Diamond Clarity Guide: What Actually Matters

Clarity is the most misunderstood of the four grading factors, largely because the scale is built around what a gemologist can see under 10x magnification, not what an actual person can see by eye whilst on the hand. The result is many buyers pay a premium for clarity grades that make no visible difference, while the grade that would have looked identical to the eye sits considerably cheaper on the shelf next to it.

This guide explains the clarity scale properly and, more usefully, tells you where the real cut-off is between “worth paying for” and “invisible either way.”

This is part of our full Engagement Ring Guide. It pairs directly with our Colour Guide and Diamond Shape Guide, since all three interact.

What Clarity Actually Measures

Clarity grades the presence of inclusions (internal characteristics) and blemishes (surface characteristics) formed naturally as the diamond crystallised. Every diamond has some, flawless stones are exceptionally rare and priced accordingly and the scale runs from Flawless down to heavily included:

•FL / IF (Flawless / Internally Flawless): No inclusions visible under 10x magnification. Exceptionally rare, and priced well beyond what the visual difference justifies for almost any buyer.

•VVS1 / VVS2 (Very, Very Slightly Included): Inclusions so minor that even a trained grader needs magnification and time to find them. Effectively invisible to the naked eye in any setting.

•VS1 / VS2 (Very Slightly Included): Minor inclusions, typically not visible without magnification. This is where most inclusions genuinely stop being a practical concern for buyers.

•SI1 / SI2 (Slightly Included): Inclusions that may be visible under magnification and, in some individual stones, faintly visible to the naked eye — this is where it starts to depend on the specific stone rather than the grade alone.

•I1 / I2 / I3 (Included): Inclusions visible to the naked eye, sometimes affecting brilliance as well as appearance.

Where the Real Value Sits

VS1–VS2 is the sweet spot for almost every buyer. At this grade, inclusions are essentially never visible without magnification, regardless of shape or lighting and the price is noticeably lower than VVS or Flawless for a difference nobody looking at the finished ring will ever detect.

SI1 is where it gets genuinely useful and genuinely stone-specific. A well-selected SI1 stone can be entirely “eye-clean” (no visible inclusions without magnification) and priced meaningfully below VS2.

The catch is that SI1 is a wider grade than VS, meaning quality varies more between individual stones, some SI1 diamonds are eye-clean, some aren’t. This is the one grade on the scale where it’s worth actually seeing the specific stone, or clear video of it, rather than buying on the certificate alone.

SI2 and below is where shape starts to matter more than the grade itself, covered below.

Why Shape Changes the Answer

Clarity doesn’t behave the same way across every diamond shape, because different cuts hide or expose inclusions differently.

Round brilliants are the most forgiving. Their faceting pattern scatters light in a way that disguises inclusions unusually well, which is why a round brilliant can often go a full grade lower than other shapes and still look clean.

Step-cut shapes (emerald, Asscher) are the least forgiving, because these cuts have large, open facets rather than a brilliant faceting pattern, inclusions are considerably easier to spot. If you’ve chosen an emerald or Asscher cut, it’s worth holding to VS2 or above rather than dropping to SI, since the same inclusion that would be invisible in a round brilliant can be clearly visible in a step cut.

Cushion, oval, and pear sit in the middle, more forgiving than step cuts, less forgiving than round, and generally safe at VS2 or a well-selected SI1.

What’s Not Worth Paying For

Flawless and Internally Flawless grades carry a significant price premium for a difference that’s invisible without a jeweller’s loupe and a trained eye, money spent here buys certainty on a certificate, not anything visible on the hand. For almost every buyer, that budget is far better spent on cut quality, colour grade suited to the metal or carat weight, all of which have a real, visible effect on how the finished ring looks.

A Simple Way to Approach It

Start at VS2 as a safe, essentially invisible baseline for any shape. If your stone is a round brilliant, it’s reasonable to consider SI1 and put the saving towards size or setting. If your stone is a step cut, stay at VS2 or above rather than dropping down. Wherever you land, ask to see the specific stone (photos or video, not just the certificate) once you’re near the SI range, since this is the point where individual stones genuinely vary.

Continue Reading

•Engagement Ring Guide:  the full pillar guide covering shape, setting and metal

•Diamond Colour Guide

•Diamond Shape Guide

•Book a Consultation: talk through clarity, shape, and budget together, before you buy