Most people buying a diamond for the first time spend hours comparing carat weights and ring styles. Very few spend enough time on clarity, and that is almost always the difference between a stone that genuinely dazzles and one that quietly disappoints.
Diamond clarity is the measure of how clean a stone is on the inside and outside. It determines how light moves through the diamond, how the stone performs in real light, and how it holds up against scrutiny, both yours and everyone else's. Get it right, and you have a diamond that rewards every glance. Get it wrong, and no amount of carat weight or setting can compensate.
At Marlow's Diamonds, Birmingham, our team has spent over 70 years helping people make this decision with complete confidence. This guide gives you exactly what we share with every client who walks through our door: a clear, honest breakdown of the diamond clarity scale, what every grade truly means, and how to choose the right clarity for your stone, your shape, and your budget without overpaying for microscopic perfection that no one will ever see.
Diamond clarity refers to the absence of inclusions and blemishes. Inclusions are internal or surface-reaching characteristics, while blemishes are features on the stone's surface. The fewer and smaller these imperfections are, the higher the clarity of diamonds and the more valuable and brilliant the stone.
Clarity is graded by gemologists using 10x magnification. The GIA (Gemological Institute of America), the world's most trusted diamond authority, developed the universal diamond clarity scale that jewellers and buyers rely on globally.
This is one of the most important things to understand before buying a diamond, and most buyers never hear it.
Two diamonds can share the exact same SI1 clarity grade and yet look nothing alike in real life. One can appear perfectly clean to the naked eye. The other can have a visible dark crystal sitting directly under the table, noticeable without any magnification. Both are legitimately graded SI1. Both carry the same grade on paper. But side by side, they are worlds apart.
This is exactly why the grade alone is never enough. At Marlow's Diamonds, our experts assess every stone individually under real lighting conditions, the way you will actually wear it.
The GIA diamond clarity scale has 11 grades across 6 categories. Here is every grade clearly explained.
No inclusions or blemishes visible under 10x magnification. Extremely rare. Less than 1% of all diamonds reach this grade. The absolute pinnacle of diamond clarity quality.
No inclusions visible under 10x magnification. The stone may have blemishes, but no internal characteristics are present. Still exceptionally rare and premium priced. Both FL and IF diamonds are virtually indistinguishable to the naked eye from lower clarity grades.
Use this diamond clarity chart as your quick reference guide before buying.
|
Clarity Grade |
Category |
Visible to the Naked Eye |
Best For |
|
FL |
Flawless |
Never |
Collectors and buyers seeking maximum rarity |
|
IF |
Internally Flawless |
Never |
Premium luxury buyers |
|
VVS1 |
Very, very slightly included |
Never |
High-end engagement rings |
|
VVS2 |
Very, very slightly included |
Never |
High-end engagement rings |
|
VS1 |
Very Slightly Included |
Never |
Best overall value |
|
VS2 |
Very Slightly Included |
Rarely |
Best overall value |
|
SI1 |
Slightly Included |
Occasionally |
Budget-conscious buyers |
|
SI2 |
Slightly Included |
Sometimes |
Budget-conscious buyers |
|
I1 |
Included |
Yes |
Lower budgets only |
|
I2 |
Included |
Yes |
Not recommended |
|
I3 |
Included |
Yes |
Not recommended |
The best diamond clarity for most buyers is VS1 or VS2. Here is why.
At Marlow's Diamonds, our expert team with over 150 years of combined experience consistently recommends VS1 to VS2 for engagement rings. You get a stone that sparkles brilliantly without overpaying for microscopic perfection that no one can see.
Several factors determine where a diamond sits on the diamond clarity scale.
When a GIA gemologist grades diamond clarity, they assess five factors.
Yes, but only at the lower end of the scale. Here is the honest truth.
This is why most diamond experts, including the team at Marlow's, recommend staying at SI1 or above for the center stone of an engagement ring.
Some diamond shapes hide inclusions better than others. This is an important factor in the clarity of diamonds' charts that many buyers overlook.
| Clarity Grade | Category | Visible to the Naked Eye | Best For |
|---|---|---|---|
| FL | Flawless | Never | Collectors and buyers seeking maximum rarity |
| IF | Internally Flawless | Never | Premium luxury buyers |
| VVS1 | Very Very Slightly Included | Never | High-end engagement rings |
| VVS2 | Very Very Slightly Included | Never | High-end engagement rings |
| VS1 | Very Slightly Included | Never | Best overall value |
| VS2 | Very Slightly Included | Rarely | Best overall value |
| SI1 | Slightly Included | Occasionally | Budget-conscious buyers |
| SI2 | Slightly Included | Sometimes | Budget-conscious buyers |
| I1 | Included | Yes | Lower budgets only |
| I2 | Included | Yes | Not recommended |
| I3 | Included | Yes | Not recommended |
Every diamond at Marlow's Diamonds comes with a GIA certificate. Here is how to read the diamond clarity section.
