How Diamonds are Graded
Every diamond is unique, and display a wide variety of properties. Because of this every diamond must be evaluated to some degree to determine it’s value before it exchanges hands, or goes to market. As diamonds became more and more popular, and readily available, there became a great need for a unified grading system. This need lead to the establishment of the Gemological Institute of America (GIA) in 1931 by Robert M. Shipley. The GIA’s mission was and is to protect buyers and sellers of gemstones by creating and maintaining a set of standards used to evaluate gemstone quality. This was no easy task and required much research and innovation.
In 1933, Robert M. Shipley Jr. joined his father and began work on a low-power stereoscopic magnification microscope that utilized dark-field illumination. This equipment made it possible to begin evaluating stones in a much more detailed manner than ever before, and allowed the GIA to flourish as a research and education institute.
This new technology provided the platform for Richard T Liddicoat, Marquis Person, Joe Phillips, Robert Crowningshield and Bert Krashes to begin developing a new grading system they called the Diamond Grading and Evaluation Appraisal. By 1953 this system had been fully defined, and was released for use. It assessed four primary properties of a diamond and provided a universal platform for all gemologists to apply to diamonds.
While competition does exist, the GIA’s Grading system and certification remains the most globally accepted and sought after standard for white and rare colored diamonds.
Read the next article: 4C’s : Diamond Color