Diamond clarity: a practical guide for buyers
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Clarity is one of the four C's, the grading system used to assess diamonds. Cut, colour, clarity, carat. Of the four, clarity is probably the one buyers overpay for most often.
Here's what it actually is, what the grades mean, and which ones are worth paying for.
What clarity measures
Clarity is a measure of how clean a diamond is on the inside and outside. Internal flaws are called inclusions. External flaws are called blemishes. Both are graded by looking at the stone under 10x magnification.
The key word is magnification. Most inclusions can only be seen under a jeweller's loupe. In normal life, even diamonds with mid-tier clarity grades look completely clean to the naked eye.
The clarity scale
The standard scale, established by GIA and used by every reputable lab including IGI:
- FL (Flawless). No inclusions or blemishes visible at 10x magnification. Extremely rare. Less than 1% of diamonds.
- IF (Internally Flawless). No internal inclusions visible at 10x, may have very minor surface blemishes.
- VVS1 / VVS2 (Very Very Slightly Included). Tiny inclusions that are difficult to see even under magnification. Effectively invisible to the eye.
- VS1 / VS2 (Very Slightly Included). Small inclusions visible under magnification but not visible to the eye in 99% of cases.
- SI1 / SI2 (Slightly Included). Inclusions visible under magnification, sometimes visible to the eye on SI2 stones depending on position.
- I1 / I2 / I3 (Included). Inclusions visible to the eye, sometimes affecting the stone's structural integrity.
Where the price jumps happen
Each grade up the scale adds a price premium, but not evenly. The biggest jumps:
- From SI1 to VS2 is significant because VS stones are guaranteed to be eye-clean.
- From VS2 to VVS2 is significant because VVS stones are essentially indistinguishable from flawless under magnification.
- From VVS1 to IF or FL is huge because these grades are rare.
A flawless 1 carat lab grown diamond can cost twice as much as a VS2 of the same shape and cut. The visible difference is zero. The only difference is what's written on the certificate.
The honest take on which clarity to buy
For an engagement ring you're going to wear, the right clarity is the lowest grade where the stone is reliably eye-clean. For most stones that's VS1 or VS2.
At VS2, you're getting a stone with inclusions that need magnification to see, no impact on brilliance or appearance, and pricing roughly 30-50% below VVS-grade stones. The savings can go toward a larger stone, a better cut, or a more elaborate setting.
If you're stretching to a stone larger than 2 carats, I'd push you to VS1 because inclusions become more visible in bigger stones. But for the typical 1 to 2 carat engagement ring, VS2 is the sweet spot.
SI1 can also be a great value if you actually see the specific stone first. Some SI1 stones are eye-clean (the inclusion is white and small, or hidden under a prong). Others have a visible black mark in the centre. Buying SI1 sight unseen is a gamble. Buying SI1 after personally checking the stone is a smart move.
SI2 and below get problematic. The inclusions are often visible to the eye, and you're not saving enough versus SI1 to justify the risk.
Things sales-driven jewellers will say
A few common pitches and how to think about them:
"You should always buy VVS or higher for an investment-grade stone." Engagement rings are not investments. The resale market for any diamond is dramatically below retail. Paying for VVS-grade clarity is paying for a certificate, not for visible quality.
"Lab grown diamonds always have higher clarity." Not true. Lab grown diamonds span the full clarity range from flawless to included, same as natural. The growing process can produce inclusions just like natural formation can.
"This SI1 looks just as good as a VS2." Sometimes true, sometimes not. It depends on the specific stone. Always check the inclusion plot on the certificate, and ideally see the stone in person under good light.
How to actually evaluate clarity
Three practical steps when shopping:
Look at the inclusion plot. Every certified diamond comes with a diagram showing where its inclusions are. Inclusions near the centre or in the top half of the stone (the crown) are more visible than ones hidden near the edges or bottom (the pavilion). A VS2 with a centre inclusion may show more than an SI1 with all inclusions tucked at the edges.
See the stone, not just the certificate. Two diamonds with identical certificates can look quite different in person. If you're buying online, ask for clear video footage of the actual stone, not stock imagery.
Match the clarity to the cut and setting. Step cuts (emerald, Asscher) show inclusions more readily than brilliant cuts. If you're choosing an emerald cut, go up a clarity grade. Halos and pavé settings hide minor inclusions effectively.
The bottom line
For most engagement rings: VS2 clarity, eye-clean, with the inclusion plot reviewed. Don't pay for VVS or flawless unless you specifically want to. The money is better spent on cut quality, which has a much larger effect on how the ring looks than clarity does.
If you want a second opinion on a stone you're considering or you want to see what different clarity grades actually look like side by side, that's part of what we do in a free consultation.