DIAMOND CUTS

A common misconception when discussing a diamond’s cut is to confuse it with its shape. Shape refers to the outward appearance of a diamond, for example round, oval, princess or emerald cut. Cut refers to the diamonds proportions, uniformity of facets, polish and symmetry.

Cut is the only of the 4 C’s that can be controlled by man!

The Typical Round Brilliant Cut diamond contains 58 facets. Below is a chart and explanation of the various elements that make up the anatomy of a diamond.

Crown:
The upper area of the diamond above the girdle and below the table.

Crown Angle:
Should be at a 32-35 degree angle to maximize brilliance and return of light

Depth:
The height of a gemstone measured from the culet to the table.

Depth percentage:
Ratio of total depth vs. total diameter. See below illustration to see the affects of a diamond that is cut to shallow or to deep

Diameter:
The width of the diamond measured from one side of the girdle to the other.

Facets:
Smooth flat polished surfaces on a diamond. A typical Round Brilliant Cut diamond contains 58 total facets, 33 above the girdle and 25 below.

Girdle:
The widest part of the diamond, it is the outer edge that forms a band around the stone. This is where the prongs hold the mounted stone in its setting. Can be faceted or smooth.

Pavilion:
The lower pointed section of a cut diamond just below the girdle ending in the culet. It is said that this area has the most important job since it is the area at which all the light that enters the diamond is reflected back to your eye.

Pavilion Angle:
Should be at a 40-41.5 degree angle. It is very important that this angle be accurate. If off by as little as a 1/10 of a degree, much of the diamonds sparkle will not be reflected and will be “stuck” inside the pavilion or will go out the sides

Table:
The flat top and largest facet of a diamond. Should be approximately 60% of the girdle’s diameter

Table Percentage:

Ratio of table width vs. the total width of the diamond. A very important proportion as it is responsible for much of its brilliance

A diamond's cut grade is determined by several factors.

Depth percentage: Measurement of the height vs. the width
Table percentage: Measurement of the diameter of the top facet of the stone vs. the stone's average width

The Ideal Cut
To the left is an example of an “Ideal Cut” diamond. When a diamond is cut to these specifications it allows for the maximum brilliance for which the diamond is infamous for. When cut correctly, all of the light entering from any direction will be dispersed through the top of the diamond for a breathtaking display of fire and sparkle. The table for an Ideal Cut diamond should be around 53-57% of its girdle’s diameter

The Premium Cut
A premium cut diamond is similar to an ideal cut, with the proportions varying only slightly. It still produces high brilliance and return of light, and will be priced just slightly below a similar Ideal Cut diamond. The table of an Ideal Cut diamond table should be 58-61% of its girdle’s diameter.

Other Grades include "Very Good", "Good", "Fair", and "Poor".

Very Good

Usually means that the diamond cutter chose to slightly stray from the dimensions of the Ideal or Premium cut proportions in order to produce a larger stone. This type of cut will still emit a large amount of brilliance and reflect most of the light that enters it. A diamonds that is graded VG will be priced slightly below the Premium Cut diamond price.

Good

Cuts still reflect much of the light that enters it. Diamonds that are graded as “Good” are an excellent money saving choice without forgoing beauty and sparkle. A diamonds that is graded G will be prices slightly below a VG diamond.

Fair and Poor

Cuts will reflect little of the light that enters them and are produced almost strictly for maximizing the size of the diamond. These are cut to yield the maximum size stone and are priced well below an Ideal or premium cut diamonds.

Inferior Cut Diamonds

Posted in: DIAMONDS