Get to Know: Diamond Grading
If you're in the market for diamonds, we are sure you have questions and may not know where to start. The key to understanding diamonds is understanding the four Cs (the four attributes diamonds share): Color, Clarity, Cut, and Carat Weight. The Gemological Institute of America, also known as GIA - the largest and most respected institute of geological research, developed the four Cs to create a universal language when it came to the difficult task of determining diamond quality.
Now on to the first C...
1. Color: When it comes to diamonds, elements can be trapped in the crystallization process and the elements cause color in the diamond. In general, the less color a diamond has, the more rare and valuable it is. However, in very few diamonds the foreign elements can saturate the color enough to where we would call the color "Fancy" i.e. "Fancy Pink". The GIA color scale classifies diamonds from "D" colorless to "Z" light yellow or brown. At the GIA lab, a color grade is determined by comparing each diamond to a master set of diamonds that represent the color grades on the GIA scale (featured below).
2. Clarity: The GIA clarity scale includes 11 clarity grades ranging from flawless to I3. Flawless indicates that there are no inclusions or blemishes visible at 10 times magnification. A grade of I3, is for diamonds with inclusions that are obvious to the naked eye. A 10 times magnification loop and a microscope are used to see and plot the inclusions. Since no two diamonds are exactly alike, this unique plot helps identify a particular stone. Graders also look to see if there is any evidence that the diamond was treated to improve its clarity.
3. Cut: The third C is cut. The GIA cut scale is used for round brilliant cut diamonds and consists of five grades ranging from excellent to poor.
Many think the cut is in regards to the shape of the diamond like square cut or round. However, there is much more to cut than the basic shape. How a diamond is cut and polished directly affects the amount of sparkle and brilliance that comes off the stone. Each diamond is placed in a highly precise measuring device that rotates the stone 360 degrees to capture hundreds of measurements and facet angles. GIA developed a comprehensive system that factors the diamonds proportions as well as its culet size, girdle thickness, polish, and symmetry descriptions which generates a GIA cut grade.
4. Carat Weight: We've made it to the final C, carat weight! 1 carat equals 100 points. Like pennies to a dollar, 100 points equals 1 carat. You may hear terms like "92 points" which means that stone is just under 1 carat in weight. Each diamond is placed in a sealed chamber and weighed on an extremely precise electronic scale. All other "C's" being equal, the greater the carat weight, the more rare and valuable the diamond will be.
Buying a diamond is an exciting and enjoyable process, just keep all the four Cs in mind: Color, Clarity, Cut, and Carat Weight to ensure you're picking the best diamond for your budget.