A GIA report includes a diagram of the diamond called a clarity plot with symbols showing the exact location and type of every inclusion.
Marlow's Expert Insight: Always request the GIA certificate before purchasing any diamond. Certificates from less rigorous labs can inflate clarity grades by one or even two grades. At Marlow's, every diamond is GIA certified with no exceptions.
Choosing the best clarity for diamonds in an engagement ring depends on shape, size, and budget.
Lab grown diamonds are assessed in much the same way as natural diamonds, with experts examining their cut, finish, and internal characteristics under magnification.
The key difference today is between the grading laboratories themselves.
IGI (International Gemological Institute) continues to use the traditional diamond grading system for lab grown diamonds, providing detailed grades for:
This allows customers to compare lab grown and natural diamonds using the same recognised grading scales.
GIA (Gemological Institute of America) has introduced a simplified grading approach for laboratory-grown diamonds. Rather than issuing the full traditional colour and clarity grading scale on its standard lab-grown reports, qualifying stones are categorised into broader quality tiers such as Premium or Standard, based on their overall characteristics and finish.
Regardless of the grading laboratory, lab grown diamonds can still contain inclusions and growth characteristics, just like natural diamonds. The difference is simply how those characteristics are reported and presented on the certificate.
At Marlows Diamonds, we supply both natural and lab grown diamonds with independent certification, helping customers choose the diamond that best suits their preferences and budget.
False. FL and VS1 diamonds look identical to the naked eye. Beauty comes from cut quality and light performance, not microscopic clarity differences.
False. Many SI1 diamonds, especially round brilliants, are completely eye clean. Always view the stone in person or via HD video before buying.
False. Paying for FL or VVS clarity on a small carat stone is money spent on something no one will ever see. Value lies in the VS range for most buyers.
False. Cut is the single most important factor affecting a diamond's brilliance. A perfectly cut SI1 will outshine a poorly cut VVS2 every time.
|
Grade |
Eye Clean |
Price Level |
Best Use |
|
FL and IF |
Yes |
Very High |
Investment and heirloom pieces |
|
VVS1 and VVS2 |
Yes |
High |
Luxury engagement rings |
|
VS1 and VS2 |
Yes |
Moderate |
Best value engagement rings |
|
SI1 |
Usually |
Low to Moderate |
Budget engagement rings |
|
SI2 |
Sometimes |
Low |
Small side stones |
|
I1 to I3 |
No |
Very Low |
Not recommended for centerpieces. |
Diamond clarity is one of those details that quietly rewards those who take the time to understand it. Once you know what each grade means and what to look for in a stone, choosing a diamond becomes far less overwhelming and far more confident.
There is no single correct clarity grade for every buyer. The right choice depends on the shape you love, the size you want, and the budget you are working with. What matters most is that you feel certain in what you are choosing and why. A diamond chosen with understanding is always a diamond chosen well.
At Marlow's Diamonds, Birmingham, every diamond we offer is carefully selected, fully certified, and presented with complete transparency. Because a decision this significant deserves nothing less than absolute confidence.
VS1 or VS2 is the best diamond clarity for most buyers. These grades are completely eye-clean with no inclusions visible without magnification, yet they cost significantly less than VVS or flawless grades.
SI stands for Slightly Included. SI1 and SI2 diamonds have inclusions visible under 10x magnification. SI1 diamonds are often eye-clean, making them a popular budget-friendly choice.
Yes. VS2 is an excellent clarity grade. The inclusions are minor and virtually never visible to the naked eye. VS2 offers outstanding value and is one of the most popular grades for engagement rings.
VS1 inclusions are slightly smaller or better positioned than VS2. Both are eye-clean. The price difference between VS1 and VS2 can be 10-20%, making VS2 a smarter buy for most shoppers.
An eye-clean diamond has no inclusions visible to the naked eye when viewed from a normal viewing distance of 25 to 30 cm. Most VS1, VS2, and SI1 diamonds in round brilliant cuts are eye clean.
The GIA diamond clarity scale has 11 grades: FL, IF, VVS1, VVS2, VS1, VS2, SI1, SI2, I1, I2, and I3.
Most reputable jewellers, including Marlow's Diamonds, primarily stock VS1 through SI1 clarity diamonds for engagement rings, as these offer the best combination of quality and value.
