Diamond Clarity Guide

July 29, 2025

No diamond is completely perfect. Most have small, natural imperfections known as “inclusions”. In the diamond world, “Clarity” refers to the presence or absence of these inclusions.

In this guide, we’ll describe the nuances of diamond clarity, how the grading system works, and what to keep in mind when choosing a diamond. Whether you want something completely clean or simply eye-clean (that is, having no visible blemishes to the naked eye), having a good handle on clarity helps you shop smarter.

What Is Diamond Clarity?

Diamond Clarity refers to the presence of imperfections in or on a given stone. These imperfections can be surface level, or within the stone itself. Surface level imperfections are known as blemishes, while interior imperfections are known as inclusions.

Inclusions are natural byproducts of how diamonds form, either in the earth or in a lab. Most are so small you won’t notice them without magnification—and in many cases, they have no real impact on the diamond’s look with the naked eye. While blemishes can have natural causes, they can also come about from the diamond cutting and polishing process (taking a raw stone and processing it into a finished gem).

Clarity grading helps give a standard way to talk about how visible these imperfections are when viewed under 10x magnification.

The GIA Clarity Scale

The GIA has created a standardized scale to judge a given diamond’s clarity level. The scale ranges from Flawless (FL) to Included (I3) and includes 11 specific grades. The grades reflects how many inclusions or blemishes are present, where they’re located, and whether or not they can be seen with the naked eye.

Here’s a simple breakdown:

FL (Flawless): No inclusions or blemishes visible under 10x magnification. These stones are extremely rare.
IF (Internally Flawless): No inclusions, only very minor surface blemishes under magnification.
VVS1 – VVS2 (Very Very Slightly Included): Inclusions are extremely difficult to spot, even with a loupe.
VS1 – VS2 (Very Slightly Included): Small inclusions, only visible under magnification; inclusions in this level are considered minor.
SI1 – SI2 (Slightly Included): Inclusions are more noticeable under 10x, and some may be visible without magnification.
I1 – I3 (Included): Inclusions are obvious and can affect how the diamond looks or sparkles.

Between many of these grades, the differences are subtle—especially to the naked eye. What matters more is how the diamond looks in person, not just what’s on paper.

What Causes Inclusions and Blemishes?

Inclusions are a natural part of how diamonds form. Deep within the earth—or in a lab for lab-grown stones—diamonds develop under intense heat and pressure. During that process, tiny imperfections can get trapped inside the crystal structure. These internal markings are called inclusions, and they might take the form of small crystals, wispy fractures (known as feathers), or clusters of pinpoints that look like a soft cloud.

Some inclusions are light and hard to detect, while others might be darker and more noticeable. It all depends on their size, shape, position, and how transparent the diamond is.

Blemishes, on the other hand, are surface-level imperfections. These usually come from the cutting and polishing process, or sometimes from normal wear over time. A blemish could be a faint scratch, a tiny chip near the edge, or a minor abrasion on the surface.

It’s worth noting that inclusions and blemishes are extremely common—nearly every diamond has some. And in most cases, they don’t affect how strong or beautiful the stone is. They’re simply a natural part of what gives each diamond its own unique fingerprint.

How Clarity Affects Appearance

In reality, most people just want a diamond that looks clean to the naked eye—and you can usually get that without paying for the highest clarity grade.

Here’s what can influence how visible an inclusion is:

Diamond size: Inclusions stand out more in larger stones. If you’re going above 1 carat, clarity starts to matter a bit more.
Shape and cut style: Step cuts like emerald and Asscher have large, open facets that can make inclusions easier to spot. Brilliant cuts like round or oval tend to hide them better because of how they reflect light.
Inclusion placement: Inclusions in the center of the diamond (under the table) are more visible than ones near the edges or pavilion.

If the inclusion is small, off-center, and blends in well, you can often get a better price without sacrificing looks.

Clarity, Cost, and How It Stacks Up Against the Other Cs

Like the other Cs, clarity plays a role in a diamond’s price—but that doesn’t always mean higher is better. Flawless and Internally Flawless diamonds are priced at a premium because they’re rare, not necessarily because they look noticeably better to the naked eye. In fact, most people can’t tell the difference between an IF and a VS1 without magnification.

That’s why many buyers focus on the VS2 to SI1 range. If the diamond is well-cut and eye-clean, you can often get more value by putting your budget toward cut quality or carat weight instead.

It’s worth pointing out that cut is arguably the most important C when it comes to how a diamond actually looks. The way a diamond is cut directly affects how it reflects light—how much it sparkles, how bright it appears, and how lively it feels overall.

A slightly included diamond with an excellent cut will almost always outshine a flawless one that’s poorly cut. So while clarity matters, it’s just one part of the bigger picture. Seeing the stone in person can also make a big difference—two diamonds with the same clarity grade can look very different depending on the size, position, and type of inclusion.

Item added to your cart