GIA created the first diamond grading scale and is not the most accepted standard for diamonds. The four describing characteristics of a diamond are: Color, Clarity, Cut, and Carat Weight. The 4 C’s is now the universal method of assessing the quality of a diamond. The 4 C’s has done two very important things for the industry: diamond quality is now universally understand all over the world, and diamond purchasers now know exactly what they are viewing and purchasing.
Diamond Color Actually Means Lack of Color
The first step to understanding a diamond quality is the color, or the lack thereof. A chemically pure diamond has no hue of yellow tint, which makes it more valuable and rare. The GIA color grading system measures form D-to-Z. The diamonds color quality is viewed under controlled lighting and perfect viewing conditions while being compared to masterstones of established color value.
The distinct color differences between color grades can be hard to detect to an untrained eye. These distinct differences make a very big difference between quality, price, and rarity. It is important be educated by a professional in the GIA grading scale when viewing diamonds.
Diamond Clarity Refers to the Absence of Inclusions and Blemishes
Natural diamonds are created through the process of carbon being exposed to tremendously high heat and pressure in the earth. The process has a variety of impacts on the diamonds called “inclusions” “blemishes”. Inclusions are the internal characteristics and blemishes are the external characteristics of the diamond. The clarity of a diamond is figured by the size, number, nature, and position of these characteristics. These characteristics also affect the appearance of the diamond. No diamond is perfectly pure, but the closer it becomes to pure the better the clarity grade and rarity.
The GIA scale has 6 categories for clarity, making up 11 specific grades.
-Flawless (FL) No inclusions or blemishes visible under 10x magnification
-Internally Flawless (IF) No inclusions visible under 10x magnification
-Very, Very Slightly Included (VVS1, VVS2) Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
-Very Slightly Included (VS1, VS2) Inclusions observed with effort under 10x magnification
-Slightly Included (SI1, SI2) Inclusions are noticeable under 10x magnification
-Included (I1, I2, I3) Inclusions are obvious under 10x magnification and be viewed by the naked eye
Understanding Diamond Cut
What makes a diamond sparkle is it’s ability to transmit light. A diamond’s cut refers to how well a diamond’s facets interact with light. A diamond cutter has precise artistry and workmanship to cut diamonds proportions, symmetry, and polish the best possible way to get the most sparkle out of a diamond. The proportions allow GIA to evaluate what the best cut for a diamond is, by studying how a diamond interacts with light to create desirable visual effects, such as:
-Brightness: Internal and external white light reflected from a diamond
-Fire: The scattering of white light into all the color of the rainbow
-Scintillation: The amount of sparkle a diamond produces, an the pattern of light and dark areas caused by reflections within the diamond
Also included in the cut is the diamond’s weight relative to the diamond, it’s girdle thickness, the symmetry of it’s facets, and the quality of polish of those facets. The GIA cut grade is as following: Excellent, Very Good, Good, Fair, and Poor.
Diamond Carat Weight Measures a Diamond’s Apparent Size
A diamond carat weight is measured by how much a diamond weighs. A jeweler may describe the weight of a diamond by it’s “points”. For example a diamond may be referred as a 50 pointer (.50 carats). Diamond price increases with diamond carat weight because larger diamonds are more rare and more desirable. However, two diamonds with the exact same carat weight can have drastic price difference depending on the three other factors of the 4 C’s. There are some weights that are considered “magic sizes”: half carat, three-quarter carat, and carat. Visually, there’s little difference between a .99 carat diamond and on that weighs a full carat.
Every GIA graded diamond is completed using the GIA diamond grading scale. The diamonds are graded by a professional diamond grader using masterstones for each of the 4 C’s: Color, Clarity, Cut, and Carat Weight.