Diamond Clarity: What Grade Do You Actually Need?
Clarity grades run Flawless to Included, judged at 10x on a diamond's inclusions and blemishes.
Most diamonds sold in stores fall in the VS to SI middle of the scale.
VS2 and SI1 are where most buyers land. Both are usually eye-clean in a brilliant cut.
Shape changes what eye-clean requires. A brilliant cut hides what a step cut like emerald or Asscher reveals.
Eye-clean appears on no grading report. Confirming it means reading the clarity plot or examining the stone.
Diamond clarity describes the inclusions and blemishes a trained grader finds in a stone at 10x magnification. Almost every natural diamond has some: a mineral speck, or a small fracture formed while the crystal was still growing. The grade describes those characteristics. It does not describe how the stone reads on a hand. This guide covers the eleven-grade scale, how graders arrive at a letter, and the factors that decide whether an inclusion is visible once the diamond is set.
- What Does Diamond Clarity Actually Measure?
- How Does the GIA Clarity Scale Work?
- What Does "Eye-Clean" Actually Mean?
- Which Clarity Grade Should You Buy?
- How Does Diamond Shape Affect Clarity?
- What Types of Inclusions Should You Know About?
- How Do You Verify a Diamond Is Actually Eye-Clean?
- Is Flawless Clarity Worth It?
What Does Diamond Clarity Measure?
Clarity measures the size, number, position, and visibility of a diamond's inclusions and blemishes. A trained grader assigns it through a 10x loupe. Anything too small to find at that power has no effect on the grade.
An inclusion is internal, formed inside the stone as it grew. A blemish is external only: a scratch, a nick, a patch of polish left by the cutting wheel.
Position governs appearance more than any other factor. A grade compresses all of them into a single letter and number. Clarity is one of four grades on a report. Of the four, it affects appearance less than cut does. The 4Cs guide takes each of the four in turn.
How Does the GIA Clarity Scale Work?
Eleven grades sit inside six categories, Flawless at the top and Included at the bottom. Most diamonds sold in stores land in the VS-to-SI middle. Telling one grade from its neighbor takes a trained eye and a 10x loupe.
Flawless shows no inclusions and no blemishes at 10x. Internally Flawless shows no inclusions but allows minor surface blemishes. VVS1 and VVS2 are difficult for a skilled grader to find. VS1 and VS2 range from difficult to fairly easy to spot. SI1 and SI2 are noticeable at 10x. I1 through I3 are obvious without a loupe and can reduce transparency and brilliance.
Graders weigh five factors: size, number, position, nature, and color or relief. Position does the most work. A white crystal near the girdle can vanish under a prong. The same crystal under the table sits in the line of sight.
Richard Liddicoat built the scale in 1953, decades after GIA founder Robert Shipley coined the phrase 4Cs. Georgian diamonds were cut, sold, and inherited for more than a century before any of it existed. Later Victorian and Edwardian stones predate it as well, by a few decades to the better part of a century. This is why many antique cut diamonds carry no grading report.
What Does "Eye-Clean" Actually Mean?
Eye-clean means no inclusion is visible to normal vision, unmagnified, from about ten inches away. The term appears on no certificate and in no grading system. It describes the condition most buyers are actually asking about.
A report can call a stone VS2 without indicating whether anything will be visible. Eye-clean status depends on the characteristic itself, where it sits, how dark it is, and how large the stone is.
Surface dirt is a more common cause of a dull diamond than an inclusion. Skin oil and hand lotion dull a stone faster than a small feather does. A dull stone usually needs nothing more than cleaning.
Position decides most of it. An SI1 with a feather under a prong can look cleaner than a VS2 with a dark crystal centered under the table. Magnification settles the question in a minute.
Which Clarity Grade Should You Buy?
VS2 and SI1 are where most buyers land. Both are commonly eye-clean in a brilliant cut. Fewer of the eleven grades matter to a finished ring than the scale suggests.
VS1 and above buys certainty. Stones at those grades are nearly always eye-clean regardless of shape or size. That makes them the safe floor for a diamond bought sight unseen. VS2 is the common landing point and is usually invisible without magnification.
At SI1 the individual stone matters more than the report. Many are eye-clean. Some have a crystal parked under the table. The grade alone does not distinguish them. The I grades are visible without a loupe by definition and can affect transparency, and near the surface, durability. Filigree's standing practice is to pass on stones with visible inclusions unless the piece presents unusual value.
Larger diamonds have larger facets. Those facets magnify whatever sits beneath them. The grade should step up with the size.
The scale assumes fewer inclusions is better. One category sets that assumption aside entirely: salt and pepper diamonds are bought for their inclusions and are generally sold ungraded. Filigree's diamond engagement rings run from antique through modern stones. The full engagement ring selection is the wider view.
How Does Diamond Shape Affect Clarity?
Shape changes what clarity grade a diamond needs to read as eye-clean. Brilliant-cut shapes scatter light across dozens of facets. That scattering breaks up the eye's ability to settle on an inclusion. Step cuts do the opposite.
Round brilliants, ovals, cushions, radiants, marquises, and pears use a brilliant facet pattern that throws light in every direction. That flashing is why a genuinely eye-clean SI1 is common in these shapes.
Emerald and Asscher cuts are step cuts, with long parallel facets that produce broad flashes instead of scattered sparkle. The effect is closer to a hall of mirrors. An inclusion has nowhere to hide. VS1 or VS2 is the working target in a step cut rather than SI.
