The 4 C's When selecting a diamond, it is important to have an understanding of the 4 C's. But what are the 4 C's and what in the world do they actually mean? Here is a brief explanation of cut, carat weight, color, clarity, and what they mean when you are picking a diamond. Cut Carat Color Clarity   Cut refers to the placement and proportion of the facets, or surfaces. The facets reflect light and contribute to the diamond's sparkle. Cut gives your diamond its fire and brilliance. When a diamond is cut to good proportions, light reflects from one facet to another then radiates through the top of the stone. If the cut of a diamond is too deep, some light escapes through the opposite side of the pavilion. If the cut is too shallow, light escapes through the pavilion before it can be reflected, thus reducing brilliancy. Whichever shape you choose, you want the cut to maximize the diamond's brilliance. You'll be happy to know, you don't have to be an expert to judge the quality of the cut. Hold two diamonds side by side under a bright light. In general the one with the most fire has the better cut.