Nearly all diamonds have physical characteristics present on or in the diamond called inclusions.   These inclusions can be clear (bubble-like), black, white, and even cloudy-like. There are flawless or internally flawless diamonds, but they are very rare and expensive. The smaller the inclusions, the higher the clarity, and the more rare and valuable the diamond becomes. The inclusions give a "fingerprint" of the diamond, and no other diamond will share the same "fingerprint".
     
 
     
 


An extremely rare 100.10-ct. D-color Internally Flawless, pear-shaped diamond was sold by Sotheby's in 1995 for $16,548,750.00 US. That's about $165,322.00 US per carat.

 

  
 
     

 

The GIA (Gemological Institute of America) clarity scale is most widely used to describe clarity of diamonds.   Listed in order from no inclusions to eye visible inclusions:

IF - Internally flawless

Vvs1 - Extremely hard to find inclusion under 10x power loupe even for experts

Vvs2 - Very, very hard to find inclusion under 10X power loupe even for experts

Vs1 -Very hard to find under 10x power loupe for inexperienced

Vs2 - Hard to find under 10X power loupe for inexperienced

Si1 - Not visible to the naked eye but somewhat easy to find under a 10x power loupe

Si2 - Generally not visible to the naked eye, easy to find under a 10x power loupe

I1 - Eye visible, somewhat easy to see with the naked eye

I2 - Eye visible, very easy to see with the naked eye

I3 - Eye visible, very easy to see with the naked eye

 

The illustration below shows how the clarity affects the value of a diamond with the color, cut, and carat weight being equal.   This graph is based on a 1 ct diamond... ideal cut, and same color comparison.

   

As you can see there is between a 5-33% difference for each step in clarity depending on which clarities are being compared.   Why the difference?   The higher the clarity the more rare it is, the more valuable it becomes.

How does clarity affect sparkle, fire and brilliance?   The more and or bigger the inclusions, the more light is absorbed and not reflected back to your eyes.   So there is less sparkle, fire, and brilliance.

So what should I buy?   Well it depends what you are buying.... an engagement ring, earrings, pendant, etc.   For engagement rings we find most people should go no lower than a SI2 clarity grade, unless it's an I1 that can be mostly covered by a claw or part of the setting.     For the average person looking at your diamond with the naked eye, it will not be possible to see the difference between a flawless diamond and a VS2.   However if you are one of those fortunate people who can afford a flawless diamond or VVS1 or VVS2 diamond than definitely do it.   They are arguably the most beautiful and it gives you bragging rights that yours is the best.  

Again I must emphasize the cut.   I would rather get a diamond of SI1 clarity with an Ideal/very good cut than a Flawless diamond with a medium cut.

 

Our 2 cents worth:

A word of wisdom: an I2 is not for an engagement ring guys. I've been with a gemologist and seen this scenario too many times from people who bought their ring at a chain store.   After a couple of months, the couple comes in with their engagement ring and she's crying and says, "there is a piece of dirt or something in my diamond and it won't come off.   I only noticed shortly after I cleaned my ring."   The gemologist looks at it. She says, "the piece of dirt shows up when she tilts it a certain way in certain light and it bothers her."   Then the gemologist looks at the appraisal they were given by the jewelry store and says, "your stone is an I2 (eye visible) and you must have not seen it in the special sparkling halogen lights jewelry stores use" and points out that an I2 is low on the clarity scale. Had this guy bought from Her Dream Diamond Inc., he would not have been embarrassed in front of his girlfriend.   By the way it's no accident that jewelry stores use those bright halogen lights.   Those lights make it difficult for inclusions to be seen and hide the yellowish tint in lower color diamonds.   When we meet with our customers we give them a high quality 10x power loupe to see the diamond they are about to buy and point out all the inclusions so there are no embarrassing surprises.   And if you are buying over the Internet we can take exceptional photos of our in-stock diamonds and point out the inclusions for you at your request.

For earrings and pendants we recommend going no lower than I1 clarity.    The diamond will lose too much brilliance and looks more like a quartz stone rather than a diamond.