AGS Diamond Certification Explained

Diamond purchasing is a serious business. Whether you are a diamond jewellery buyer, or someone who is in the market for a top diamond gemstone as a jewel or as a collector knowing the quality of your stones is a key point that cannot be missed.

When it comes to purchasing top-quality diamonds: gemstones that meet the standards in terms of gem quality, authenticity and value, it is vital that the gemstones that you purchase are certified by a diamond authority. And in the diamond and diamond jewellery world, there are a few diamond certifying authorities around, and the question is: which one should you pick?

In this Education page, we will be looking at the American Gem Society or AGS. A renowned player in the diamond certification business and among the oldest in the industry.

A Short History of AGS Diamonds

Diamond certification is an important factor in the diamond trade and it is no surprise that the certification of diamonds took around the time the diamond industry: trades in carbon-based stones and jewellery start to take off as the first decades of the 20th century roiled by. Founded in 1934, AGS is one of the oldest diamond certification companies in the world.

An organisation that is also among the most respected, as it grew out of the need to protect customers from misinformation and sensational adverting that revolved around the marketing and sale of diamonds. The commitment to diamond quality matched by a rigorous assessment of the specific factors that contribute to diamond quality has made AGS a household name.

The AGS entered the popular imagination more strongly, being one of the first leading diamond authorities to integrate a computerised gemstone grading method, in 1996. This is important, as some have confused this date with the inception of AGS which is not true. AGS diamond certification pride itself on the top quality certification they provide, particularly when it comes to diamond cuts: the most important factor in diamond quality.

Why Diamond Certification is Important?

Before we proceed to analyse the strengths of AGS and how it differs from other notable diamond certifying authorities in the business, it is important to have a quick look at the process of diamond certification and its significance.

The diamond industry features a number of players: from the diamond mining companies, diamond cutters, diamond jewellers (which may or not involve diamond cutting), and the various traders who are involved in selling diamonds to other companies (B2B), and then there are the customers. In this mix, it is important that some authority holds the middle ground and ensure quality control of the diamonds that are bought and sold.

This is the function of the diamond certifying authority. And it is a complex process involving a certain kind of expertise that others in the space cannot duplicate or at least carry out with the same degree of credence. 

So to carry out the process of diamond certification the diamond authority uses dedicated labs, with tools, and measurements, many of them now computerised; to asses, calibrate and measure the specific quality of each stone. Whilst the specific techniques of measurement and quality control will vary from authority to authority, they are bound by rules of independence and impartiality.

How AGS Grades Diamonds?

AGS, like all other top diamond certification authorities, determine the quality of the stone by looking at its value on the basis of its colour, clarity, cut and carat. At this point, the reader is likely to think of the GIA and its famous 4Cs. Understandable. But the AGS differs in certain key ways. Let’s look at each one:

• Cut: The most important diamond quality factor is measured by the AGS according to a 0 – 10 scale. With a 10 being reserved for ‘Poor’ quality cut. With diamond cuts in the 8 above number being on the lower end.

• Clarity: With diamond clarity, we are once again faced with the same 0 – 10 measure. What is interesting about AGS is that since it adopts a number scale, it provides a more specific grading of the diamond clarity. However, at the same it also combines clarity levels. For example in contrast to the GIA clarity measure, AGS combines internally flawless and flawless diamonds (the highest clarity grades) under 0.

• Colour: With diamond colour the 0 – 10 scale adopted by AGS means there is a smaller range of diamond colours that are measured for quality in contrast to the wider D – Z of GIA. However, this simplifies the process of selecting diamonds for colour slightly, as diamonds which only in the 0 – 5 mark are top gem quality stones.

• Carat: When it comes to the measurement of a diamond carat, the principle is broadly the same: with diamond weight being considered. However, the AGS grade is supposed to be more precise with gemstones weighed in relation to the third decimal place instead of the second with GIA.

AGS vs GIA Diamond Certification

This is arguably the most important question in the mind of readers. And it is a tough one to answer. The first point to consider is that some persons have their choice of favoured diamond certifying authority. A decision comes down to a number of factors: history, location and clarity of the grading report.

In the diamond world, the GIA leads the way with its 4Cs of diamonds and its broad adoption in the diamond gemstone and jewellery world. However, AGS has been making its mark as well. Notably with its precision grading of diamonds, the use of modern technology, and notably its global presence. Whilst not as expansive as GIA is a considerable one.

A notable difference between the AGS and GIA grading methods is the addition of another separate grading factor: Diamond proportions. Which is an added element of measure so to speak with AGS diamond grading. One that measures the stone’s symmetry and proportions. Whilst this measure falls under the Cut grade for the GIA, the AGS provides specific attention.

Another key point is that AGS provides multiple diamond reports. In addition to the standard diamond grading report, it also puts out a Gold Diamond report. One that is reserved for round brilliant cut diamonds.

Interestingly, when it comes to comparisons between the two major diamond authorities, the GIA and AGS work together in certain areas. Such as AGS employing experts trained by GIA and sharing measurement sets in diamond colour. and So to answer the question: which is better? The answer is we cannot say, but the diamond quality factors need to consider in relation to the measurements.

Is AGS the Better Choice for Diamond Certification

As noted, one of the interesting aspects of AGS diamond reports is its multifaceted character. In addition to the standard AGS diamond report which provides a detailed breakdown of the key features of diamond quality, the AGS also provides a more simplified AGS Gold Diamond report. That in addition, possibly as a sign of its trust in its abilities, also includes GIA grading as well.

Arguably what sets the AGS diamond grading system apart from the rest is its distinct system, which is its top Platinum Quality Diamond Report. One that is built on its distinct diamond grading technology which uses sophisticated light performance measure, with 3D imaging technologies, that is able to measure diamond quality. Which is supposed to make diamonds that are graded for cut by AGS the best in the business.

In addition, AGS is also known to grade diamond cut grades for cuts other than the popular round brilliant cut. As the tools and methods employed by AGS is able to manage which GIA apparently cannot. And there is some speculation that AGS top graded diamonds for Cut, are superior to weaker Excellent Cuts in GIA range. At the end of the day, the customer has to decide what is best for him, with the knowledge available. Which is what we are here to provide.