Diamond Clarity Explained: What Eye-Clean Really Means

Diamond clarity is one of the easiest characteristics to overspend on. A grading report can tell you how noticeable a diamond’s inclusions are under magnification, but it cannot tell you by itself whether the diamond will look clean, bright and beautiful in everyday life.

Two diamonds can receive the same clarity grade and look completely different. One may appear clean without magnification, while the other has a dark crystal under the table, a hazy cloud or a surface-reaching feature that deserves closer inspection. The goal is not simply to buy the highest grade. It is to choose a diamond that is eye-clean, transparent and structurally suitable without paying for rarity you cannot see.

What does diamond clarity measure?

Clarity describes internal characteristics, called inclusions, and external characteristics, called blemishes. When a diamond is graded, the examiner considers the size, nature, position, relief and number of those characteristics under 10× magnification.

That last detail matters: clarity is a laboratory grade, not a promise about what you will see with the naked eye. A tiny inclusion that is obvious under magnification may disappear completely at normal viewing distance. A darker inclusion in a prominent location may be easier to notice even when the report shows the same overall grade.

The diamond clarity scale, explained

FL and IF: Flawless and Internally Flawless

Flawless diamonds show no inclusions or blemishes to a skilled grader at 10× magnification. Internally Flawless diamonds show no internal inclusions, although minor surface blemishes may be present. These grades are exceptionally rare and command premiums because of that rarity.

They are not automatically brighter than lower-clarity diamonds. Light performance is driven primarily by cut quality and facet precision. A beautifully cut VS diamond can look more brilliant than a poorly cut flawless diamond.

VVS1 and VVS2: Very, Very Slightly Included

VVS inclusions are minute and difficult for a skilled grader to see at 10×. These diamonds almost always look completely clean without magnification. The price premium is usually buying rarity rather than a visible improvement.

VS1 and VS2: Very Slightly Included

VS inclusions are minor under 10× magnification. This range often provides an excellent balance of cleanliness and value. Many VS1 and VS2 diamonds are comfortably eye-clean, although a larger diamond, a step cut or an unusually dark inclusion can make closer review worthwhile.

SI1 and SI2: Slightly Included

SI inclusions are noticeable to a trained grader under 10×, but the category contains a wide range of appearances. Some SI1—and selected SI2—diamonds can look clean in real life. Others show obvious crystals, clouds, feathers or transparency issues.

This is where expert selection creates the most value. The grade alone is not enough; the actual diamond, video and plotting diagram need to be considered together.

I1, I2 and I3: Included

Inclusions in the Included range are obvious under magnification and may affect transparency, brilliance or durability. Some I1 diamonds can still have an attractive appearance for the right purpose, but engagement-ring center stones in this range deserve careful inspection. I2 and I3 grades typically involve compromises that are readily visible.

What does “eye-clean” actually mean?

“Eye-clean” is not an official laboratory grade. It is a practical description meaning that inclusions are not readily visible without magnification under normal viewing conditions. That definition depends on several variables:

• The viewer’s eyesight
• The distance from which the diamond is observed
• The lighting
• The diamond’s size and shape
• The location, color and relief of the inclusion
• Whether the diamond is loose or mounted

When I describe a diamond as eye-clean, I am interested in normal face-up viewing—not whether someone can find a pinpoint after holding the stone inches from their eye under harsh lighting.

Why two diamonds with the same clarity grade can look different

A clarity grade summarizes the combined effect of several characteristics. It does not mean every diamond in that grade has the same inclusions or the same visual result.

A small pale feather near the edge may be difficult to notice face-up, while a dark crystal beneath the center of the table can draw attention immediately. A scattered cloud of microscopic inclusions may not look like a single obvious mark, yet in some stones it can reduce transparency and make the diamond appear sleepy.

This is why shopping by a filter such as “SI1 or better” is only the beginning. The clarity grade narrows the field; it does not select the best stone.

Inclusion location matters

Inclusions beneath the table are often easier to see because the table is the diamond’s largest window. Dark crystals, knots or reflective features in that area may be more noticeable than pale characteristics near the perimeter.

