Almost every natural diamond carries tiny internal features born during its formation deep in the earth, and clarity is the measure of how few of these there are and how visible they remain. These features are often called nature's fingerprints, because no two diamonds share the same pattern. The encouraging truth for buyers is that most of them are invisible without magnification, which means clarity is the C where you can often save the most while losing nothing the eye can see.
In short: aim for an eye-clean diamond rather than a flawless one. The VS to SI1 grades are almost always clean to the naked eye yet cost a fraction of VVS or Flawless stones that look identical once set. Step up to VS2 or better only for emerald and Asscher cuts. Read this beside our complete diamond buying guide for the full picture.
Inclusions vs Blemishes
Clarity characteristics come in two kinds, and the GIA report distinguishes between them. Understanding the difference helps you see why two diamonds of the same grade can still look quite different, and why the position of a feature matters as much as its size.
Common Inclusions
Inclusions are internal, formed inside the diamond as it grew. They include tiny crystals, feathers, clouds, needles and pinpoints. A small inclusion sitting directly under the table, the large flat top facet, is far more significant than a larger one tucked near the girdle where the faceting and the setting can hide it. This is why a well-chosen SI1 can look cleaner than a carelessly selected VS2.
Common Blemishes
Blemishes are external, confined to the surface, such as scratches, nicks, naturals or polish lines. Many are minor and some can be gently polished away. GIA assesses both inclusions and blemishes under ten times magnification, and the grade reflects their size, number, position, nature and relief, in other words how easily they can be seen.
The GIA Clarity Scale, FL to I3
The scale runs from Flawless at the top to Included at the base, with several grades in between. Here is what each one means and, more usefully, whether a stone in that grade is likely to be clean to the naked eye.
- Flawless (FL) and Internally Flawless (IF): no inclusions visible under ten times magnification, exceptionally rare and priced accordingly.
- Very Very Slightly Included (VVS1 and VVS2): minute inclusions that are very difficult even for a trained grader to locate under magnification.
- Very Slightly Included (VS1 and VS2): minor inclusions, difficult to see under magnification and invisible to the naked eye.
- Slightly Included (SI1 and SI2): noticeable under magnification, with SI1 usually eye-clean and SI2 sometimes showing an inclusion to a careful eye.
- Included (I1, I2 and I3): inclusions visible to the naked eye that can affect transparency and, in the lower grades, durability.
| Grade | Full name | Under 10x magnification | Eye-clean? |
|---|---|---|---|
| FL and IF | Flawless and Internally Flawless | No inclusions, surface only at most | Yes, always |
| VVS1 and VVS2 | Very Very Slightly Included | Extremely hard to find | Yes, always |
| VS1 and VS2 | Very Slightly Included | Minor, hard to see | Yes, virtually always |
| SI1 | Slightly Included | Noticeable | Usually yes |
| SI2 | Slightly Included | Easily seen | Sometimes, check carefully |
| I1 to I3 | Included | Obvious | No, visible to the eye |
Eye-Clean: The Concept That Matters Most
For most buyers, the only question that truly matters is whether a diamond is eye-clean, meaning no inclusions are visible to the naked eye at a normal viewing distance. A diamond does not need to be Flawless to look flawless on the hand. This is why the VS to SI1 range is the value sweet spot: a VS1, VS2 or carefully chosen SI1 diamond is almost always eye-clean, yet costs a fraction of a VVS or Flawless stone that looks identical once set.
Where the Value Sweet Spot Sits
The skill lies in selecting an SI stone whose inclusions sit toward the edge rather than directly under the table, and that is exactly what we do for you under magnification. Money saved on clarity you cannot see is far better spent on cut, the one C that drives sparkle, or kept for a touch more carat weight. The colour grades guide applies the same logic to colour.
Why Shape Changes the Clarity You Need
Faceting decides how much clarity you should buy. Brilliant cuts such as round, oval and cushion have busy, sparkling facets that break up light and help disguise small inclusions, so a lower clarity grade can still face up clean. Step cuts are the opposite: an emerald or Asscher cut has a large, open table and long parallel facets that act like clear windows into the stone, revealing inclusions a brilliant cut would hide. For these shapes we recommend stepping up to VS2 or better, as our diamond shapes guide explains.
The Most Common Inclusions, and Which to Watch
Inclusions come in several named types, and knowing them helps you read a GIA report with a confident eye. Crystals are tiny minerals trapped inside the diamond and can be colourless, dark or even a soft pink. Feathers are small internal fractures that look like fine cracks. Clouds are hazy groups of microscopic pinpoints, needles are slender rod-like inclusions, and twinning wisps are ribbon-like features formed as the crystal grew. Most are completely harmless and invisible once the stone is set.
When an Inclusion Affects Durability
A small number of inclusions are worth a closer look. A large feather that reaches the surface, more common in the I grades, can in rare cases be a weak point, so it deserves a jeweller's eye before setting. A dense cloud can very occasionally soften a diamond's transparency, giving a faintly milky look. These are the exception, not the rule: across the VS to SI1 range the inclusions are minor and pose no concern, which is exactly why this range is such dependable value.
Reading a Clarity Plot
On a full GIA report you will find a clarity plot, a diagram of the diamond marked with the type and location of each inclusion and blemish. Red symbols show internal inclusions and green show surface blemishes, and a key names each one. Use it to confirm where the features sit, favouring stones whose marks fall near the girdle rather than under the table, and to check that the report belongs to the exact stone in front of you. The plot is a unique fingerprint, which is part of what makes a certified diamond so easy to value and insure.
Clarity is the C where you can pay only for what your eye can see, not for what a loupe reveals.
Aim for eye-clean, lean on the VS to SI1 range for brilliant cuts, and step up only for emerald and Asscher styles. Every diamond at IDC Cayman comes with a GIA report whose clarity plot maps each characteristic precisely, so you can see exactly what you are buying. Browse our certified diamonds and our engagement rings, then visit our boutique in George Town, Grand Cayman to view stones under magnification yourself with no appointment needed. Every purchase is entirely tax-free, and we are always happy to help you in person.