Diamond Glossary

Abrasion - A blemish, such as small nicks along the facet junctions.

A blemish, such as small nicks along the facet junctions (look whiter than the rest of the diamond), caused by impact damage. Excessive abrading often a sign that the stone is cubic zirconium, not diamond.

AGS – American Gem Society - One of the leading gemological labs.

The AGS (American Gem Society) is a diamond grading laboratory that issues diamond certificates. Founded in 1934 by a group of jewelers to promote gemological education, the AGS is currently headquartered in Las Vegas. While WP Diamonds grades to GIA standards, AGS is quite close to GIA on grading standards. Their reports detail the 4 C’s of your diamond.

Appraisal - An estimation of value of an item, typically for insurance purposes.

While this might be a good guide for the layman, appraisals are rarely, if ever, up to GIA standards for grading purposes. Furthermore, appraisals provide an indication, usually exaggerated, of the retail replacement value of an item, not the re-sale value.

Artificially Irradiated - See Irradiated Diamond.

Artificial irradiation is a color enhancement treatment. By bombarding a diamond with electron or neutron particles, this can change the atomic structure the stone’s crystal lattice, therefore changing the color of the stone. Most irradiated diamonds are yellow, green, black or blue in color. Any GIA certified irradiated stones will feature the word “irradiated” on the grading certificate.

While it is a good option for acquiring fancy colored diamonds at a fraction of the cost, they are not as valuable as a natural, untreated fancy colored diamond. Fancy colored diamonds are extremely rare and therefore expensive.

Asscher Cut - See Shape.

Asscher cut diamonds are a unique and striking diamond shape. First created in the early 1900’s, the Asscher did not rise in popularity until the 1920’s. It then fell out of favor during the Great Depression, only to reemerge as a popular cut in the early 2000’s.

There are two type of Asscher cuts: the Royal Asscher Cut (74 facets) and the standard Asscher cut (58 facets). Both were developed by the Royal Asscher Company.

The standard Asscher is a square emerald cut (or rather octogonal due to its cropped corners). With large step facets, the shape boasts strong brilliance. Much like emerald cut diamonds, any inclusions are highly visible so high clarity grades are recommended.

Baguette - See Shape.

Similar to (and often even confused with) emerald cut diamonds, the baguette cut is a rectangular shaped stone often featured in engagement rings. The baguette is is narrower than the emerald however and is typically a shoulder or accent stone rather than the center stone. For this reason, baguette diamonds are typically small in size.

This step cut stone often features 14 facets. It does not feature the same brilliance as the classic round brilliant cut diamond any flaws in the stone are easily visible.

Bearded Girdle - Small hairline fractures running from the girdle into the gemstone.

Also known as “bearding”. This is typically as a result of the cut and polishing process if it is done too quickly or without enough care. It can also simply be caused by general wear and tear. The girdle of a diamond is a vulnerable part of the stone and can chip or fracture over time. In order to avoid this, it is recommended that you have sufficient prongs as they protect the diamond. Mountings such as bezel sets also protect the stone efficiently. It also worth considering removing the ring if you know that you are about to partake in a physical activity in which your diamond could undergo damage.

Bezel - The large facets (second to the table) on the crown of a diamond.

A diamond’s crown (the top part of the stone) is made up of the table and multiple facets. Light enters through these facets and creates the shine and brilliance that round diamonds are renowned for. The bezel facets are located between the table and the girdle and are diamond shaped. Round diamonds typically have 8 bezel facets.

Black Pique - The black inclusions visible within a diamond.

These are more detrimental to the diamond’s value than white (or clear) imperfections. Despite this, a diamond grading report will often treat white and black inclusions the same for clarity grading purposes.

Blemish - An imperfection on the surface of a diamond.

A diamond can be internally flawless (IF), even if it has blemishes, including scratches, nicks and abrasions. Blemishes can usually be easily removed by polishing.