grading Report is the standard report used for loose natural diamonds that weigh .15 carats or more. It includes:

  • Cut grade
  • Color grade
  • Clarity grade
  • Carat weight
  • Proportions of the diamond
  • Diagram of inclusions within the diamond

The Natural Diamond Origin Reports contain everything that’s in the GIA DGR, with the added features of confirming the diamond’s geographic origin and laser inscription of the report number.

The GIA Diamond Dossier Report contains the identical information to the GIA DGR, with the additional feature of laser inscription. Nonetheless, you may still ask for inscription on an engagement ring’s center stone with a standard GIA diamond report.

Moreover, the GIA now offers digital diamond reports through their latest mobile app.

Difference Between IGI vs. GIA Certification

Here’s a summary of the differences between IGI and GIA diamond certification, along with their pros and cons:

GIA Reports


  • The strictest grading standards in the industry
  • Better for resale or trade-up
  • Offers diamond origin on some certificates


  • Requires diamonds to be unmounted before grading
  • Some major jewelry chains, like Zales and Kay, overcharge for a GIA certificate

IGI Reports


  • Offers certifications for whole jewelry pieces
  • Graded diamonds are less expensive than GIA certificates with the same grades
  • Suitable for lab diamonds


  • Said to have looser grading standards than GIA
  • Not the best for resale


Buying diamonds with grading reports can be confusing, given the many gemological laboratories that provide them. If you’re choosing between GIA and IGI, here’s my recommendation:

  • For natural diamonds, go for a GIA certificate.
  • For lab diamonds, both GIA and IGI are suitable.

The reason I recommend GIA for natural diamonds is that they’re the best. GIA established the world standard for grading diamonds, and their standards are strict. Some IGI grades reportedly fall below what they would be under GIA certificates.

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

Although IGI’s reputation with natural diamonds is somewhat questionable, they were the favored report for grading laboratory diamonds. At that time, GIA also offered lab diamond reports, but they were not as comprehensive.

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However, in 2020, the GIA enhanced their lab diamond reports to include more information, leveling the playing field. Nonetheless, it’s harder to find lab diamonds certified by GIA compared to IGI.

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