Clarity grades how free a diamond is of internal inclusions and surface blemishes. A gemmologist examines each stone under ten-times magnification and assigns a grade from Flawless to Included. A higher grade means fewer and smaller features, but on its own it does not make a diamond more beautiful, because much of what a grade describes is invisible to the unaided eye. Clarity is best read alongside cut, colour and carat, not chased in isolation.
The clarity scale
GIA and IGI use the same eleven grades, grouped into six bands.
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FL, Flawless: no inclusions or blemishes at ten-times magnification. Extremely rare.
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IF, Internally Flawless: no internal inclusions; only minor surface blemishes.
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VVS1 and VVS2, Very Very Slightly Included: inclusions so small they are difficult even for a skilled grader to find.
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VS1 and VS2, Very Slightly Included: minor inclusions, visible under magnification but not to the eye.
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SI1 and SI2, Slightly Included: noticeable under magnification, and in some SI2 stones faintly visible to the eye.
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I1, I2 and I3, Included: obvious inclusions that can affect transparency or, in lower grades, durability.
Within each band the lower number is cleaner, so VS1 sits above VS2 and SI1 above SI2.
The sweet spot
For most commissions the best value lies between VS and a clean SI. A well-chosen stone here is usually eye-clean: no inclusion is visible to normal vision at arm’s length, face-up, without magnification. In the setting it looks every bit as clear as a flawless stone, yet costs considerably less. Flawless and internally flawless grades carry a steep premium for a difference no one sees once the ring is worn. Eye-clean, not the grade alone, is the measure that matters.
How inclusions affect the look by shape
Shape changes how forgiving a diamond is. Brilliant cuts, such as round, oval, cushion and pear, have many small facets that scatter light and conceal inclusions, so a clean SI often performs well. Step cuts, such as emerald and Asscher, use long open facets and a large flat table that acts like a window into the stone, so they reveal inclusions far more readily and we tend to recommend VS or better. Position counts too: an inclusion near the edge can hide under a claw, while one beneath the table is harder to mask. Our diamond shapes guide covers how each shape behaves.
How we guide your choice at consultation
We start with your shape, budget and how the ring will be worn, then match a clarity grade to those facts. We read the certificate and its plotted inclusion map with you, and talk through comparable certified options, sourced to your brief, so you can weigh any difference with us. Every centre stone comes with GIA or IGI certification, in natural or lab-grown diamond, and the finished ring is hallmarked at the London Assay Office, included.
Is a flawless diamond worth the extra cost?
Rarely, for jewellery worn daily. An eye-clean VS or SI looks identical in a ring and leaves more of your budget for cut and size, which you do see.
Will anyone notice inclusions in an SI diamond?
In a well-selected, eye-clean SI set in a brilliant cut, no. We check every stone face-up before recommending it.
Does clarity affect a diamond’s sparkle?
Cut drives sparkle far more than clarity. Only the larger inclusions of the lower Included grades block enough light to dull a stone.
For a clear, no-obligation view on the right clarity for your design, book a free consultation. We reply within four working hours, Monday to Friday. Read more on the 4Cs of diamonds and diamond colour, or arrange your consultation.
