Diamond Clarity Chart

What Is Diamond Clarity, and What Does the Chart Actually Show?

Diamond clarity measures how free a stone is of internal inclusions and surface blemishes, graded on an 11-step scale that runs from Flawless (FL) at the top down through Internally Flawless (IF), Very, Very Slightly Included (VVS1, VVS2), Very Slightly Included (VS1, VS2), Slightly Included (SI1, SI2), and finally Included (I1, I2, I3) at the bottom. The chart is not a pass/fail test — it is a relative ranking of how much a diamond has been marked by nature during its formation, and by handling since, viewed under 10x magnification by a trained grader.

Almost every diamond has some inclusion or blemish; even the naming "flawless" refers only to what a trained eye can see at 10x, not to literal geological perfection. What the clarity chart is really useful for is comparison: it lets you weigh two diamonds against each other on a consistent, internationally recognized scale instead of relying on a seller's word that a stone is "clean."

The most important practical takeaway is that clarity grade and visible flaws are not the same thing. A diamond graded SI1 or even SI2 often looks completely clean to the naked eye, while a technically higher VS2 stone with an inclusion in an unlucky spot can occasionally show more. The rest of this guide breaks down what each grade band means, how the grading itself is done, and where "eye-clean" actually falls on the scale.

The GIA Diamond Clarity Scale, Grade by Grade

Flawless (FL) and Internally Flawless (IF) sit at the top of the scale. A Flawless diamond shows no inclusions or blemishes of any kind under 10x magnification; an Internally Flawless diamond has no inclusions but may show a very minor blemish on the surface, such as a tiny extra facet, that a polish could theoretically remove. Both grades are genuinely rare in the marketplace.

Very, Very Slightly Included (VVS1 and VVS2) diamonds contain inclusions that are difficult even for an experienced grader to locate under 10x magnification. VVS1 inclusions are typically smaller or better hidden than VVS2 inclusions, but both grades are considered extremely clean, and neither is visible without magnification.

Very Slightly Included (VS1 and VS2) diamonds have inclusions that are visible under 10x magnification with moderate to somewhat greater effort, but they are minor. This range is where most well-cut diamonds start to become reliably eye-clean to an unaided viewer at normal wearing distance, which is why VS1 and VS2 are among the most commonly chosen grades for engagement diamonds.

Slightly Included (SI1 and SI2) diamonds show inclusions that are noticeable to a trained grader under 10x magnification without much searching. Many SI1 stones, and a meaningful share of SI2 stones, still face up eye-clean depending on the type, size, and position of the inclusion — but SI2 is the grade band where the odds of a naked-eye-visible inclusion rise significantly, especially in larger stones.

Included (I1, I2, and I3) diamonds have inclusions that are visible to the unaided eye, and in the lower grades those inclusions can affect the stone's transparency or, in extreme cases, its durability. I1 stones sometimes still appear reasonably clean depending on the inclusion, but I2 and I3 diamonds reliably show visible flaws and are the least commonly used in fine jewelry.

How Clarity Is Actually Graded

A trained grader examines a loose diamond under 10x magnification using a binocular microscope, viewing it from multiple angles through both the crown (top) and pavilion (bottom) rather than a single glance. What matters is not just whether an inclusion exists, but its size, number, position, nature (a feather, crystal, cloud, or cavity, for example), and how much it contrasts against the surrounding diamond.

Position matters more than most people expect. An inclusion sitting directly under the table facet — the large flat top of the stone — is far more likely to be visible to the naked eye than the same-sized inclusion tucked near the girdle edge, where the facet pattern and mounting can help obscure it. This is exactly why two diamonds with the same clarity letter grade can look noticeably different in the hand.

Clarity grading is done on the loose stone before it is set, which is one reason a report matters: once a diamond is mounted, prongs and metal can hide the very characteristics — or the very flaws — that determine its grade. A grading report gives you a documented, independent record of what the stone looked like before it went into a setting.

"Eye-Clean": What It Means and Which Grades Usually Qualify

A diamond is generally called "eye-clean" when a person with normal vision cannot spot an inclusion at a typical viewing distance — arm's length, under normal indoor lighting — without magnification. It is a practical, real-world standard rather than an official clarity grade, and it depends on more than the letter grade alone.

As a general pattern, VS2 and better grades are eye-clean in the overwhelming majority of cases, SI1 diamonds are eye-clean more often than not, and SI2 is where results become genuinely inconsistent — some SI2 stones look completely clean, and others show a visible inclusion the moment you know where to look. Diamond size interacts with this: a small SI2 melee stone is far more forgiving than a large SI2 center stone, where the same inclusion covers more visual real estate.

Inclusion type also matters as much as the letter grade. A single well-placed crystal or feather near the girdle can leave a stone looking cleaner than its grade suggests, while a cluster of small pinpoints scattered across the table can make a technically higher-graded stone look busier than expected. This is exactly why photos or, ideally, an in-person look at the actual stone — not just the grade on paper — matters when clarity is a priority.

Clarity vs. the Other Cs: Why It's Only Part of the Value Equation

Clarity is one of the "4Cs" — cut, color, clarity, and carat weight — that together determine a diamond's overall quality and desirability, and it is often the C buyers overweight relative to its real visual impact. Cut quality has a far larger effect on how much a diamond sparkles than clarity does; a well-cut SI1 diamond will typically outshine a poorly cut VVS2 diamond in everyday lighting.

Carat weight also changes how much a given clarity grade matters. Inclusions become proportionally easier to see as a diamond gets larger, simply because there is more surface area to view them through, which is why buyers shopping for larger center stones often prioritize a cleaner clarity grade than they would for smaller accent stones or a smaller center stone.

Shape matters too. Step-cut shapes like emerald and asscher cuts have large, open facets and act like a hallway of mirrors that can make an inclusion more visible, while round brilliant and other faceted shapes scatter light in a way that helps hide minor inclusions. A buyer prioritizing an emerald cut may reasonably want to shop one clarity grade higher than they would for the same size in a round brilliant.

How to Read Clarity on a Real Grading Report

An independent grading report from a recognized lab — GIA, AGS, or IGI are the names to look for — states the clarity grade in writing and typically includes a plotting diagram: a simple map of the stone showing the type and approximate location of its clearest inclusions, using standardized symbols. Comparing the plot to the stone in hand (or in photos) is the most reliable way to understand exactly what you are buying.

A report is also the only way to confirm a clarity claim independently of the seller. Clarity cannot be verified from a listing photo or a verbal description alone, since lighting, macro photography, and even the angle of a photo can make a stone look cleaner or busier than it actually is. If a seller states a clarity grade without a report to back it up, treat that as a starting point for questions, not a confirmed fact.

Getting a Diamond's Clarity Looked At in San Antonio

If you are trying to understand the clarity of a diamond you already own — an inherited ring, an old engagement ring, a loose stone from a family collection — Lone Star Coins offers a free, no-obligation purchase evaluation at our San Antonio showroom. We examine the piece in person, reference any GIA, AGS, or IGI report that comes with it, and explain what we see in plain terms; a report helps but is not required to get an evaluation.

We are not a grading laboratory and do not issue certificates of our own, in diamonds or in anything else we evaluate — the same standard we hold for coins and watches. If a piece is significant enough to warrant a formal grading report and doesn't already have one, we will tell you that plainly rather than offer an in-house substitute. Walk in during business hours, no appointment necessary.