The Cleanliness Scale

Clarity is the characteristic that causes more confusion and anxiety among diamond buyers than any other. The idea that a diamond might have visible imperfections feels like a defect, and defects feel like something is wrong. But the reality of diamond clarity is more nuanced and far less concerning than most buyers expect. This guide explains exactly what clarity means, how the grades work, and where to land for the best value without sacrificing beauty.

What Clarity Actually Measures

Clarity measures the presence of inclusions and blemishes in a diamond. Inclusions are internal imperfections—tiny crystals, fractures, or structural irregularities trapped inside the diamond during its formation. Blemishes are external imperfections—scratches, nicks, or surface damage that occurred after the diamond was cut.

The clarity grade is determined by observing the diamond under 10x magnification and evaluating the visibility, size, nature, and position of any imperfections. The fewer and less visible the imperfections, the higher the clarity grade.

The GIA Clarity Scale

GIA grades clarity on a scale from Flawless (FL) to Included (I3). The scale has six main grades:

FL and IF — Flawless and Internally Flawless

These are the highest clarity grades, meaning no inclusions or blemishes are visible under 10x magnification by a trained gemologist. FL means completely clean; IF means no internal inclusions but may have minor surface blemishes visible under magnification.

These grades are rare and expensive. They represent perhaps 1-2% of all diamonds. Paying for FL or IF clarity means paying for perfection that is rarely visible to the naked eye. There are very few practical reasons to buy FL or IF clarity unless you want the absolute highest grade for its own sake.

VVS1 and VVS2 — Very Very Slightly Included

These grades indicate inclusions that are extremely difficult to see under 10x magnification, even for a trained observer. The inclusions might be tiny feathers, pinpoints, or clouds that are barely detectable at high magnification.

VVS diamonds are expensive, but the clarity difference between VVS and FL is invisible without intense magnification. The practical beauty of a VVS diamond and an FL diamond is identical to the naked eye.

VS1 and VS2 — Very Slightly Included

These grades indicate minor inclusions that are difficult to see under 10x magnification. The inclusions are visible but not obvious. VS1 inclusions might be slightly smaller or less visible than VS2 inclusions, but the practical difference is marginal.

VS1 and VS2 represent the practical ceiling for most buyers. Diamonds in this range are almost always eye-clean (no inclusions visible to the naked eye), and the price premium over lower grades is more modest than the premium from VS to VVS.

SI1 and SI2 — Slightly Included

These grades indicate inclusions that are noticeable under 10x magnification. The inclusions are visible to a trained observer without difficulty. SI1 diamonds are often eye-clean; SI2 diamonds may show inclusions to the naked eye in some lighting conditions or angles.

The key question with SI diamonds is whether they are eye-clean. A VS1 diamond costs more than an SI1 diamond of equivalent other qualities, but if the SI1 diamond is eye-clean, you are paying extra for clarity that does not affect the visible beauty of the stone.

I1, I2, and I3 — Included

These grades indicate inclusions that are obvious under 10x magnification and may also be visible to the naked eye. At these grades, inclusions can affect the transparency and brilliance of the diamond. I diamonds are generally not recommended for engagement rings unless the buyer is explicitly prioritizing budget and understands the trade-offs.

The Eye-Clean Standard

The single most important concept in diamond clarity is the eye-clean standard: a diamond is eye-clean if no inclusions are visible to the naked eye when viewed from the top (face-up) in normal lighting conditions at a normal viewing distance of approximately 20-30 centimeters.

Most VS1, VS2, and often SI1 diamonds are eye-clean. This means that buying a diamond above VS clarity buys something you cannot see. The beauty of the diamond is not affected. You are paying for theoretical perfection under magnification, not visible improvement.

What Types of Inclusions Look Like

Diamond inclusions vary widely in their appearance and impact:

• Feathers: Small fractures in the diamond. Usually white or transparent. Most feathers are not durability concerns unless they extend to the surface of the diamond.
• Clouds: Clusters of tiny pinpoint inclusions too small to see individually. A dense cloud can affect the transparency of the diamond, making it appear hazy or milky.
• Crystals: Mineral crystals trapped inside the diamond. Can be white, black (carbon), or colored. Black crystals are more visible than white ones.
• Needles: Long, thin mineral inclusions that look like tiny rods under magnification.
• Pinpoints: Single tiny white dots. The most common inclusion type and usually the least concerning.

Clarity and Shape Interactions

Different diamond shapes show inclusions differently. The rule: step-cut shapes (emerald and asscher) show inclusions more readily because of their large, open facets. Brilliant-cut shapes (round, oval, pear, marquise, princess) mask inclusions better because of their multiple small facets and light return.

For step-cut diamonds, aim for VS1 or higher. For brilliant-cut diamonds, VS2 is often perfectly clean, and SI1 can work well if the specific diamond is eye-clean.

Clarity and Price

Clarity premiums can be substantial. The price difference between a VS1 diamond and an SI1 diamond of equivalent other qualities can be 10-20%. The difference between VS1 and VVS1 can be another 15-25%.

For most buyers, VS1 or VS2 is the practical ceiling. Paying more for VVS or FL buys theoretical perfection that does not translate to visible beauty. If you are working within a budget, it is almost always better to put that money into cut quality or carat weight rather than clarity above VS.

Reading the Clarity Plot

On a GIA or IGI certificate, the clarity plot is a diagram showing the location, size, and type of inclusions in the specific diamond. This is more useful than the clarity grade alone because it shows you exactly what is inside the diamond.

When evaluating a clarity plot, look for:

• Inclusions near the center: More visible than inclusions near the edge.
• Colored inclusions: Black crystal inclusions are more visible than white ones.
• Dense clouds: Can cause haziness or milkiness that affects brilliance.

Lab-Grown Diamond Clarity

Lab-grown diamonds can have inclusions just like mined diamonds, but the types are often different. Lab-grown diamonds may have metallic inclusions from the growth process (visible as metallic flecks in HPHT diamonds) or strain patterns (which can affect color in some cases).

Always check the clarity plot on a lab-grown diamond certificate to understand what type of inclusions are present. A lab-grown diamond with SI1 clarity might have inclusions that are more or less visible than an SI1 mined diamond depending on the type.

At Aranc

We can help you evaluate clarity in the context of your specific priorities and budget. For most buyers, we recommend prioritizing eye-clean clarity (VS1, VS2, or SI1 if eye-clean) over paying for higher grades that do not affect visible beauty.