What clarity is measuring
Every diamond forms with tiny internal features and surface marks. Clarity grades how many, how large, and how visible those features are under 10x magnification. It is a graded assessment of what you see through a loupe, not through your eye.
The type of inclusion matters as much as the grade. A single small crystal off to one side is a very different thing from a feathery inclusion across the middle of the table, even at the same grade.
The scale, in plain terms
No inclusions visible under 10x magnification (FL) or no internal inclusions (IF). Beautiful and rare, and for most people, a premium you pay for a certificate line rather than for what your eye can see.
Tiny inclusions that are difficult for a trained grader to spot under 10x. Invisible to the naked eye. A safe grade if peace of mind matters more than value.
Small inclusions visible under 10x but almost always invisible face up. This is where most well-priced eye-clean stones live. Our default range for brilliant cuts.
Inclusions are easy to see under 10x. Many SI1 stones and some SI2s are still eye clean depending on the type, size, and position of the inclusion — but this range needs to be reviewed stone by stone, not bought on paper alone.
Inclusions visible to the eye and often affecting brilliance or durability. Rare in fine jewellery for good reason. We do not carry stones in this range.
What eye clean really means
A stone is eye clean if you cannot see any inclusion from about arm's length in normal lighting without magnification. That is the bar most people actually care about. Eye clean is possible from IF all the way down into SI1, and sometimes into SI2, depending on the stone.
Because the eye stops noticing well before the grading scale does, paying for higher clarity than you can see is often paying for paperwork. It also means an SI cannot be bought sight unseen — the inclusion has to be reviewed.
Shape changes how clarity reads
Brilliant cuts like round, oval, pear, and cushion break light into many sparkles, which helps hide small inclusions. Step cuts like emerald and Asscher give you a clean window into the stone, so inclusions are much easier to see.
For rounds and most fancy brilliants we're comfortable in VS2 and often SI1. For emerald and Asscher we lean toward VS2 or better, because the same inclusion that hides in a round will stand out in a hall of mirrors.
How we review clarity in the Vault
Every diamond in the Vault is reviewed in person before it is listed. We look at where the inclusion sits, how large it reads face up, and whether the stone would be considered eye clean. Anything that would not is not listed.
If a stone catches your eye, we're happy to talk you through its specific inclusions and share close-up photos before you decide.