CLARITY OF DIAMONDS

Author: Marta Kłosowska – diamond expert

 

 

Introduction – what is diamond clarity?

 

My name is Marta, and for years I have been involved in diamonds and selecting the perfect stones for jewelry.

Diamond clarity is one of the key parameters determining a diamond's quality and value. Every diamond is a natural mineral formed under extreme conditions, which is why it almost always contains inclusions and minor blemishes.

Clarity is determined based on the number, size, and characteristic internal and external features.

These small inclusions and imperfections determine which clarity grade a particular brilliant will fall into.

Diamond clarity and the 4C's principle

 

Diamond clarity is one of the elements of the 4C's principle, alongside parameters such as:

• diamond cut
• color
• carat (i.e., the weight of diamonds as a unit of measurement)

It is the combination of these characteristics that affects the final value of the diamond and its appearance in diamond jewelry.

Well-chosen stone clarity has a significant impact on the diamond's brilliance.

Diamond clarity scale (GIA)

 

The most recognized diamond clarity classification was developed by the Gemological Institute of America (GIA).

This system is used exclusively for diamonds in renowned laboratories (e.g., HRD or other gemological laboratories).

The evaluation is carried out at 10x magnification, using an aplanatic and achromatic loupe.

A gemologist assesses clarity using a loupe and magnification, analyzing inclusions and blemishes.

Diamond clarity grades – full scale

 

Below you will find all diamond clarity grades and their brief explanation.

Highest clarity grades

 

FL (Flawless) – flawless

A diamond completely free of characteristic internal and external features.

Invisible to the naked eye and even under a 10x loupe.

IF (Internally Flawless) – internally flawless

No internal features, minimal surface defects possible.

A practically perfect diamond – extremely rare.

Very high clarity

 

VVS1 / VVS2 (Very Very Slightly Included)

(Very Small Inclusions)

Very small inclusions, invisible to the naked eye and difficult to spot even with a loupe.

VVS1 and VVS2 subgrades are among the most valued groups.

High clarity

 

VS1 / VS2 (Very Slightly Included)

Small inclusions visible at 10x magnification, but not visible to the unaided eye.

VS1 and VS2 subgrades offer an ideal balance between price and diamond quality.

Medium clarity

 

SI1 / SI2 (Slightly Included)

Inclusions visible with a loupe, sometimes visible to the naked eye.

SI1 and SI2 subgrades (i.e., SI clarity grades) are a popular choice for jewelry, e.g., engagement rings.

SI1 and SI2 often offer a very good price-to-quality ratio.

Lower clarity grades

 

I1 / I2 / I3 (Included)

Numerous internal features and impurities visible to the naked eye.

I1, I2, I3 grades (formerly P1, P2, P3) indicate lower stone quality.

They can affect durability and brilliance.

Are inclusions a problem?

 

It's worth noting that most diamonds have inclusions.

However, not every defect means something negative – many are small impurities that are invisible to the naked eye.

Therefore, the clarity of brilliants should be assessed in the context of the entire stone.

Why do two diamonds of the same clarity look different?

 

A diamond's appearance is influenced by more than just the clarity grade.

Important factors are:

• cut
• color
• stone weight (carat)
• inclusion placement

Even with the same grade (e.g., VS1 and VS2), the visual effect can be completely different.

What diamond clarity to choose?

 

From my experience:

• VS1 and VS2 – best choice for most customers
• SI1 – good compromise of price and quality
• VVS1 and VVS2 – for those seeking perfection
• FL / IF – mainly for investment

Most important: the diamond should look clean to the unaided eye.

How to use this knowledge?

 

This page presents different clarity grades and basic diamond clarity grades.

Each grade can be expanded on a separate subpage to accurately assess the clarity of a specific stone.

This makes it easier to match the perfect diamond to your jewelry.

Summary

 

Diamond clarity is one of the most important parameters affecting its quality and value.

However:

the highest clarity is not always the best choice.

The most important factor is the visual effect, meaning how the cut diamond appears to the naked eye.

 

Additional expert tips

 

Finally, it's worth remembering one key thing: every diamond is a unique mineral, and its clarity is just one of the elements affecting the final quality of the diamond.

Stone clarity is assessed according to strict rules developed by the Gemological Institute of America (GIA). In practice, this means analyzing inclusions, blemishes, and characteristic internal and external features at 10x magnification, using an aplanatic and achromatic loupe.

However, for the client, the most important thing is how the diamond looks to the unaided eye.

This is why many diamonds in grades such as VS1, VS2, VVS, and SI1 and SI2 appear perfect, even though they may have small inclusions or minor imperfections.

In the context of the entire 4C's principle (i.e., parameters such as cut, color, and carat (diamond weight as a unit of measurement)), the clarity of brilliants should be chosen consciously—for specific jewelry, such as an engagement ring or other jewelry items.

It is the appropriate combination of these features that determines the diamond's brilliance and how intensely it reflects light.

Remember:

• not every inclusion is a defect,
• many imperfections are invisible to the naked eye,
• and a well-chosen brilliant can look perfect despite a lower clarity grade.

Therefore, instead of focusing solely on tables and diamond clarity classifications, it is worth looking broader—at the real visual effect and the value and quality of the entire stone.

This approach is used by professionals in laboratories (e.g., HRD) and experienced experts in the precious stone market.