If you are in the market for diamond jewelry, it is important that you have at least a basic understanding of what is meant by the term diamond clarity.  The Gemological Institute of America (also known as the GIA) has developed a graduated scale through which diamonds are judged based upon their overall clarity. 

A diamond is graded through an analysis of the stone under 10x magnification.  When so magnified an examination of the characteristics of what are known as inclusions is undertaken.

At the top of the scale is what is known as a flawless diamond (FL).  Such a diamond has not flaws or inclusions whatsoever.  Next of the scale is an internally flawless diamond (IF), which is a diamond with no inclusions and only very minor blemishes on the surface.

An included diamond is one that has obvious inclusions – some that can even be seen without magnification.  The stability and durability of such a diamond is questionable (in addition to its significantly lower clarity).