What Clarity Grades
Actually Look Like
Every certificate lists a clarity grade. Almost nobody knows what the letters mean for the stone in front of them. This page explains what the scale measures, then puts a jeweller's loupe in your hand so you can see what each grade looks like at 10x, and what it looks like from across a table. The scale, and everything on this page, applies to natural and lab-grown diamonds alike; where the money differs between the two, it says so.
Clarity is a measure of what is inside the stone. Nearly every natural diamond grew around tiny crystals, fractures and specks of other minerals over a billion years. The grade says how many there are, how big, how dark, and where they sit.
A grader looks at the stone face-up under a 10x loupe and places it on an eleven-step scale that runs from Flawless to Included 3. The thing most buyers miss is that the top half of that scale is invisible without the loupe. A VVS1 and a VS2 look identical on a hand. The price does not.
So the useful question is not "what is the best clarity?" It is "at what point on the scale would I actually see something?" That line is called eye-clean, and it is the line the tool below is built to show you.
One thing to settle first: this applies to lab-grown diamonds exactly as it does to natural ones. They are graded on the same scale by the same labs, and they have inclusions too, often small metallic specks or dark pinpoints left by the growing process. The difference is commercial. Most lab-grown stones are sold at VS or better because growing clean is cheap, so the price gaps between grades are a fraction of what they are in natural stones.
Grades you can explore in the loupe below. The gold line marks where a stone stays eye-clean in practice; from SI1 downward it depends on the individual stone.
- 1Pick a grade
- 2Move the loupe over the stone
- 3Untick the loupe to see it by eye
The four things you will find inside a diamond
Certificates plot inclusions with symbols and names that mean nothing until someone shows you. These are the four that matter, drawn the way they appear in the loupe above.
Crystal
A small mineral trapped as the diamond grew, often another diamond. Clear ones are harmless. Dark ones under the table are what push a stone from eye-clean to not, so always ask where it sits.
Feather
A tiny fracture. Seen edge-on it is a white line; face-on it can vanish. Mostly cosmetic, unless it reaches the girdle, where setting pressure can extend it. A jeweller should flag that.
Cloud
A cluster of pinpoints too small to plot one by one. A small cloud is nothing. A large one can make part of the stone look milky, which no grade letter will warn you about. Look at the stone.
Pinpoint
A single white speck, usually the only thing separating a VVS from an IF. You will never see it without a loupe, and you will struggle with one. Not worth a penny of premium on its own.
Eye-clean is the grade that matters
Nobody will ever look at the ring through a loupe again after you buy it. It will be seen on a hand, at arm's length, in daylight and restaurant light. If the inclusion cannot be found at 30cm, the stone is eye-clean, and from that point upward the clarity grade is a line on a certificate rather than something in the room.
That is why experienced buyers in Hatton Garden tend to shop VS2 to SI1 and spend the difference on cut, which you can see from across a table, or on carat weight. The trick with SI1 is that it has to be the right SI1: a white feather off to the side rather than a dark crystal dead centre. This is the one grade where seeing the actual stone, or at least a proper video of it, earns its keep.
Where the price steps are
Indicative for a 1 carat natural round, same colour and cut, against VS1. Lab-grown stones sit on the same ladder but the rungs are much closer together in pounds: the order of the advice holds, the savings are smaller. Real spreads move with the market and bigger stones widen the gaps.
- FL / IF+30 to 40%
- VVS1 / VVS2+15 to 20%
- VS1baseline
- VS2about 10% less
- SI120 to 25% less
- SI230 to 35% less
- I145% less or more
Three things to ask for
The loupe, in your own hand
Any good jeweller will hand you a 10x loupe without being asked. Hold it close to your eye, bring the stone up to it, and look through the table first.
The plot on the certificate
GIA and IGI reports include a diagram showing where each inclusion sits. A VS2 with its crystal under the crown facets is a better buy than one with it dead centre under the table.
Face-up, at arm's length
Put the loupe down. Hold the stone at 30cm in normal light. If you cannot find the inclusion, it is eye-clean, and that is the grade that matters when it is on a hand.