Whether you’re choosing a diamond that will be the centrepiece of your mangalsutra or a little pendant to add some extra sparkle to your daily style, understanding diamond clarity will help you make a more informed and lasting investment.
And it’s more straightforward than you might think. Here, we’ll explain it all, from the diamond clarity scale to inclusions, blemishes and the rest of the 4Cs too.
How clarity and inclusions affect diamond grading
You might already know that natural diamonds are graded based on the 4Cs: cut, colour, clarity and carat weight. These four factors work together to determine a diamond’s overall appeal and financial value. And while all of them matter, clarity is often emphasised.
In simple terms, it means how free a diamond is from internal birthmarks (known as inclusions) and external markings (known as blemishes). These can be anything from tiny crystals trapped inside the stone to little feather-like lines or minute dots that are often impossible to spot with the naked eye.
How the diamond clarity scale works
Currently, only one institute (the International Gemological Institute) continues to grade natural diamonds and LGDs in the same way using the diamond clarity scale. HRD Antwerp recently announced that it will stop grading loose lab-grown diamonds in 2026. It will continue to research the stones and will still issue reports for jewellery set with lab-grown stones but is instead turning its focus to natural diamonds.
The Gemological Institute of America (GIA) has introduced a more streamlined assessment method of grading man-made diamonds. Given that most lab-grown stones occupy a narrow range of quality characteristics, they are now classified as either ‘standard’ or ‘premium’ based on their quality and craftsmanship. The diamond clarity in these cases is either very good or excellent, and anything considered below this standard is not graded at all.
To be classified as ‘premium’, a lab-grown stone must meet all of the following criteria: VVS clarity or higher; D colour; excellent polish and symmetry; and an excellent cut grade for round brilliants. The LGDs that meet any combination of the ‘premium’ criteria, and another minimum criterion set will be classified as ‘standard.’
In lab-grown stones, clarity assessments focus largely on manufacturing-related characteristics, such as metallic inclusions from growth catalysts, growth patterns or other structural features resulting from the controlled production process. These differ from the natural inclusions found in mined diamonds, which are formed over billions of years under geological pressure and often reflect the stone’s unique origin.
It’s also worth noting that while many lab-grown stones achieve high clarity due to controlled growth conditions, natural diamonds often display more varied and unique clarity characteristics, which is part of what makes each one distinct.
For those gradings using the diamond clarity scale, a universal system is adopted to help determine how ‘clean’ a natural diamond appears internally and externally. This scale currently ranges from:
- FL (Flawless): no inclusions or blemishes are visible under 10x magnification
- IF (Internally Flawless): no inclusions visible, only minor surface blemishes
- VVS1 & VVS2 (Very Very Slightly Included): inclusions are extremely difficult to detect, even under magnification
- VS1 & VS2 (Very Slightly Included): inclusions are minor and difficult to see with the naked eye
- SI1 & SI2 (Slightly Included): inclusions are noticeable under magnification and may be visible without it
- I1, I2 & I3 (Included): inclusions are usually obvious and may affect the diamond’s transparency and brilliance1
In most fine jewellery, especially the smaller solitaire sizes that are popular today (around 0.25–0.30 ct), VS clarity and above typically appears beautifully clean, making them highly sought-after choices.
What’s important to note is that these categories aren’t about good versus bad per se; they’re simply tools to help us understand a diamond’s internal makeup. And although a diamond clarity chart or scale can be helpful, it’s worth remembering that most inclusions are microscopic. You’d need a jeweller’s loupe (a specialist magnifying glass) to spot them, and many inclusions have no impact on sparkle.
That said, if you’re investing in a key piece like a solitaire ring or everyday studs, opting for VS clarity or higher ensures the stone looks clean in all types of lighting.
How clarity and inclusions tell the story of a natural diamond
Natural diamonds are formed under intense pressure and heat deep beneath the Earth’s surface. As they make their epic journey towards the surface, they are likely to pick up a few souvenirs along the way. Diamond inclusions are the geological equivalent of freckles, gentle little marks shaped by time and nature that make each diamond unique.
