What is diamond clarity?
Diamond clarity is the assessment of small imperfections on the surface and within the stone. Surface flaws are called blemishes, while internal defects are known as inclusions. In most cases, a diamond’s beauty is not affected by these in any way since most inclusions can’t be seen with the naked eye. When referring to inclusions, gemmologists often use the term “internal characteristics” instead of flaws. Internal characteristics are what give a natural diamond its character. It’s also important to note that diamonds with the fewest and smallest inclusions receive the highest clarity grades—and higher price tags to reflect that.
Remember, all diamonds are unique, not perfect. They are made underground through enormous pressure and heat. Natural inclusions and blemishes are inevitable.
Quick clarity tips
There are many misconceptions around the clarity of diamonds, including the belief that you need to buy a high clarity grade to avoid seeing imperfections. Another common falsehood is that a higher clarity grade results in more sparkle. Neither of these is true! Here are some tips to get you started on your diamond search:
- The term “eye clean” means that the diamond’s inclusions are too small to see without magnification.
- A good place to start your search and maximise your budget is with Slightly Included (SI) and Very Slightly Included (VS) grades because inclusions will not be readily noticeable without magnification.
- Diamond shape and size affect clarity. While clarity is less important than a diamond’s cut or colour, if you are buying a diamond over one carat or considering certain fancy-shaped diamonds (like an emerald or Asscher cut where flaws are more visible), you may want to spend more for a higher clarity grade.
- Diamond clarity is an important characteristic that affects a diamond’s beauty. Like all of the 4Cs, diamond clarity is an important consideration when buying a diamond. While clarity affects price, there are a number of factors that can help you decide which clarity grade is right for you.
Diamond clarity spans 6 categories with a total of 11 clarity grades
In 1953, Richard T. Liddicoat and colleagues established the Gemmological Institute of America (GIA) diamond grading system and clarity scale. The GIA diamond grading scale is divided into 6 categories and 11 diamond clarity grades.
I1, I2, I3 Included Diamonds
- I clarity diamonds have obvious inclusions that are likely to be visible and impact beauty
- Blue Nile does not sell I clarity grade loose diamonds for engagement ring designs
- Blue Nile does offer a limited selection of jewellery preset with I1 diamonds
SI1, SI2 Slightly Included (SI) Diamonds
- Inclusions are noticeable at 10x magnification
- If eye clean, SI diamonds are often the best value
- SI2 inclusions may be detectable to a keen unaided eye, especially when viewed from the side
VS1, VS2 Very Slightly Included (VS) Diamonds
- Minor inclusions ranging from difficult (VS1) to somewhat easy (VS2) to see at 10x magnification
- Great value; Blue Nile’s most popular diamond clarity
VVS1, VVS2 Very, Very Slightly Included (VVS) Diamonds
- VVS diamonds have minuscule inclusions that are difficult even for trained eyes to see under 10x magnification
- VVS clarity is rare and results in an eye clean appearance
- Characteristics are minuscule and difficult to see under 10x magnification, even to a trained eye
Internally Flawless (IF) Diamonds
- Some small surface blemishes may be visible under a microscope on IF diamonds
- IF diamonds have no inclusions within the stone, only surface characteristics set the grade
- Visually eye clean
Flawless (FL) Diamonds
- No internal or external characteristics
- Less than 1% of all diamonds are FL clarity
- A flawless diamond is incredibly rare because it’s nearly impossible to find a diamond 100% free of inclusions
Diamond Clarity Scale
Slide left and right to compare diamond clarity
Flawless (FL) Diamonds
Inclusions and blemishes aren’t visible on flawless diamonds, even under 10x magnification. Less than 1% of all diamonds are FL clarity. A flawless diamond is incredibly rare because it's nearly impossible to find a diamond 100% free of inclusions. Six percent of customers buy FL diamonds.Shop FL Diamonds
The five diamond clarity factors
Size: The larger or more noticeable a characteristic, the lower the likely clarity grade.
Number: This is the number of easily seen characteristics. Having fewer characteristics means a higher clarity grade.
Position: What is the position of any given characteristic? Is it under the table (most visible) and close to a pavilion? This position turns inclusions into reflectors, which have a bigger impact on the clarity grade.
Nature: The nature of a diamond characteristic relates to the type of inclusion and its impact on durability.
Colour and relief: Colour and relief are essentially a measure of how easily a characteristic is seen, or how much contrast there is between the characteristic and surrounding diamond.
Why SI diamonds and VS diamonds are the best value
While the extremely rare Flawless (FL) or Internally Flawless (IF) diamonds are the highest quality diamond clarity, you may want to consider a diamond that won’t break the bank. For the best value, select a diamond with inclusions that can’t be seen through the crown without magnification (also known as eye clean diamonds), like a diamond with an SI or VS clarity grade. These diamonds are much less expensive and look the same as the higher grades, visually.
Some diamond shapes require a higher clarity grade than others. Emerald and Asscher-shaped diamonds (referred to as step cut) are designed with rectangular facets that emphasise transparency and let you see farther down into the diamond, which can make inclusions more visible. For these diamond shapes, choose a clarity grade of VS1 or better to ensure that the inclusions will not be visible.
Conversely, round, princess, oval, marquise, pear, and heart-shaped diamonds may not require as high of a clarity grade. Cut with a brilliant facet pattern, which reflects light from many different angles, these shapes naturally hide many inclusions.
As diamond size increases, the size of the facets (the multiple mirror-like surfaces on the diamond) become more abundant. This can make inclusions more visible. Be sure to prioritize a higher clarity grade as the size of your diamond goes up.
The diamond clarity plot
Clarity plots are diagrams that show the location of clarity characteristics—mapping the blemishes on a diamond’s surface and the inclusions within a diamond’s interior. The inclusions are identified by a certified diamond grader using a device with 10x magnification.
You can learn more about a diamond’s characteristics (inclusions/blemishes) in the GIA Grading Report
Any characteristics that don’t get factored into the diamond’s assigned grade may still be noted on the GIA grading report or clarity plot (if there is one). As is common practice in the industry, you’ll only find a clarity plot when the diamond is over one carat.
There are many different types of diamond inclusions and blemishes
If you find the whole topic of internal and external diamond characteristics as fascinating as we do, take a deep dive and learn more about the various types of inclusions and blemishes in your diamond of interest.
Types of diamond inclusions
- Crystals or minerals
- Internal graining
Types of blemish examples
- Polish lines
- Dark or light spots
Shop Blue Nile diamonds by clarity grade
At Blue Nile, we offer the highest quality diamonds and deliver the best value for your budget. If you're shopping for a diamond ring or other diamond jewellery, we offer the following diamond clarity grades:
- FL & IF Diamonds (Rare Finds)