Last updateWed, 01 Apr 2020 1pm

The Retailer’s Perspective: Gemology 102 (since I’ve already written one called Gemology 101)

At a conference recently, I was reminded that not everyone that reads my column has been in this business for several decades. And, they might just be reading me to learn something. Yikes! The pressure. Well, alrighty then, let’s learn something today.

There’s a lot of buzz lately about diamond certifications that have no basis in reality.  So, what is reality?  Well I’m gonna tell you my version of it. Let’s start with where all of those VS2s and VVS1s with H-color or I-color came from. 

Way back in the 1920s, a man named Robert Shipley realized that there was no standard when it came to diamonds and gemstones. He took it upon himself to learn as much as he could and then teach it to others. It was during this time that he developed ‘The 4 Cs’. Ten years later, the first Gemological Institute of America was established in Los Angeles. Then, in 1953, the ‘GIA Grading System’ became the international standard for determining diamond quality. Now don’t get me trying to explain how something becomes the ‘international standard,’ but by golly it did. And it remained that way all the way up until the internet got invented by Al Gore in the ‘90s. But what does it mean and why is it important?

First, let’s understand a diamond crystal. Most experts agree that diamonds were formed about 63 million years ago, way down deep in the center of the planet. A diamond is a single ingredient gemstone - carbon.  Nothing more, nothing less. On the periodic chart of elements it’s the ‘C’.  It forms in the cubic crystal system and has a hardness of 10 on the Mohs scale of hardness.

But, here’s a little tidbit for you. The difference in hardness on the Mohs scale from 1 through 9 is equally spaced; meaning that the difference between 2 and 3 is about the same as the difference between 7 and 8. But, after nine, if you kept the spacing accurate there would be nothing until 144. Then there would be diamond.  That’s how hard those little rocks are.

But, on the toughness scale, which measures a gemstone’s propensity to not break, it’s not a 10. It’s so hard it’s a lot lower on the toughness scale and they can be broken. And you want to know something? When a diamond breaks, it makes a sound unlike any other sound on the planet. I can’t describe it, but I’ve damned sure heard it a few times in my life. It’s the sound of heartbreak for sure. But I digress…

When the GIA scale was invented, the decision was made to not start the color scale at ‘A’ for a couple of reasons. If it started at ‘A’, then every single diamond sold would have an ‘A’ grade, or ‘AA’, or ‘AAA’.  So to separate the men from the boys, so to speak, they decided to start the scale at ‘D’ for diamond. That way, if someone was telling you it had an A or B color you would know immediately that you and they were not on the same page - kind of like some of those overseas diamond certifications we’re seeing lately.

So, what gives a diamond its color? Honestly, I don’t remember because it really doesn’t matter when you’re selling a diamond. Remember, the crystallization process began 63 million years ago and lots of different trace elements could have been introduced over the years altering the color of the host crystal. But what’s really important here is not to understand why it’s a certain color, but to understand what color it really is.  ‘D’ is a completely colorless diamond and considered the most desirable. But, for the most part, every diamond between ‘D’ and ‘I’ show very little color to the untrained human eye. Once you get to ‘J’ and above you start seeing noticeable yellow or brown.

When the GIA scale became the standard, a bunch of really smart people put a bunch of diamonds together and sorted them by color and everyone agreed on what the colors were. Then they developed a set of Master Diamonds that jewelry stores could buy and use to compare and assign proper color grades to their diamonds - and it was a HUGE investment. Nowadays most people, like me, have a CZ master set for comparison purposes. So when it comes to color, what’s most important is that everyone agrees that the color you are assigning the diamond is based on the GIA color scale and not something you’re just pulling out of your butt.

So now let’s move on to the Vs, the Ss, and the Is of the scale. For the most part, any trained gemologist is going to make up their mind about the grade of a diamond in just a few seconds. But, if you’re going to have to express that opinion to someone either verbally or written, you’re going to spend a little more time to see if there’s something that will make you change your mind. But what does it all mean? 

At the very top of the scale is Flawless. That one’s self-explanatory, so I’ll skip it and move on to VVS1 and VVS2.  By definition, it means a Very Very Slightly Included diamond. This particular diamond crystal has very, very tiny inclusions that a trained eye will have to really look hard to find. With a diamond of this grade, what you’re really trying to do is to see if what you’ve got is a Flawless diamond or not. The chances of it being Flawless is so remote that you look extra hard to find something - anything - and, it’s usually in there.  If the tiny, tiny inclusion is in the middle of the diamond, I’ll probably grade it a VVS2. But, if the inclusion is buried out along the edge of the girdle, I’ll probably call it a VVS1.

