From D to Z? - Heart In Diamond

As you may already know, not all diamonds are crystal clear.  Chemical imperfections and structural flaws can create diamonds of virtually any color of the rainbow.  In some cases, these colors are brilliant and beautiful--and actually increase the value of a diamond. The slight discoloration of an otherwise translucent diamond, however, is considered a negative.  That’s why “colorless” diamonds are usually graded based upon a standardized scale running from D (perfectly clear)  to Z (strong yellowish tint.)  This seemingly odd arrangement actually has a very logical origin.  No one is completely objective, and jewelers are no exception.  Because most of us have been dealing with grading that starts at A for our whole lives, it was decided that people could be more impartial if they graded diamonds on a fresh scale that did not’ carry any previous associations.  Thus the “D to Z” grading scale was born.