Diamond Terms to Know

A GLOSSARY OF DIAMOND TERMS

Blemish: Blemishes are the external flaws of a diamond that are identified and used to help determine its clarity.

Brilliance: Refers to the flashes of refracted white light through a diamond. This is the diamond's ability to reflect white light. The brilliance of the diamond increases when greater amounts of white light are reflected off its table and to the eye. This contributes to a diamond’s sparkle and its impressive, beautiful features. 

Carat (ct.): This is the international standard used when measuring the weight of diamonds. When referencing a diamond smaller than one carat, jewelers often refer to the weight as points. One-half carat would be referred to as 50 points. 

Cut: A diamond’s cut consists of two necessary parts. 1. The external shape and style of the gemstone; pear, marquise, princess, etc. 2. Proportions, often called the “make.” This relates to how effectively the diamond is cut and polished to produce maximum beauty.

Certification: To identify characteristics of a diamond at a certain point in time, an independent laboratory created a reference. GIA refers to it as a diamond grading report. Also called a “cert.”

Color: Although many think of diamonds as white, they come in a variety of colors. Diamonds range from colorless to light yellow. The rarity of a diamond is dependent on the lack of color within the stone. 

Clarity: A diamond’s size, type, number, location, and the relief of the unique external and internal features of the gemstone determine the clarity. No two gems are alike, similar to a human fingerprint, your diamond is just as unique as you.

Crown: This is the area above the girdle on a polished diamond where the light enters. The brilliance that begins on the crown can affect the diamond’s appearance immensely. 

Dispersion: Separated into spectral hues of red, orange, yellow, green, blue, and violet, the white light inside of a diamond appears as tiny flashes in color. This dispersion is also known as fire in a diamond. 

Facet: The polished flat surface of a diamond is known as a facet. A brilliant round cut diamond roughly has 58 facets. 

Fire: A diamond’s ability to disperse colored light is known as fire. 

GIA: Known formally as the Gemological Institute of America. This is a non-profit organization whose mission is to educate, provide laboratory services for the jewelry industry, and to secure the trust of the public. 

Girdle: The term girdle is used to define the widest part of the diamond. This is the perimeter of the diamond. The diamond’s girdle is the part that is used to hold the stone in place in a ring setting.  

Inclusion: The gem’s clarity is determined by the internal characteristics known as the inclusions. 

Pavilion: The pavilion is the area below the girdle. Defined due to the noticeable “V” shape of the base of the diamond, this part serves as the part of the stone that reflects light back through the crown at the viewer. 

Point: Similarly to the decimal system, a point is 1/100th of a carat. A carat diamond is 1.00 carat.

Scintillation: Due to movement, flashes of light, known as scintillation, are reflected from the diamond. 

Table: The largest facet on a diamond is known as the table. On a round brilliant cut diamond, its table is in the shape of a stop sign. 

The 4C’s: The value of the diamond is determined by the combination of its characteristics, referred to as the 4 C’s—the cut, color, clarity, and carat weight. 

Total Weight: If there are multiple gemstones in one piece of jewelry this will contribute to the total gem weight of the item. Commonly abbreviated as “CTW,” “CWT,” “TW,” or “TDW.”