high quality cut diamond that reflects the light beautifully

The 4C's of Diamond Quality

As early as the 1900's there was no standard method for judging diamonds. It wasn't until the middle of the century that the Gemology Institute of America (GIA) created the first method. Today, their 4C's system is the universal standard for understanding and assessing the quality of any diamond in the world. So what does each 'C' mean and how do they relate to quality?

Understanding the 4C's of Diamond Quality


Color actually refers to the lack of color. To better understand, let's compare a diamond to a droplet of water. A droplet of chemically pure and structurally perfect water has no hue. The 4C's system uses a D-Z color grading system that measures colorlessness under controlled lighting. The system begins with a grade of D, which means the diamond is as colorless as it can get. The presence of color increases ever so slightly all the way to a grade of Z. While differences in color may not be obvious to an untrained eye, the price will reflect it.


Clarity refers to the absence of inclusions and blemishes, which are internal and external imperfections (respectively). Diamonds are the result of carbon that has been exposed to an incredible amount of pressure. Naturally, this will cause such imperfections. Keep in mind, though, that this means there is no such thing as a truly perfect diamond. The closer a diamond is to perfection, the more valuable it is. 


Judging the cut of a diamond has less to do with shape and more to do with how well it reflects light. This grading scale ranges from Excellent to Poor. When a diamond receives a grade of "Excellent" it possesses an even pattern of bright and dark areas. Brightness refers to the amount of internal and external white light it reflects. The grading scale for assessing the cut of a diamond also takes into account "Fire", which is defined as the scattering of white light into all the colors of the rainbow, and scintillation, which refers to the amount of sparkle a diamond produces.


Carat is perhaps the simplest to understand of the 4C's and refers to weight. A single carat measures about 200 milligrams, and in general, a diamond will increase in price as its carat weight increases. This is because heavier diamonds are so rare and more desirable.

Consult a GIA Certified Gemologist at ALKU Jewelers

We take pride in the diamonds we curate. They are so perfectly cut that they reflect up to 93% of incoming light. How a diamond is cut can affect its price by over 40%, so book your spot at our appraisal clinic on September 19th to have a GIA Certified Gemologist thoroughly evaluate your item. This way you can understand and protect its quality.