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The IGI certificate is one of the most important document you will meet when buying diamonds, no matter natural diamond or lab-grown diamond.
IGI stands for International Gemological Institute, also known as International Gem Academy. It was founded in 1975, and it is one of the world’s largest independent gemological laboratories. Just like GIA, short for Gemological Institute of America, it is a highly recognized authoritative appraisal organization in the jewelry industry.
IGI is famous for stable grading, high reliability and continuous innovation. It is a leader and pioneer in the field of lab-grown diamond certification. You can think IGI as a neutral and professional gem quality inspection institute. They do not buy or sell diamonds at all. They only provide professional testing and grading services, then issue official reports. This report is what we call the IGI certificate.
Nowadays, IGI is the mainstream and most trusted certificate for lab-grown diamonds. Its reports are clear, detailed and easy to read. If you buy diamonds from trusted channels and check them in person, a lab-grown diamond with IGI certificate is a safe and smart investment.
Core Functions & Contents of IGI Certificate
This certificate acts like the diamond’s ID card and health check report. It records all features and quality grades of the diamond in detail. The core evaluation rules are the worldwide standard 4Cs.
- Natural Diamond: The certificate will mark this clearly.
- Laboratory-Grown Diamond: The top of the certificate will print “LABORATORY GROWN DIAMOND” obviously. It keeps all information fully transparent and avoid confusion. This is a big reason why IGI is so popular in lab-grown diamond market.
Carat Weight: The weight is accurate to two decimal places, which tells you the real size of the diamond.
Color Grade: Graded from D (colorless) to Z (light yellow or brown). The higher the grade, the whiter the diamond.
Clarity Grade: It judges the quantity and visibility of inclusions and surface marks. The grades range from FL (Flawless) to I3 (Imperfect).
Cut Grade: Mainly for round diamonds. It evaluates proportion, symmetry and polish. The grades include Excellent, Very Good, Good, Fair and Poor. A good cut decide how brilliant the diamond is.
Measurements: It shows the diameter for round diamonds, or length, width and height for fancy shaped diamonds, using millimeter as unit.
Proportions Diagram: It lists detailed data such as crown angle, pavilion angle and table percentage, for professional reference.
Clarity Characteristics Plot: It draws the type and exact position of internal and external features, very intuitive to see.
Fluorescence: It notes whether the diamond emits blue or other color light under ultraviolet light, as well as its strength.
Advantages & Discussions about IGI Certificate
Advantages
- Wide market acceptanceIGI is the most common and widely accepted certificate for lab-grown diamonds. Most lab-grown diamond brands choose IGI certification.
- Clear and transparentIt strictly separate natural diamonds from lab-grown diamonds, so customers will never get mixed up.
- Complete quality gradingIt uses the same full 4C grading system as natural diamonds, easy for customers to compare and pick.
- Global service networkIGI runs laboratories in major diamond hubs around the world, such as Antwerp, New York and Mumbai. It has great global influence.
Points to note (Common discussions)
Some insiders and buyers say IGI’s standard is a little looser than GIA, especially on color and clarity grading for lab-grown diamonds. For example, a lab-grown diamond graded VS1 by IGI may be equal to VS2 under GIA rules.
This is not dishonest. It is just a slight difference in grading scale. The most important thing is that IGI keep consistent standards within its own system. A diamond graded F color by IGI is definitely whiter than another IGI G color diamond.
GIA also issues lab-grown diamond certificates, but it mostly uses simple number grades instead of traditional letter grades. Such format is less familiar to public. On the contrary, IGI keeps the classic letter grading system, which is easier for ordinary customers to understand.
Shopping Advice for Consumers
A diamond with IGI certificate means its quality has been verified by a third-party authoritative institute. The certificate is trustworthy.
However, do not only look at the data on paper. A certificate cannot fully show the real beauty of a diamond. You must check high-definition photos or 360-degree videos by yourself. Your own eyes are the best judge. Check its sparkle, fire and visible flaws carefully.
For fancy shaped diamonds like oval and pear shape, please check if there is an ugly bow-tie effect.
Learning the small differences between IGI and GIA grading styles will help you make wiser decisions. Anyway, the IGI certificate is still a very valuable reference.
Always buy diamonds from reputable retailers. Make sure they provide complete original certificates and reasonable return policy.