Diamonds and the 4Cs

It’s hard to talk about diamonds without someone bringing up the 4Cs. Back in the early 1940s, a guy named Robert M. Shipley established an institute called the Gemological Institute of America (GIA). He wanted to professionalize the jewelry trade and provide formal training to jewelers and sales people. He also saw a need to instill a stronger sense of ethics and standards in the industry.

The 4Cs came out of his training – he created them as a mnemonic device to help his students remember the four factors of a faceted diamond: color, clarity, cut, and carat weight. 

But he didn’t originally conceive of it as a marketing or sales term — just as a way for his students to learn. Diamond merchants had always used a 

variety of different, often vague terms to talk about their diamonds, and there was no consistency from one trader to the next. But as the terms became part of the American jewelry industry’s vocabulary, they also became the language of retail.

4Cs: The Basics

Here’s a quick guide to the 4Cs. And feel free to ask us questions – we love sharing our knowledge about diamonds.


Color is the second most important of the 4Cs. The less color a diamond has, the higher its grade will be.


This should be your least-important concern. Natural diamonds have tiny, microscopic imperfections. But good cut and color more than compensate!


Why This Matters

For many people, buying an engagement ring is their first experience with buying diamonds. It can feel a bit intimidating. But it doesn’t have to be! With some basic diamond knowledge in your pocket, you’re ready to explore your first diamond purchase, and you’re going to do great.

Besides, the A&J team is here to walk you through the experience, just as we have for at least a thousand couples before. We’ll happily answer all your questions, we’ll make sure you’re comfortable each step of the way, and we’ll make it fun for you.

But here’s the most important thing. It’s not about the size, or the price, or the certificate. If the diamonds is beautiful to you, then it’s beautiful. Because your engagement should be about the experience.

Quick 4Cs FAQ

Tell Me More About Cut

A diamond cutter is a sculptor. Once experienced, they develop an incredible affinity for the rough stones, and can tell, just by staring at them, where and how to cut. This is incredibly challenging work. Imagine the stress of taking three or four carats of diamond rough, and being responsible for removing much of that weight – and value! – in order to produce a smaller, but much more beautiful, gem.

How they cut the stone is about much more than the shape. They must consider the balance and proportions of the stone. They work to achieve precise geometries, because the way the stone is faceted determines how it will interact with light – which is what gives a diamond its sparkle. Rough diamonds don’t have any sparkle at all. They are dull and bulky. All the sparkle and shine comes from a diamond polisher (that’s what a cutter is often called) removing thin layers of diamond material to reveal the magnificent stone in the middle.

This is why cut is the most important of the 4Cs. A magnificent cut can make a mediocre rough diamond into an outstanding diamond. A poor cut can turn a beautiful stone into a sad shadow of what it was meant to be. When you look at a diamond, try to imagine the skill – and courage! – it takes to shave away at a stone and turn it into something so beautiful. And remember this: the cut is everything.

Tell Me More About Color

Many people think white diamonds are the most rare diamonds of all, but they’re not! The most rare diamonds of all are actually blue and red. In fact, most diamonds live in the middle of the color range, on a spectrum from deepish yellow to lightish gray.

But the closer a diamond gets to colorless, the rarer it is, and that is why the color grading system gives the best grades to the most colorless diamonds. 

The color scale goes from D to Z. You might be wondering, what happened to A through C? When the GIA was creating its color scale, there were a bunch of other diamond grading practices in use, and they included scales like A, AA, AAA, B, C, etc. So GIA jumped straight to D.

The most expensive diamonds will be in the D, E, and F colors, and the majority of diamonds sold in jewelry are in the D through J range.

Cut also has some influence on the color rating. For instance, a round brilliant (that’s the name of a cut) diamond will hide the yellow color much better than a more elongated diamond. In fact, if you are looking at a round, emerald, or Asscher cut, you can often go as low as a J grade before you start seeing noticeable color.

But here’s the most important thing to remember. Your diamond is about you. If you love a diamond, don’t let anyone tell you that it’s not the perfect diamond for you! You’re not buying a certificate, you’re buying a gem, a symbol, an experience. You get to decide what color diamond is the right color for you.

Tell Me More About Clarity

Diamonds that are grown in the earth have spent a millennia (or more) deep down in the crust. So it’s hardly any surprise that they are filled with little spots and flecks and pockets. In the diamond world, these are referred to as inclusions. In the 4Cs, clarity is all about measuring how many inclusions are present in the stone.

If you think back to those talented cutters for a moment, cutters carefully evaluate rough diamond before they start, and they work around major inclusions. They may take a 4.0 carat rough and turn it into two perfect 1.0 carat stones with very few inclusions, rather than trying to create one 3.0 carat stone with a lot of inclusions.

Most inclusions are not visible to the naked eye. But under magnification they can be seen, and they become part of the identity of your diamond, similar to a thumb print. The grading will be based on what is referred to as “eye clean,” or what can be seen with the naked eye.