The loupe

TrueFacet's Fine Jewelry and Watch Guide

The Diamond Guide

TrueFacet Holiday Shops Sale

When evaluating a diamond, there are several factors that come into play that affect the quality and value of the stone. We in the industry like to call them the 4 Cs—cut, color, clarity, and carat. The following is a guide to help you use the 4 Cs to evaluate a diamond so you can better ascertain its worth.

Diamond Cut

A diamond’s cut refers to the angles a craftsman carves into a raw diamond to make it a polished diamond. These crucial cuts are rooted in scientific formulas and proportions designed to optimize the reflection and refraction of light within a stone. Of the 4 Cs, cut is considered the most significant factor in determining a diamond’s value, as it greatly influences the diamond’s fire, brilliance and scintillation.


Counterintuitively enough, color actually refers to a lack of color in a diamond, which can have a natural yellow tint. Therefore, colorless diamonds are rarer and more valuable. Color ranks as the second most important diamond characteristic, just after cut, which creates that immediately impressive sparkle.


Clarity refers to a ranked scale of perfection or how few blemishes and inclusions there are within the diamond. This rating is determined by the number, size and location of the imperfections relative to the size of the diamond and their overall impact on the appearance of the stone.



A carat is the unit of measurement for the stone’s weight—not its size. Although the term carat is the most frequently used when describing a diamond, it is not the most accurate representation of its overall value. The diamond’s cut grade and top diameter—or how big the stone will look when set in a ring—can give the illusion of a larger diamond.

To keep this guide handy, download the complete version here.