Cut refers to the shape of the diamond and how well it sparkles, making it the most important ciriteria to consider when buying a diamond. 

Shape

Below are some of the most common diamond shapes.  Shape is  usually the first aspect to decide on when shopping for a diamond. 

 

Round	Princess	Cushion	Emerald	Asscher	Marquise
Oval	Radiant	Pear	Heart	Trillion

 

Certain shapes sparkle more than others, with the brilliant round diamond being the most sparkly of all.    Emerald and Asscher cuts on the other hand are famous for the geometry of their cut and  not for their sparkle. 

 

 

Understanding The Cut

The science behind a properly cut diamond is to let in the right amount of llight, refract it into white and colored light, and reflect it back as a fiery sparkle.  A diamond that is cut too deep or too shallow will look dull even with exceptional color and clarity, which is why we strongly emphasize better cut over better color.   The quality of the cut depends on how well the sections of the diamonds are proportioned to one another. 

 

Here are some common terms you may run into when talking to jewelers about diamond cut.  

 

Brilliance - The total amount of white light the diamond reflects back.

 

Dispersion - Also known as "fire," dispersion is the flashes of color that result from the refraction of incoming light.  

 

Scintillation - Reflections and flashes of white light off the diamond's surface as either the diamond, the observer, or the light source move.   

 

 

Diamond Proportions

The proportions of the diamond determine the quality of its cut. The key aspects to focus on are:

 

1) Table

2) Depth

3) Polish

4) Symmetry

 

To understand this realtinoship let's first review the sections of the diamond.  

 

Sections of the Diamond

 A diamond has five major sections, as illustrated below:

 

Crown:	The top section of the diamond that also includes the table. It captures and refracts light.
Table:	The facet at the top of the diamond. See ideal table sizes below.
Girdle:	A thin band around the diamond where the crown meets the pavilion.  The girdle protects the edge of the diamond from chipping.  Look for medium  girdles and avoid extremely thick or thin.
Pavillion:	The lower section of the diamond.  It refracts light and reflects it back through the crown.
Culet:	The facet at the tip of the diamond.  The culet is not visible to the naked eye and is graded as none or small.  If the culet is too large, when you look through the diamond it will appear to have a hole at the bottom.

 

 

     

Diamond Table

The table is the flat part at the top of the crown.  It determines the amount of white light the diamond will let in.  If the table is too small, not enough light will flow into the diamond and it will diminish the sparkle.  If the table is too big, too much light will flood the diamond and it will look "glassy," so that you can see right through it.  

 

Diamond Depth

Depth simply means how deep the diamond is from top to bottom.  It determines the amount of light the diamond will reflect back, and it also impacts the size of the diamond. 

 

Deep Diamond - If a diamond is cut too deep, it will trap light and allow it to escape from the sides instead of reflecting it back through the top (crown and table).  A deep diamond will also have more of its weight concentrated at the bottom causing it to look narrow and small for its carat weight.  

 

Shallow Diamond - If a diamond is cut too shallow, light will usually pass right through the diamond and make it look "glassy," as is the case with a large table.  A shallow diamond will have more weight concentrated at the top causing it to look spready and big for its size.  

 

 

 

 

 

 

 

 

    

 

 

 

 

 

 

 

 

 

 

 The chart below provides the ideal ranges of depths and tables for the most common diamond shapes.  Top Rate Diamonds always seeks out diamonds with these ideal proportions.   

 

 

 

Diamond Cut Grades

There are several different grades used by the various labs to rate the overall quality of the cut.  The ones you will most likely encounter are as follows: 

 

Ideal/ Excellent:	Reflects nearly all light that enters the diamond and achieves maximum brilliance.
Very Good:	Reflects nearly as much light as an Ideal Cut but for a lower price.
Good:	Reflects most light that enters the diamond.
Fair:	Reflects less light than a good cut.
Poor:	These diamonds are poorly cut and tend to lose most of the light.

 

 

Diamond Polish and Symmetry

Polish refers to the finish on the exterior of the diamond.  A proper polish will leave a smooth surface clean of any marks or blurs that interfere with light going in and out.  Symmetry refers to the alignment of the facets and how well they bounce light inside the diamond to create brilliance and scintillation.  Polish and symmetry are graded as Excellent, Very Good, Good, Fair, and Poor.  Opt for diamonds with grades of Good or better for both polish and symmetry, and avoid Fair and Poor.  

 

Top Rate Diamonds Cut Recommendation: We always stress quality of the cut over any of the other Four C's.  We recommend an Ideal Cut diamond with Excellent Polish and Symmetry.  However, if you are looking for a lower-cost alternative, an Excellent cut with Very Good Polish and Symmetry is also a high quality stone.