IGI vs GIA Diamond Grading

When you make an investment in a gemstone like a diamond, it makes sense that you want to buy a product that you know is genuine and that is ranked as a high-value diamond. Generally, a customer will rely on their jeweler to provide this guarantee which is a standard of the diamond industry. All diamonds should have a grading report which the jeweler can use to give all the intricate details of the stone. This information has more relevance for bigger and more expensive diamonds set into a piece of jewelery or when buying individual stones. There are several certifying agencies, including the Hoge Raad voor Diamant in Antwerp, Belgium, American Gem Society, European Gemological Laboratory and the Gem Certification and Assurance Lab. However, two entities tend to have the best reputation for certifying diamonds and are most relied on. They are the IGI (International Gemological Institute) and the GIA (Gemological Institute of America). Both grade diamonds based on the 4 Cs, which are clarity, color, cut and carat weight. So, what's the difference? Use this guide to help you understand how the IGI and GIA certify diamonds so that you know the exact characteristics of your stone(s).

About the International Gemological Institute

The IGI is considered one of the most reputable diamond certifying agencies in the world. In addition to grading diamonds, the IGI also identifies other gemstones and appraises jewelry. The IGI was started in Belgium in 1975, but has locations around the world with a widely accepted method of diamond grading. The IGI uses a non-biased and consistent method to assess the value of a diamond, based on the 4 Cs. This is one factor that has contributed to the solid reputation the organization has in the diamond industry and the trust placed in IGI certificates.

About the Gemological Institute of America

Since 1931, the GIA has been considered the gold standard in diamond certification. They also deal with a variety of other precious gemstones, as well as pearls. The GIA created the Diamond Grading System, which is the industry standard for diamond grading and creating non-biased, accurate and comprehensive grading reports. GIA has several labs, which have a high reputation for consistency and accuracy. Using advanced technology and state-of-the-art equipment, coupled with a dedication to staying on top of the latest research, GIA experts adhere to strict standards that they employ with each GIA-certified diamond you find. Unsurprisingly, the GIA is most used by diamond dealers and diamond companies operating in American markets.

The Grading Labs

Both the IGI and the GIA use state-of-the-art diamond labs to assist them in the grading process. Each follows stringent guidelines and must commit to consistency. While both are considered reputable and reliable, it's also known that the GIA tends to lean toward more strict grading standards, which has led to many serious diamond buyers wanting the GIA diamond dossier report over IGI certification as the GIA is considered the foremost authority on diamonds. Keeping that in mind, there's also a certain degree of personal preference that goes into choosing which diamond grading report you want to go with your gemstone. Either institution offers services that align with the preservation of standards dealing with diamond quality within the jewelry industry.

The 4 Cs of Diamond Grading

Both the IGI and the GIA use the 4 Cs method of grading a diamond, regardless of the intended destination and use of the stone i.e. whether it's for an engagement ring or another piece of jewelry or to be sold as a single stone. This methodology for grading diamonds is globally recognized as the best way to evaluate stones, based on their quality and characteristics. Both organizations assess diamond characteristics during the certification process, providing a map that lets you know exactly what the lab experts used to grade the stones. Let's have a look at each of these 4 Cs and how they influence what you see on your diamond certificate.

Color

The color grade of a diamond can be ranked on a scale from "D" to "Z." A "D" graded diamond is colorless, and a "Z" grade referring to a stone with a light yellow or brown color. Most buyers want a colorless diamond, but with the spectrum applied, this can be found with other grades as well. The color grade of a diamond influences its appeal and value, with colorless diamonds being more expensive and valuable than those with traces of color.

Carat Weight

Carat weight refers to the weight of a diamond. A carat is equal to 200 milligrams, or 0.2 grams. While larger diamonds often carry more value than smaller stones, the value of a diamond isn't determined by size alone. Both the IGI and the GIA use carat weight as part of the determination of quality when they create a diamond report.

Clarity

Another standard of diamond grading is diamond clarity. Clarity grades are determined by the inclusions or blemishes that are present in the stone. Both the IGI and the GIA use similar standards when ranking for clarity, with flawless being the best and I3 being the grade that equates to visible blemishes. Higher clarity grades add value to the diamond as they equate to fewer imperfections.

Cut

Cut has to do with several factors, including symmetry, proportions and polish. This scale ranges from excellent to poor, obviously with a stone higher on the spectrum carrying a higher value. High-grade diamonds have a quality cut that does a better job of reflecting light, which translates to a better appearance and more sparkle when it is worn..

Grading Lab Grown Diamonds

Increasingly, major jewelry chains and individual jewelry designers/retailers are choosing lab-grown diamonds. Lab stones are much cheaper and address a number of the environmental and ethical issues that consumers are more conscious of now when making purchasing decisions. Man-made or synthetic diamonds are not diamond substitutes or simulants. They are exactly the same as natural mined diamonds in every way except their method of formation. Laboratory-grown diamonds have the same physical and optical properties as real diamonds and therefore it is acceptable that lab-grown and mined diamonds can be subject to the same grading scrutiny. The GIA began using the 4Cs method of grading diamonds in 2007, but not to the same degree as natural diamonds. In 2020, they made the switch to grading laboratory diamonds in the same way as natural stones. They now offer a full report for both lab diamonds and natural gemstones. While the GIA remains the leading gemological laboratory for grading lab grown diamonds, several others also do so, using the same standards. Lab reports are created as objective assessments for loose diamonds, both lab grown and natural versions. While the diamonds are synthetic since they are grown in a lab environment, variations in quality still happens and that means grading is necessary, so you know what you're getting.

Comparing the GIA to the IGI

Consideration	IGI	GIA
Reputation	Well regarded	Highly regarded
Grading standards	Varies, less strict	Consistent, stricter standards
Cost	Moderate	High
Turnaround time	Fairly fast	Longer
Accessibility	Widely available	Limited
Grading scale	4 Cs	4 Cs
Lab grown stones	Yes	Yes
Professional contributions	General training programs	Graduate gemologist diploma
Shapes	Fancy shapes and smaller stones	Larger stones, traditional shapes

As a consumer, you will be the end user of a diamond grading report and now you have a good overview of what to expect. The reports also give details of dimensions and the features of the cut - all the technical stuff that is relevant to the stone's physical and aesthetic appearance. When you buy individual stones or a piece of diamond jewelry at 1-800-Loose Diamonds, we are more than happy to discuss the grading certificate with you.