BLACK DIAMOND GRADING & CERTIFICATION

Black diamonds have a distinct construction, typically have inclusions and are opaque. A perfectly flawless black diamond does not exist. Therefore while grading black diamonds only the clarity of the table and crown that is the face of the black diamond is considered. Since the diamonds are opaque the inclusions below the girdle do not influence the face of the stone and can be easily hidden under the settings.

Clarity or purity refers to how clear and void of inclusions is the diamond. In black diamonds, however, more crucial is the locations and visibility of the inclusions. Black diamonds typically have inclusions that may or may not show on the surface. As long as the inclusion is not disrupting the shape, color or face (top surface) of the diamond the diamond can be graded high.  There can be like gray spots, scratches, pits, cleavages, cracks, clouds, cavities, crystals, feathers, surface grains etc. Learn more about the inclusions here…

Color is the second most crucial criterion for grading black diamonds. The best quality diamonds have a uniform and lustrous mid-night black color; however it a rare exception.   Most diamonds when mined are either gray, dark green, charcoal sometimes even muddy white. These diamonds are therefore treated to get a rich black color. Apart from the color being dark it is equally important that it should spread across the diamond uniformly. The diamonds with gray or white color patches are not considered good. Black diamond color is usually referred to Fancy Black, as its one of the fancy colored diamond.

Shape or cut of the black diamonds is equally vital. A disproportioned or off-shaped diamond does not sell. Though a slight defect can be covered by the setting but major defects affect the diamond grading. The problem of disproportioned occurs only when there is an inclusion at a crucial place of the diamond. The cutters are compelled to retain or camouflage the inclusion to avoid the breaking of the diamond or decreasing the carat weight.

Carat weight– Black diamonds are rare and larger stones are even rare. So like all diamonds, the cost of the black diamond too escalates with the size of the diamond. The bigger the diamond the higher will be the price considering the other grading factors as well. Another interesting point to note here is that black diamonds are denser and are therefore heavier. A white diamond of a particular millimeter size will weigh more than the black diamond of the same size.

Click to view the full certificate

*All black diamonds are graded for the table and crown of the diamonds. The grading does not include the pavilion, girdle or culet of the black diamonds.

AAA – Quality Black Diamonds, They are of solid black color and have minor or no face up inclusions on the table of the stone. There are no cavities, feathers and / or clouds on the table of the diamond. These diamonds are Jet Black in color. Surface is very clean, however rarely you will find very slight inclusion on surface facets. The diamond is nicely and proportionally cut. All black diamonds are graded for table and crown of the diamond. We do not grade the pavilion, girdle, or culet of black diamonds. This grade of Black Diamonds is considered amongst the best Black Diamonds in the world.

AA – Quality Black Diamonds have minor white spots visible or other minor flaws. These may include a cavity on the crown of the stone, but not on the table of the stone. These stones are black in color – fairly clean surface some stones with slight surface inclusion. Nicely and proportionally cut. All black diamonds are graded for table and crown of the diamond. We do not grade the pavilion, girdle, or culet of black diamonds. This grade of Black Diamonds are considered of Very High Quality

A – Quality Black Diamonds may have cavities, feathers, and / or clouds on the table or crown of the stone. These stones are black to pale black in color. Internal or surface inclusion visible. Nicely cut. All black diamonds are graded for table and crown of the diamond. We do not grade the pavilion, girdle, or culet of black diamonds. This grade of Black Diamonds is a medium high quality.

B– Quality Black Diamonds have heavy cavities, feathers, and / or clouds on the table and the crown of the stone. These stones are black to pale black in color. Internal and external surface Inclusions are visible. Cut is not perfect round. All black diamonds are graded for table and crown of the diamond. We do not grade the pavilion, girdle, or culet of black diamonds. This grade of Black Diamonds is considered of medium low quality.

C– Quality Black Diamonds have heavy cavities, feathers, clouds on the table and the crown of the stone. These Diamonds are black to pale black in color. Internal and external surface inclusions are visible. Cut of this diamond is off round. All black diamonds are graded for table and crown of the diamond. We do not grade the pavilion, girdle, or culet of black diamonds. This grade of Black Diamonds is considered of low quality.

Labs Grading Black Diamonds

Black Diamonds largely sold in the market are not graded. However, the following labs do the grading of black diamonds-

GIA- Gemological Institution of America –  Only grades natural unheated-untreated natural black diamonds Click here to view a sample GIA Certificate for Black Diamonds

EGL- European Gemological Laboratories Grades all black diamonds and have also developed the standards and quality grades Click here to view a sample EGL Certificate for Black Diamonds

One thought on “BLACK DIAMOND GRADING & CERTIFICATION”

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>