Diamond Educationd - Diamond Cut

When a diamond is cut to proper proportions and is finished well, light refracts into the diamond, is reflected from one facet to another and then returns through the top of the gem resulting in a display of brilliance (white light), dispersion (rainbow-colored light) and scintillation (sparkling when the diamond moves), and luster (bright reflections from the surface). Proper cutting is the key to a diamond's beauty and value.

Most diamond shapes are cut with 58 facets, or separate flat surfaces, according to mathematical formulas. Using symmetry, the cutter aligns these facets at precise angles in relation to each other to maximize the reflection and refraction of light.

The proportions are calculated in angles & percentages that show how well the diamond refracts and reflects light. They will help you understand the range of well-cut diamonds offered by Mansfield Designs,.

When purchasing a diamond, you also may want to consider the grading assigned to the girdle, culet, and polish.

Analyzing Cut
To understand the sub-categories for well-cut diamonds, think of a pyramid with "Ideal" at the top. This narrow range is reserved for the most brilliant, rare and valuable diamonds. The "Excellent" range includes beautiful diamonds that return almost as much light. "Very Good" represents the balance between precise proportions and price considerations.

In many cases, the visual differences may be indiscernible to the naked eye. However, we want to provide you with all the information that you need to select the diamond that is right for you. Refer to the chart below to see the depth and table percentages for each shape, according to "Ideal, Excellent and Very Good" sub-categories. The graph for round diamonds is representative of the graphs for all the other shapes. Keep in mind that the lowest score becomes the overall cut grade. For example, if the table percentage falls within Ideal, but the depth percentage is in the Very Good range, then the diamond is classified as Very Good. The table takes into account the varying proportions for different shapes.

CROWN:   Balance, Brilliance, Dispersion, and Scintillation
GIRDLE:    Provide a Setting Edge for the gem
PAVILION:    Reflect light back up through the crown
CULET:    Prevent Chipping at the tip

The Path Of Light In 3 Differently Proportioned Diamonds

The girdle usually has a frosted appearance. Many diamonds are also finished with a fully polished or even a faceted girdle, depending on the cutter's preference. This will not affect the diamond's value.

Pavilion: The area of the diamond below the girdle.

Table: The largest facet on any diamond, place and polished on the top of the gem.

TOTAL DEPTH

Round Diamonds
The proportion dimension calculated by dividing the depth in millimeters by the average girdle diameter.

Fancy-Shaped Diamonds.
The proportion dimension calculated by dividing the depth in millimeters by the diamond's width.

Culet
The culet is the bottom point of the diamond. In many cases, this point actually has a very small facet. The culet is graded according to the presence or size of this facet: None or Pointed, Very Small, Small, Medium, Slightly Large, Large, Very Large and Extremely Large. The more desirable culets are graded from none to small.

Polish
This characteristic refers to the finishing or final polishing of the facets, or flat surfaces. Each facet should be carefully fashioned by the diamond cutter to shine and be free from polishing imperfections that can dull the diamond. The polish of a diamond is generally defined as: Poor, Fair, Good, Very Good, or Excellent. When purchasing a diamond, generally the rarer color and clarity diamonds are also well polished.

Contrary to common belief, diamonds are ground and polished, not chipped away, until they reach their final form.

Symmetry
This characteristic refers to the alignment and positioning of the facets, or flat surfaces. The alignment should be sharp and precise and in proper proportion to the other facets to allow light to be reflected. Improperly joined facets can made a diamond appear uneven. The symmetry of a diamond is generally defined as: Poor, Fair, Good, Very Good, or Excellent. Again rarer diamonds generally have better symmetry.

FANCY SHAPES AND VALUE
All factors being equal, fancy-shaped diamonds retain more weight from the original rough than round diamonds, therefore the price-per-carat is less. Generally, with some market exceptions, fancy-shaped diamonds are priced less than rounds, and are therefore more affordable. Plus, elongated fancy-shaped diamonds appear much larger than a comparable size round diamond.