Enhancement also refers to the faceting and polishing of a gem.
For centuries, gems have been in heat treated to improve their color. Heat treating is widely accepted because it's a continuation of a natural process and it causes a permanent improvement of the entire stone. The world of colored gems is endlessly fascinating. Since ancient times, colored stones have been thought to possess certain magical powers or the ability to endow the wearer with certain attributes. Today, gems are worn primarily for their intrinsic beauty and are chosen primarily for aesthetic reasons, The world of colored gems today offers us an almost endless choice.