Diamond Glossary

Table - the large facet at the top of the diamond.

A diamond’s table is the largest facet on the stone. Located at the very top of the diamond, it plays a pivotal role in the appearance of the stone and how it refracts light. A table that is too large will not disperse light effectively and a table that is too small will not allow enough light into the stone. The table percentage is calculated by dividing the table width by the total diamond width. The ideal table percentage varies depending on the shape.

Table Percentage -

For a round brilliant cut, the average width of the table as a percentage of the average diameter of the diamond. For fancy shapes, it is the width of the table as a percentage of the width of the entire diamond.

Treated Diamond - a diamond that has been altered to affect color or clarity.

Diamonds that have undergone a treatment to enhance either the color or clarity of the stone are called treated or enhanced diamonds. While this helps improve the visual appeal of a stone, it has a negative impact on the value of it. The reason being is that untreated diamonds with high color or clarity grades are rare and therefore valuable. Diamonds that have been altered to improve color or clarity are not as rare and therefore are less valuable. Any paperwork you have on your diamond should make reference to these treatments if it is a treated diamond.

Common clarity treatments include laser drilling and fracture filling. Laser drilling involves creating a small hole in the stone to access the inclusion and treat it. Fracture filling involves adding a glass-like resin to close any fractures of cracks in the diamond. This is not however a permanent treatment and over time, the substance can darken, thereby worsening the clarity.

See Irradiated Diamond. See Color Enhancement.

Trillion Cut - See Shape.

Often used as side or accent stones, the trillion cut is a triangle shaped diamond. Created in the Netherlands, this striking, geometric shape can also be used a center diamond to create a truly unique piece of jewelry.

The advantage of a trillion cut is that it looks substantially larger than a round diamond of the same carat weight. The reason being for this is that trillions are shallow and wide. The disadvantage to trillion cuts, however, is they the are prone to chipping due to their sharp corners. Therefore it is important to pay particular attention to the mounting chosen as this can help protect those vulnerable corners.

Twinning Wisp - a series of pinpoints and/or clouds that form in the diamond’s growth plane.

This is a clarity characteristics that negatively impacts the diamond’s value.