Because diamonds form under tremendous heat and pressure, nearly every one possesses internal and external features called clarity characteristics. These characteristics help gemologists separate natural diamonds from synthetics and simulants, as well as identify individual gems.

Few things in nature are absolutely perfect. This is also true with diamonds. As touched on in the first part of the clarity series, diamonds have internal features called inclusions and surface irregularities called blemishes.  Together, inclusions and blemishes make up a diamond’s clarity characteristic.

Diamond clarity is one of the four quality factors (the 4Cs) that describe and determine the value of a diamond. By definition, clarity means “a gemstone’s relative freedom from inclusions and blemishes.” These two terms are locational- blemishes are found on the outside of the gem and inclusions are located on the inside. Both of these clarity characteristics can dim the brilliance of a diamond, though some are so minute that they are invisible to the naked eye.