‘VS’ stands for Very Slightly Included. Whenever I look at a diamond, I’m always expecting to find something in it. With a VS quality diamond, it might take me a few seconds, but I’ll know pretty quick that it’s not Flawless or VVS, but the same rules apply here about the number and placement of the inclusions. VS1 is a small inclusion buried against the girdle while a VS2 is a small inclusion somewhere in the middle of the diamond.

From there we go to ‘SI’, Slightly Included 1 or 2, and then on to ‘I’, Included 1, 2, or 3. The same rules apply to these diamonds that have inclusions that are very noticeable to the trained eye. After that we come to what I call a ‘DB’ grade. What, you’ve never heard of the ‘DB’? That’s what I call a faceted diamond that really should have been ground up into the end of a drill bit. How do I make that an international standard?

Now what about the cut of the diamond? That’s gotten tricky here lately. For purposes of this discussion I’m only going to concentrate on the round brilliant cut diamond. How does a diamond cutter determine where to put all of those itty bitty facets? Well way back in 1919, a Polish engineer named Marcel Tolkowsky, who was born into a family of diamond cutters, discovered what is known as ‘the critical angle’ in a diamond crystal. With this discovery, he was able to develop what became the standard for cutting round brilliant cut diamonds around the world.  But, how do you judge the cut?

First off, remember that a faceted diamond starts out as a small, odd shaped, 63 million year old rock. No two are alike so every situation is unique. When a cutter is looking at his rock to decide how to cut it, for the most part he is looking at how to make it into the heaviest faceted diamond that it can be. Since diamonds are sold by carat weight, the bigger the diamond, the more it will bring.

So, in order to maximize the weight out of that odd shaped rock, sometimes the cutter will have to adjust angles and facets to accommodate the rough stone he is working with. Once finished, it will be judged against ‘The Tolkowsky Standard’ and be graded as excellent, very good, good, or poor against the Tolkowsky standard. But trust me, not every rock lends itself to the perfect cut and not every diamond cutter is capable of producing the perfect cut every single time.

But, there is an exception called ‘A Tolkowsky Cut Diamond’. What this refers to is the cutter wasn’t trying to maximize the weight, he was trying to maximize the cut to achieve the perfect diamond. And yes, those things are gorgeous - and expensive!

Since the late ‘80s, early ‘90s though, a lot of newer cuts have come on the market like the Star 129. This cut takes a different approach to Marcel Tolkowsky’s critical angle calculation, and the diamond is faceted differently to achieve maximum scintillation and they are gorgeous as well.  But to be honest with you, the cut grade kind of befuddles me because with computer and laser technology you can just about cut one of those shiny rocks into any shape you want nowadays. But regardless of the cut, the color and the clarity are still graded against GIA standards.

So, at the end of the day, what does this all mean? It means this; if you’re going to be in this business as a career choice, get as much gemological training as you can so you understand and trust what you are selling. These last several years we’ve all learned that just because a diamond comes from a supplier with a laminated document saying it’s an SI1, H-color, it’s on you - the seller - to guarantee that what you’re selling  is truly an SI1, H-color, cause you’re the one that’s gonna get sued, not them!

I was very fortunate to have been able to go to gemology school when I was 20 years old and just starting out in this business. It pains me to see unscrupulous persons out there bastardizing something that all of us in this industry hold dear - our reputations. In the last couple of months we’ve received numerous press releases from major diamond wholesalers that have announced they are no longer offering diamonds with sketchy certifications. Good for them. Now if we can just convince the rest of them.

And bench jewelers out there, it’s winter time and you know what that means - cracked callouses and fingertips. Order yourself some Mary Kay Satin Hand soap and it will keep that from happening. I’ve been using it for years and I swear by it. If you don’t have a Mary Kay rep, use mine.  You can reach McKensie at 615-924-9686.

Chuck is the owner of Anthony Jewelers in Nashville, TN. Chuck also owns CMK Co., a wholesale trade shop that specializes in custom jewelry and repair services to the jewelry industry nationwide. If you would like to contact Chuck or need a speaker or instructor for your next conference/event he can be reached at 615-354-6361, www.CMKcompany.com or send e-mail to This email address is being protected from spambots. You need JavaScript enabled to view it..