Diamond Clarity
Clarity is the one C that customers ask about the least and misunderstand the most. Most people walk in already knowing they want a colorless stone and a good cut. Clarity is the one that gets glossed over, usually right up until they see two diamonds of the same size and color priced $2,000 apart.
What diamond clarity actually measures
Diamonds form deep in the earth under enormous heat and pressure, and almost all of them pick up small internal or external marks along the way. The internal ones are called inclusions. The external ones, on the surface, are called blemishes. Clarity is simply a measure of how few of these a diamond has, and how much they show. The Gemological Institute of America (GIA) puts it plainly: a diamond with zero inclusions or blemishes, visible under 10x magnification, is vanishingly rare. Most jewellers go their whole career without handling one.
The GIA Clarity Scale, grade by grade
GIA's scale runs 11 grades from Flawless down to Included. A trained grader looks at five things to set the grade: the size of each mark, how many there are, where they sit in the stone, what kind of mark it is, and how much it stands out against the surrounding diamond (GIA calls this last one relief).
- Flawless (FL): No inclusions or blemishes visible to a skilled grader at 10x.
- Internally Flawless (IF): No inclusions, though a trained eye can find a surface blemish at 10x.
- VVS1 / VVS2 (Very, Very Slightly Included): Inclusions so small a skilled grader has real difficulty finding them at 10x.
- VS1 / VS2 (Very Slightly Included): Minor inclusions, ranging from hard to somewhat easy for a grader to spot at 10x.
- SI1 / SI2 (Slightly Included): Inclusions a skilled grader notices without much effort at 10x.
- I1, I2, I3 (Included): Inclusions are obvious at 10x and, at the lower end, can affect how much light the stone lets through.
Most of the diamonds that actually pass through a jewellery counter fall in the VS or SI range, not the extremes. That's not a compromise. It's where the value is.
Why "eye-clean" isn't a grade on the certificate
Here's something worth knowing before you shop: "eye-clean" is not an official GIA term. You won't find it printed on a grading report. It's shorthand the trade uses to describe a stone where the inclusions don't show up to a normal person looking at the diamond face-up, at arm's length, in regular light. A VS2 is almost always eye-clean. Plenty of SI1 stones are too. Some SI2 stones are, and some aren't, which is exactly why we look at the actual diamond with a client rather than just quoting a grade off a sheet.
How the grading system came to exist
Before GIA standardized things, jewellers described clarity with terms like "loupe clean" or "piqué," phrases that meant different things depending on who was saying them and what part of the world they were in. GIA's system, developed under gemologist Richard T. Liddicoat starting in 1953, replaced that with a scale that means the same thing whether you're buying in Coquitlam or Antwerp. Say "SI1" to a jeweller in Tokyo and they know exactly what you mean, regardless of the language barrier.
What actually matters when you're choosing
In our experience on the sales floor, most people care about one thing: can I see it without trying? If the answer is no, the grade above that is usually not worth the premium. We'll put a loupe in your hand and let you look for yourself before you decide anything. A grade on paper and a diamond in front of you can tell two different stories, and only one of them matters once the ring is on your hand.
Shape matters here too. Step-cut stones like emerald and asscher cuts have wide, flat facets that act like windows into the diamond, so inclusions show up more easily. A round brilliant's smaller facets do a better job of hiding the same-size inclusion. If you're set on a step cut, it's worth going one clarity grade higher than you would for a round.
Key Takeaways
- Clarity measures inclusions (internal) and blemishes (external), graded on an 11-step GIA scale from FL to I3.
- "Eye-clean" is trade language, not a printed grade. It means the marks don't show to the naked eye at normal viewing distance.
- Most diamonds sold fall in the VS to SI range, and that's where the practical value sits.
- Step-cut shapes (emerald, asscher) show inclusions more readily than round brilliants, so consider grading up if you want a step cut.
- See the stone in person before you decide. A grade tells you where to start looking, not what to buy.
Want to compare a couple of clarity grades side by side under real light? Come into the Coquitlam showroom and we'll pull a few stones for you, or browse our diamond jewellery online to start narrowing things down first.
