The Blue Heart diamond is a 30.62-carat, heart-shaped, blue diamond. The color grade of the diamond is not known, but the color is variously referred to as dark blue, deep blue, steel blue etc. However, if one goes by the appearances of the diamond, it may qualify as a fancy intense blue or fancy vivid blue, according to the GIA color grading system.
The "Blue Heart" diamond is the 5th largest blue diamond in the world according to the list of known famous blue diamonds. See table below.