Never discount the value of fine cutting!  Everyone recognizes fine cutting.  A fine cut turns heads.  A fine cut will capture your attention and hold it.  A fine cut has pizzazz!  Poor cutting is boring, dull and lifeless.  You may not know the terms or how to describe it, but you know a fine cut when you see it.  Let us help you learn how to recognize what makes a good cut and why it is worth its weight in gold.
Gems are inherently brilliant so throwing some polished facets will enhance that.  A poor cut gem can look quite dynamic at first glance and if you don’t have a fine cut gem to compare you might be satisfied (for the moment).  We’re going to show you how to recognize cutting quality analytically so you won’t need a side be side comparison to know what you’ve got. 

Here’s the basics:

It all comes down to angles and light.  The more light coming out the top (CROWN) of the gem the more brilliance.  Light escaping out the bottom and sides means less brilliance when viewed from the top.  When light is escaping out the bottom (PAVILION) an area of no brilliance results.  This is called a WINDOW and is most often caused when a gem is cut too shallow.  When light escapes the sides brilliance is lost as well.  The optical effect is difficult to describe but you can recognize it when you see the edges seem to disappear.  This happens when a stone is cut too deep.
Polish plays a big role in brilliance.  Better polish produces a more mirrorlike finish and therefore will reflect more light.  Scratches, abrasions and chips seriously diminish the brilliance. Most pre-jewelry SCRATCHES are caused by incomplete final polish.  Many commercial cutters do not even polish the edges (GIRDLE) at all, but scratches on the table are the least desirable. Some scratches you won’t be able to see, but you might be suspicious if the gem is silky and/or always seems dirty.  ABRASIONS are micro-chips that are caused by poor handling of the gem by the cutter or dealer.  These are most common at the fringes of the TABLE (flat topmost portion of the gem) and on the ridge or point (CULET) of the pavilion.  Look for abrasions and try to avoid them at all costs.  These areas will have sharp edges that will be vulnerable to further abrading and will collect dirt quickly.
            Beware of symmetry as well.  Symmetry of shape, girdle and facet size will give the gem uniform brilliance from all angles of viewing.  Always check for the symmetry of shape.  Nothing is more annoying than a gem that is not quite round, etc.  After that, be sure to check that the table is centered.  You may not notice this immediately but believe me you’ll notice it later when the gem is set.  Symmetry of facet size is the most abused fault in gem cutting.  Check this by comparing facets on each side of the culet and each side of the girdle.  Avoid any gems that have noticeable asymmetrical facet sizes.  And finally, check the girdle thickness.  This is another factor that you may not notice until later, but a non-uniformly thick girdle will give you all kinds of trouble when prong setting.

GOOD: Proper depth, uniform and polished girdle, centered table, centered culet, symmetrical facets

BAD: Window means shallow cut, chip on girdle, and abrasions on fringes of table.