Features near the girdle or pointed corners require a different kind of review. A feather that reaches the surface is not automatically dangerous, but its size, orientation and placement matter. Large surface-reaching feathers, cavities or chips near vulnerable areas may raise durability concerns—especially in shapes with points or corners such as pear, marquise and princess cuts.

Common clarity characteristics

• Crystal: A mineral crystal enclosed inside the diamond. It may appear colorless, dark or reflective.
• Feather: An internal break that can appear white or transparent. Its importance depends on size, orientation and whether it reaches the surface.
• Cloud: A grouping of tiny pinpoints. Small clouds are often harmless, while dense or widespread clouds can sometimes affect transparency.
• Needle: A slender crystal that may be difficult to see without magnification.
• Pinpoint: A very small crystal that appears as a dot under magnification.
• Cavity: An opening created when part of an included crystal falls out during polishing. Its location and size deserve attention.
• Chip: A shallow opening on the surface, often near the girdle or a facet junction.

The name of an inclusion does not determine whether the diamond is good or bad. A feather can be insignificant or concerning. A cloud can be invisible or reduce transparency. The actual size, relief, position and effect on the diamond matter more than the label.

Diamond size and shape affect clarity

Larger diamonds make inclusions easier to observe because there is more surface area and a larger viewing window. A VS2 that looks completely clean at one carat may deserve closer inspection at three or four carats.

Shape matters as well. Round brilliants use strong sparkle and contrast to hide many small inclusions. Cushion, radiant, oval and pear diamonds can also conceal characteristics effectively, depending on the facet pattern. Emerald and Asscher cuts have broad, open step facets that make internal characteristics easier to see, so buyers often prefer a higher clarity threshold for those shapes.

Can clarity affect sparkle?

Most inclusions in an eye-clean VS or carefully selected SI diamond will not noticeably reduce sparkle. Cut quality remains the larger driver of brilliance, fire and scintillation.

Clarity becomes a light-performance concern when inclusions are extensive enough to reduce transparency or interrupt light travel through the stone. Dense clouds, widespread graining or numerous reflective inclusions can sometimes make a diamond look milky, hazy or dull. A report may help identify the characteristics, but video and expert inspection reveal how the diamond actually performs.

Natural and lab-grown diamond clarity

Both natural and lab-grown diamonds can contain clarity characteristics. Their formation environments differ, so the types and patterns of inclusions may differ as well. Natural diamonds may contain mineral crystals, feathers and clouds. Lab-grown diamonds may show growth remnants, metallic inclusions, graining or strain-related patterns depending on how they were produced.

The buying principle is the same: do not stop at the printed grade. Evaluate whether the stone is eye-clean, transparent and free from characteristics that create an avoidable durability concern.

What clarity grade should you buy?

There is no single grade that is right for every diamond, but these guidelines are useful:

• FL–VVS: Choose these when rarity or an exceptionally clean report is personally important. The visual advantage over a clean VS diamond may be minimal.
• VS1–VS2: Often the safest value range for buyers who want a reliably clean appearance without paying for extreme rarity.
• SI1: Can offer excellent value when the diamond is confirmed eye-clean and transparent.
• SI2: Requires selective buying. Attractive examples exist, but appearance and durability vary widely.
• I1–I3: Review carefully for visible inclusions, transparency and durability implications.

For emerald and Asscher cuts, very large stones or buyers with exceptional visual sensitivity, moving higher in clarity can be worthwhile. For a brilliant-cut diamond with a well-placed pale inclusion, a lower grade may offer the same face-up beauty for less money.

How I evaluate clarity at Osiris Diamonds

I begin with the grading report, but I do not approve a diamond from the clarity grade alone. I review the inclusion plot when available, study high-resolution video, check face-up visibility, look for haze or reduced transparency and consider whether any characteristic could create a durability concern.

The best clarity grade is not necessarily the highest one. It is the lowest grade that still gives you the clean, transparent and durable diamond you expect—allowing more of the budget to go toward cut quality, size or the setting.

If you would like help comparing specific stones, contact Osiris Diamonds for a personal review. You can also read how diamond color appears in real life or browse available lab-grown diamonds.