As far as diamond investments are concerned, if you’re going to get involved you really need to have a solid understanding of the diamond you’re buying. How can you determine if you’re spending a fair price or getting ripped off if you have no understanding of the way diamonds are graded?
You most likely know that there are a number of labs around the world that grade diamonds. But each of these different laboratories has their own system for grading these gems. So technically you can get different results and grades from two different laboratories depending on how they perform their testing.
Out of all of the existing labs today, GIA and AGS are looked upon as the top grading systems throughout the industry. Not only are they recognize as the best, but they each have their own grading system with diamond certifications to determine carat, cut, color, and clarity.
As mentioned, other laboratories do exist and EGL is one example. But as far as we’re concerned, you shouldn’t purchase a diamond unless it has an official grading from GIA or AGS. Since they are the best and most important organizations of their type, you should only be interested in purchasing diamonds that they have graded and certified.
Gemological Institute of America A.K.A. GIA
Out of the two services, the GIA also known as the Gemological Institute of America is considered the leading organization and laboratory of its type around the world. And even more important, this service is used more than any other service of its type.
This is a worldwide company that has earned great respect all across the continents, and since they were founded nearly 100 years ago in 1931, they have lots of experience under their belt. For instance, they were the Institute to come up with the International Diamond Grading System and the 4Cs. Guess what? This diamond grading system has been around for about 80 years and it will continue to stay in use for many years to come.
The headquarters of the GIA is located in Carlsbad, California but maintain facilities throughout the largest trading centers all across the world. In fact, this Institute is so large that they employ more than 1400 certified diamond graders, educators, and members of the scientific community.
The company is fully committed to delivering excellence and high quality every time, so they provide a host of educational services, perform intense research, and will continue to remain at the forefront of this industry with the latest technology being used in gemological research in this field.
American Gem Society Laboratories A.K.A. AGS
Another laboratory based in the United States is known as the American Gem Society. While fairly new when compared to GIA – they were first founded in 1996 – it’s still a renowned business nonetheless because they use a forward thinking, scientific approach as far as diamond cut grading is concerned.
As a matter of fact, this laboratory has made a number of breakthroughs determining the cut of diamonds consumer should expect. So when they were first founded by Robert M Shipley, a man who was also one of the founders of GIA, it’s surprising that they turned into the organization that they are today because they weren’t originally opened as a lab. In fact, it seems crazy that one of the founders would create another lab to rival GIA so that was obviously never the case. But the founders realized that as far as cut was concerned, there was a gap left by GIA and the AGS was designed to fill it.
Grading Diamond Color
As far as the color of diamonds is concerned, GIA has a grading scale that goes from D-Z. If a diamond is completely colorless, it receives a D grade. If a diamond has a brown or yellow hue, it receives a Z grade.
For the sake of consistency, when grading diamonds GIA will view each gemstone under specific strict lighting. They will compare each diamond to others where the color is already known to determine the color of the diamond being graded.
With a system like this, you’ll only discover slight color variations between grades D to R, and in fact it will be hardly possible to notice the differences with the naked eye. On the other hand, diamonds falling in the range of S to Z will have color deformities that can typically get picked up by the naked eye.
AGS employs this exact methodology when grading color. It even has systems in place to ensure it consistently grades using the GIA standards. The only difference is AGS has a different scale that goes from 1 to 10. A 0 to 1 is a colorless diamond on this scale, whereas a 7.5 to 10 is a diamond with a variation in color.
Grading Diamond Clarity
GIA determines diamond clarity using a scale from flawless to included. Flawless diamonds do not visibly show any inclusions or blemishes, whereas included diamonds are very obviously blemished when viewing them with the naked eye.
This scale is used worldwide and recognized throughout the world as the standard scale for clarity. AGS also uses the same clarity grading methodology, but again they’ve changed their scale from a 0 to 10 scale.
Grading Diamond Cut
GIA determines a grade for diamond cut by giving an overall assessment of the cut. And as far as cut is concerned, they are very happy with their limited system and have no intention of changing it for the time being.
On the other hand, it was AGS’s job to develop a verification system based on analysis and science and they’ve done an excellent job creating their scale.
The name of their system is called the scientific performance cut grade system. It comes in very handy using it on diamonds with a wide array of different facet arrangements and diamond shapes. By this we mean cushion cuts, Princess cuts, oval cuts, and the round brilliant cut which is very pioneering to say the least. The system takes into consideration physical measurements of the diamond and also factors in computer analysis as well.
The grade scale operates on a system of 1 through 10. The best grade possible to receive in this scale is a 1. So obviously, the worst grade is to receive a 10. This system provides very specific details about the diamond including dimensions, shape, carat, symmetry, cut, as well as profile. Human verification is no longer needed with this certification system and it removes clarity and color subjectivity altogether.
Even though GIA now offers grading based on cut, their options are still very limited at this point when compared to AGS. So if you are looking at a diamond based on the cut, make sure AGS has weighed in with their grading because they are the best at determining various diamond cut grades.
Grading Diamond Carat
As far as diamond carat assessments go, GIA and AGS both use a process very similar to one another. But there is a slight variation in the difference in processes. AGS uses a three decimal point measurement as opposed to GIA’s two decimal point measurement. The AGS measurement is actually more accurate.
It is undoubtedly true that GIA and AGS are both highly regarded laboratories as far as diamond grading and certification is concerned.
Instead of going up against each other in a nasty competition to become the most trustworthy and respected certification source, AGS and GIA are more like sister laboratories. Between the two, they have created certification processes that are comprehensive, accurate, and completely trustworthy and each laboratory complements the other.
Both laboratories employ similar yet different grading scales, and experienced diamond buyers might find this confusing. But each organization uses consistent ways to grade diamonds, so it shouldn’t be that difficult to understand.
As an example, the two laboratories have master color sets that they use to grade the color of diamonds. Each master set from AGS was graded by GIA to ensure its authenticity since GIA has set the standard on color grading. This helps maintain consistency and accuracy across all diamond color grading scales provided by both organizations.
Of the two laboratories, AGS is much smaller than GIA. But it’s still a very important lab nonetheless and they earned their established name and credibility because of their pioneering work when grading diamond cut analysis. They filled a hole left by GIA and this was done intentionally since GIA was never supposed to measure diamond cut to begin with.
Keeping all of this in mind, when it comes to purchasing diamonds you should feel confident that you can trust any grading provided by AGS or GIA. You should feel good knowing that these companies are working tirelessly to certified diamonds all over the world. But as far as cut goes, AGS is going to provide a more accurate and comprehensive certification, so also keep that in mind. As a matter of fact, the only time we would ever truly recommend GIA for cut analysis is if they supplied light performance images along with their grading, but that’s a different story for another day.