Diamond professionals use these four factors to describe and classify diamonds. Combined together, they help you to make an informed decision when it is time to purchase your actual diamond.
The Color Scale spreads from D (colorless) to Z (light yellow or brown). Truly colorless diamonds are very rare and as a result very expensive. Most diamonds used in jewelry are nearly colorless with tints of yellow or brown. Color grades are determined by comparing each diamond to a master set. Each letter grade represents a range of color and is a measure of how noticeable a color is.
The Clarity Scale extends from Flawless to I3. Diamonds form under extreme heat and pressure, and it is extremely rare to find a diamond that does not have any internal or external characteristics. These characteristics are a byproduct of its formation and help professionals separate natural diamonds from created diamonds, in addition to helping identify individual stones. Flawless stones are rare and are treasured for their rarity and beauty. Diamonds with very, very small inclusions are graded as VVS1 or VVS2. As you can guess, as the inclusions become larger and more numerous, the lower the grade and the less rare the diamond. Inclusions that can be seen with the naked eye are graded I1 to I3.
The Cut Scale extends from Excellent to Poor. One of the greatest diamond's quality and beauty comes from a complex relationship with light. The way how light strikes the surface, the amount that enters the diamond, and how, and in what form light returns to the observer. Diamonds with fine proportions, symmetry, and polish optimize their interaction with light, and have increased brightness, fire, and scintillation. All of this rest in the hands of a skilful diamond cuter. When a diamond is cut to good proportions, light will reflect from one facet to another and disperse through the top of the stone, resulting in a display of brilliance and fire. Diamonds that are cut too deep or too shallow lose light that spills through the side or bottom. As a result, poorly cut stones will be less brilliant and less valuable, than well cut diamonds higher on the diamond scale.
Diamonds are weighed in Carats. The origin of the word and weight unit was first used by ancient merchants in the Middle East approximately 500 B.C. The unit weight used for diamonds and other precious stones then was determined by the equal weight of the carob seed. The weight of a seed from the seed pod of the carob tree or locust bean tree was uniformly equivalent too one carat in weight or 200 milligrams. For diamonds less than one carat, each carat is divided into 100 points. Thus 0.75 ct. = 75 points = 3/4 ct., 0.50 ct. = 50 points = 1/2 ct.