Flawless

• A diamond that is graded as flawless is without any scratches, blemishes or other types of inclusions under 10x magnification. According to the Gemological Institute of America, a diamond without any scratches or marks is rare. If a flawless diamond is found, expect a hefty price tag. Diamonds are priced based on rarity, and a perfect diamond is very rare.
  
  

Internally Flawless

• A diamond with a clarity grade of internally flawless means that the diamond doesn't have any inclusions, but does have blemishes, typically found under 10x magnification. A blemish may mean nicks, scratches or pits in the stone. In most cases, a jeweler can polish a diamond to remove small nicks; however, over-polishing may further damage and devalue the diamond.
  
  

Very, Very Slightly Included

• Very, very slightly included means it is difficult to find inclusions in the diamond using 10x magnification. An inclusion may mean naturally occurring and/or man-made imperfections, such as carbon or clouds, may be found inside the diamond. Depending on the level of clarity, a diamond may receive a grade of VVS1 or VVS2.
  
  

Very Slightly Included

• A diamond with a clarity grade of very slightly included means inclusions are evident when the diamond is placed under 10x magnification, though the internal and/or external blemishes are considered minor. Depending on the level of clarity, a diamond may receive a grade of VS1 or VS2. According to the Gemological Institute of America, the majority of diamonds fall within the very slightly included and slightly included grade scale.
  
  

Slightly Included

• Slightly included diamonds contain inclusions and/or blemishes that are somewhat noticeable when placed under 10x magnification. These internal and/or external flaws may be slightly worse than minor, but do not interfere with the brilliance or transparency of the diamond. Depending on the level of clarity, a diamond may receive a grade of SI1 or SI2.
  
  

Included

• Located at the bottom of the GIA grading scale, a diamond that comes with an included grade contains blemishes and/or inclusions that are obviously apparent when placed under 10x magnification. These internal and/or external flaws are intense enough to alter the brilliance and transparency of the diamond. Depending on the level of blemishes, a diamond may receive a grade of I1, I2 or 13.