TL;DR: the diamond clarity scale describes how many internal marks and surface blemishes a diamond has, from Flawless at the top to Included at the bottom, and most of the differences between the middle grades cannot be seen by eye. For most engagement rings, an eye clean stone in a good cut is more important than the highest grade. We describe each stone honestly. Pieces start from £600.
What clarity means
Clarity describes the internal features, called inclusions, and surface features, called blemishes, in a diamond. A grader looks at the stone under ten times magnification and considers the size, number, position and visibility of these features. It is one of the four Cs, with cut, colour and carat weight.
The scale
- FL, Flawless: no features visible under magnification.
- IF, Internally Flawless: no inclusions visible, only minor surface features.
- VVS1 and VVS2, Very Very Slightly Included: very difficult to see under magnification.
- VS1 and VS2, Very Slightly Included: minor features, difficult to see to a trained grader.
- SI1 and SI2, Slightly Included: noticeable under magnification, and sometimes visible to the eye.
- I1, I2 and I3, Included: features that are visible to the eye and may affect brilliance or durability.
What you can see
In the higher grades, you cannot see the differences without magnification. In the middle grades, many stones look clean to the naked eye. At the lower end, inclusions can be visible and can sometimes affect the strength of a stone. The size and position of an inclusion matters as much as the grade: a feature near the edge may be hidden by a claw, while one in the centre may be easier to see.
Eye clean
A stone is eye clean if you cannot see inclusions without magnification at a normal viewing distance. Two stones with the same grade can differ in whether they are eye clean, because grades are ranges. That is why we encourage you to look at the actual stone, in a video if possible, and not to rely on the grade alone.
Balancing clarity with the rest
Paying for a higher clarity grade than you can see is one place where people spend more than they need to. Many buyers prefer to put the money into cut, which affects how lively a stone looks, or into size. A shape with large facets, such as an emerald cut, shows inclusions more easily than a brilliant cut, so clarity matters more there.
Lab grown stones
Lab grown diamonds are graded on the same scale as natural ones. Clarity grading applies in the same way. We describe each stone plainly as natural or lab grown.
Reading a report
A grading report lists the clarity grade and often a plot of the main features. Check that the details match the stone and your invoice. Our guide to reading your invoice and certificate explains what to look for.
Working with us
Our guide to how written approval works shows where the stone and design are confirmed before anything is made.
We talk through suitable stones by video consultation and message. We make nothing until you approve the design in writing. Standard making time is 5 to 6 weeks, varying with your location and how busy we are.
Frequently asked questions
What clarity grade should I choose?
Many people choose a grade that is eye clean. The right grade depends on the stone and shape.
Can I see inclusions with the naked eye?
In lower grades, sometimes. In higher grades, generally not.
Is a flawless diamond worth it?
That is a personal choice, since the difference from lower grades is usually invisible.
Does clarity affect strength?
Large or badly placed inclusions can affect durability, which is why we check the stone.