What are the four C's for rating a diamond?

First, it is important to note that the Gemological Institute Of America (GIA) is a non-profit gem research institute dedicated to providing a variety of gem grading and identification reports to businesses and jewelry companies. Each specific diamond grading report that is made is for an unmounted natural or synthetic diamond. Each report must specifically and directly refer to a diamond's key characteristics: color, clarity, cut and carat weight (four C's).

When GIA diamond grades are established and used, the grades always affect the diamond's ultimate price. Each report on the four C's (carat weight, cut, color, clarity) is accompanied by a diamond chart illustrating the differences between the grades.

Until the middle of the 20th century, there was no agreed-upon standard by which diamonds could be judged. GIA created the first, and now globally accepted standard for describing diamonds. Today, the four C's of rating diamond quality is the universal method for assessing the quality of any diamond, anywhere in the world.

The basic creation of the diamond four C's meant two very important things: diamond quality is communicated in a universal language, and diamond customers are clearly aware of the exact characteristics of any diamond that they are about to buy.