Old mine and old European cuts were cut by hand, with larger open culets and less uniform faceting than a modern round brilliant. That construction lets color and inclusions show more readily at a given grade. This is trade knowledge rather than a GIA position. The guide to old European, old mine, and rose cuts covers what that construction looks like.
What Types of Inclusions Should You Know About?
Five kinds come up constantly: feathers, pinpoints, clouds, crystals, and twinning wisps. Reports name each characteristic with a code and a location on the stone. Most affect appearance. A few affect durability.
A feather is a small internal fracture, named for its wispy look. The one worth asking about reaches the surface at the girdle, where a knock has somewhere to travel. A pinpoint is a tiny crystal speck, invisible without magnification. A cloud is a cluster of pinpoints: a light one does nothing noticeable, and a dense one can look hazy. A crystal is another mineral trapped inside as the diamond grew, either colorless or dark. A black crystal is the most visible for its size. A twinning wisp is a ribbon of mixed pinpoints, clouds, and crystals along a growth-twin plane.
Two disclosed treatments change how clean a diamond looks without changing any of the mechanics above. Laser drilling opens a channel to a dark inclusion and lightens it. The result is permanent and detectable under magnification. Fracture filling fills a surface fracture with a glass-like substance so it stops catching light. It is not permanent. Both must be disclosed.
How Do You Verify a Diamond Is Eye-Clean?
Two steps confirm eye-clean status: read the clarity plot, then examine the cleaned stone face-up in ordinary light.
The clarity plot is the diagram on the report. It matches the stone's real shape and carries color-coded symbols, red for inclusions and green for blemishes, in two views: the crown from above and the pavilion below.
Symbols near the middle sit under the table, in the line of sight. Symbols at the edge sit near the girdle, where a prong may cover them. A stone with several small symbols around the edges often looks cleaner than one with a single symbol centered, at the same grade.
GIA reports carry a hologram, a security screen, and microprint. The report number is laser-inscribed on the girdle. The inscription should match the paper. Both should then be checked against GIA's Report Check tool online. Fluorescence does not cause haziness by itself. In a few strongly blue-fluorescent stones it can amplify existing graining into a milky look. A report noting strong fluorescence is worth confirming in daylight.
Is Flawless Clarity Worth It?
Rarity and visible difference are separate questions. The top of the clarity scale is where the gap between them is widest. For a ring worn daily, a Flawless stone and a well-chosen VS stone look the same without a loupe.
Flawless means no inclusions and no blemishes at 10x. Internally Flawless means the interior is clean, with only minor surface blemishes remaining. Only a small fraction of gem-quality diamonds qualify for either grade. The rarity is genuine.
Collectors buy the top of a scale for that rarity, particularly for a diamond bought as an object in its own right, to keep unset or pass down. It is truly investment grade and for those that want the best of the best. For most buyers, its reasonable to step down in clarity to find additional carat size and or value.
For daily wear the case is thinner. A VS1 stone and a Flawless stone look identical on a hand in every light to an untrainted eye. Cut affects how a diamond handles light more than any move up the clarity scale does. Buying the top of the scale buys rarity rather than a visible difference.
Vintage Diamond Cuts: Old European, Old Mine & Rose
How old European, old mine, and rose cuts hide or reveal what's inside them, and what to look for in each.
Read the Guide →Salt & Pepper Diamonds Explained
The one category where more inclusions is the point, not the exception.
Read the Guide →April Birthstone: Diamond
The stone's full story, from ancient lore to modern grading.
Read the Guide →Reading a clarity grade
Diamond clarity grades the inclusions and blemishes a grader finds at 10x, on an eleven-grade scale from Flawless to Included. Most stones sold fall in the VS-to-SI middle, and VS2 and SI1 are where most buyers land because both are commonly eye-clean in a brilliant cut. The grade records what a loupe found. Whether any of it is visible depends on three things: where the characteristic sits, the shape of the cut, and the size of the stone. Step cuts need a higher grade than brilliants, larger stones need a higher grade than smaller ones, and eye-clean status is confirmed by reading the clarity plot and examining the stone rather than by the grade alone.
Filigree's diamond engagement rings run across antique, estate, and modern stones. The April birthstone guide covers the stone itself.
See the Difference for Yourself
Browse diamond engagement rings spanning antique cuts to modern brilliance, shipped nationwide from our Minneapolis shop.
Tuesday–Friday 11AM–6PM · Saturday 11AM–5PM
Diamond Clarity, Answered
Does diamond shape affect what clarity grade I need?
Yes. Brilliant-faceted shapes like round, oval, and cushion scatter light and hide small characteristics well, so SI1 is often eye-clean. Step cuts like emerald and Asscher show the same inclusion plainly. Aim a grade or two higher in those shapes.
Is a diamond's clarity grade the same as how clean it looks?
No. The grade describes what a trained grader sees at 10x. How clean a stone looks face-up depends on where the characteristic sits, what it is, how dark it is, and how large the diamond is.
Can two diamonds with the same clarity grade look different?
Yes, often. GIA weighs size, number, position, nature, and color or relief together. A single grade can therefore describe several different inclusion patterns.
Does fluorescence affect a diamond's clarity or appearance?
Rarely. Fluorescence does not cause haziness by itself. In a few strongly blue-fluorescent stones it can amplify graining into a milky look. A report noting strong fluorescence is worth confirming in daylight.
How do I verify a GIA report is authentic?
Find the report number laser-inscribed on the diamond's girdle, visible under magnification. Match it to the number on the report, then confirm both against GIA's Report Check tool online.
