Diamond Types: What You Need (And Don't Need) To Know When Shopping

We've talked a lot about the four C's of diamonds: Cut, Color, Clarity and Carat. But as it turns out, we've been holding back a bit. There are actually five. The unsung C is "classification," or diamond type. Although it's less essential than the Big Four, it's important to know about. The mention of diamond type can surface during the shopping process and prove confusing or cause you to question the priorities you've set for choosing your perfect engagement ring. So let's lay it all out.

"Diamond type" means one thing to jewelers, and often something else to customers. For example: To gemologist, "cut" can mean the diamond's actual cut, or its number of facets, like the brilliant cut. Customers often understand it as the diamond's shape — like round, emerald or pear. We'll go over both of them here.

What diamond types are to gemologists

Diamond type can be confusing, not only because as far as gemologists are concerned, a particular diamond can be more than one diamond type.

It might help to think of a diamond's type as elemental.

Like, literally elemental. Every diamond forms from a base of carbon. But as it grows, atoms of other elements — mostly nitrogen — become included in that base. (If you're wondering, here's how diamonds are formed — and it's not from coal as many of us grew up thinking.) Although it's not apparent to the naked eye, those atoms can cluster together, affecting the color and appearance of the completed diamond.

A diamond's type will be assessed by an expert and noted on its GIA (Gemological Institute of America) certificate.

The different diamond types, explained

Here's what you should understand about diamond types: First and foremost, very little of this affects the process of buying a diamond online. That's because some of these types are extremely rare. Other types are more common with fancy colored diamonds, which you're probably not buying if you're planning on setting your stone in an engagement ring. So here what you need to know and what you don't, so things don't get overly complicated. After all, you have that proposal to worry about.

Type Ia Diamonds

Type Ia is the most common diamond type. A Type Ia diamond will emit a yellow tone because it contains large clusters of nitrogen throughout the crystal lattice. Nitrogen atoms absorb light in the blue range of the spectrum, which leads to their yellow/orange color. Type Ia diamonds are known for their characteristic fluorescence as well as absorption of infrared and ultraviolet light.

This type can be broken down further into Type IaA and Type IaB (but that has to do with the structure of the groups of nitrogen atoms, and it's a distinction that's really only relevant to gemologists).

Type IIa diamonds

Type IIa represents just 1 percent of all diamonds. This is what you think of, generally, when you think about diamonds. They contain almost no nitrogen, so they have no visible light absorption and no yellowish or brown tint. These diamonds form under extremely high pressure and have differing levels of fluorescence (which isn't necessarily a bad thing, for the record). Fancy colored diamonds of this type can be pink, gray, yellow, brown, light blue or light green. Many of the world's most famous diamonds are this type.

Type Ib diamonds

Type Ib diamonds represent fewer than 0.1 percent of natural diamonds. In these diamonds, nitrogen atoms are scattered throughout the crystal lattice as single atoms, not in clusters. They absorb a large amount of the light from the blue range of the color spectrum, which results in a very strong yellow color. True canary diamonds are Ib's.

Type IIb diamonds

Type IIb diamonds don't contain nitrogen, but they do contain boron. Boron absorbs light at the red end of the spectrum so most of these diamonds look blue or bluish grey. These diamonds are highly valuable, representing only 0.1 percent of natural diamonds.

What diamond types are to customers

For customers, a diamond's "type" tends to be less technical — farewell to those elements — and more general. For example, diamond type might refer to:

• Natural diamonds, which grow within the earth and are mined;


• Treated or enhanced diamonds, which are blemished or included diamonds whose clarity is corrected with advanced technology like lasers;


• Lab-created diamonds, which are also called synthetic diamonds. It's important to know that these diamonds aren't fake, like cubic zirconia — they're grown in laboratories under the same conditions as diamonds that develop within the earth and so are chemically the same as those found in the ground;


• Natural fancy color diamonds, some of the rarest diamonds. These diamonds emerge from the earth in colors like blue, green, pink or red.

Still have questions about the type of diamond you're thinking of buying? Reach out! Our expert gemologists are happy to answer any questions or walk you through Buy Diamond with Clarity's diamond policies. Keep in mind that we only ever sell GIA certified natural diamonds that have not been treated or enhanced in any way.