Inclusions in natural diamonds can be anything from tiny fractures and marks created in the intense formation process, to other minerals built up within the stone. They tell us the diamond is natural, formed over time and completely one-of-a-kind.
It’s important to think of inclusions as birthmarks of authenticity instead of imperfections. If your diamond has a feather or a pinpoint, that’s an assurance of its natural origin. They are beautiful reminders of your diamond’s identity and fascinating backstory.
In fact, on rare occasions, inclusions in natural diamonds aren’t just tiny fractures or pinpoints, they can be minute crystals of other minerals like garnet or peridot, trapped deep in Earth’s mantle and frozen forever in stone. Such rare gem-within-a-gem instances offer not just sparkle, but geological legacy — a little piece of Earth’s deep history held in your jewellery.
How lab-grown diamonds differ in clarity and character
Lab-grown stones are created in factory environments using HPHT (High Pressure High Temperature) or CVD (Chemical Vapour Deposition) methods. These processes aim to mimic Earth’s conditions in a much more controlled environment, which results in diamonds with typically fewer inclusions that can be made in a matter of weeks2.
Fewer inclusions don’t mean none at all, though. LGDs can still have man-made inclusions that are often metallic or synthetic growth-related33. In many cases, these imperfections are minimised or strategically placed. The result? Diamonds that look hyper-clean, and almost pristine. Much like a filtered Instagram image — pretty but often missing authenticity, a sense of character or personality.
So, if heritage, authenticity and emotional resonance are of high up on your checklist, natural diamonds are your ideal match.
Why brilliance and cut matter just as much as clarity
The diamond clarity grading system exists to help standardise evaluation, not to tell you how to feel about a certain diamond. There’s something incredibly beautiful and alluring about a gemstone that’s weathered with time and pressure while still managing to dazzle.
Additionally, a diamond with slightly more birthmarks, but an incredible cut will sparkle much more than a technically flawless gem with a mediocre cut. That’s because the brilliance and light performance of a diamond matter more than clarity.
For instance, a pair of diamond bangles might technically sit lower on the diamond clarity scale than a solitaire pendant, yet appear brighter. That’s because bangles often feature many well-cut smaller diamonds and when dozens of brilliantly cut stones catch the light together, they create an intense, continuous sparkle. In pieces with smaller diamonds, clarity matters far less than cut and overall light performance.
Many diamonds that fall somewhere in the VS (Very Slightly Included) or SI (Slightly Included) range are what jewellers call ‘eye clean’, too. This means that any birthmarks are invisible to the naked eye.
How to choose the right clarity for your diamond jewellery
Firstly, seeing a diamond before you buy it is a must. Clarity reports are great, but they don’t always reflect the magic and emotional resonance of a natural diamond like when it is in front of you.
Secondly, consider what resonates with you. It’s about your personal values and tastes, not prescriptive rules or trends. Diamonds are beautiful and rare, but each one is also unique, much like you are. Being given a natural diamond with birthmarks could be compared to receiving a handwritten letter over a text or email — it’s more personal and one-of-a-kind, thanks to its unique nature, formed over millions of years below the Earth’s surface.
Either way, choosing a natural diamond isn’t just about relying on the diamond clarity scale, it’s about considering the full story the gemstone tells you and deciding which qualities matter most to you.
Sources:
- 4cs.gia.edu/en-us/diamond-clarity ↩︎
- Evediamonds.com/blog/do-lab-grown-diamonds-have-flaws-discover-what-you-need-to-know#:~:text=Lab%20grown%20diamonds%20tend%20to%20have%20fewer%20and%20less%20severe,particularly%20in%20lower%20clarity%20grades ↩︎
- Iradiam.com/blog/do-lab-grown-diamonds-have-fewer-inclusions-than-mined-diamonds ↩︎
