While diamonds are among some of the most rare and valuable stones in the world, chances are if you have jewelry, it is likely set with them!

To help explain the four primary rarity characteristics that influence a diamonds value - color, clarity, cut and carat - let’s start by looking at the charts, provided by Gemological Institute of America, pictured below.

To help explain the four primary rarity characteristics that influence a diamonds value - color, clarity, cut and carat - let’s start by looking at the charts, provided by Gemological Institute of America, pictured below.

As you can see, with the exception of fancy colored diamonds (we’ll cover that topic later), all diamonds are graded for color (or the lack thereof) by using an alphabetical chart. This chart starts at D and ends at Z. Groups of these letter grades are combined into color ranges, with DEF being called ‘Colorless’, GHIJ ‘Near Colorless’, KLM ‘Faint’, N-R ‘Very Light’ and S-Z ‘Light’. Often, yellow tones will account for a diamonds 'color’, although other tones such as brown, green and grey (silver) can also be present.

Following color is clarity. You may have heard clarity referred to as a diamonds ‘imperfections’, ‘carbon spots’ or ‘purity’. These terms can be a bit misleading. Rather, a diamonds clarity grade simply indicates what level of natural characteristics are present within a given stone. The prevalence of these characteristics fall into categories, or clarity grades, from visible to the naked eye (I1-I3), to invisible under 10x magnification (VVS1-IF).

While three of the four ‘C’s are factors solely controlled by nature, the ‘C’ for cut is the only rarity factor controlled by man. Cut refers to two important descriptions of a diamond: its literal shape of cut (e.g. round brilliant, princess cut, oval, etc.) and the mathematical proportions to which that shape was cut to. Because cutting takes many, many years to master - very few diamonds are cut to mathematically ‘excellent’ standards, making how a diamond is cut a factor in how it is valued.

Lastly, and the perhaps most well know ‘C’ is carat weight. For perspective, one carat (1.00ct) is equal to 1/5th of one gram. But, as even 1.00ct diamonds are rare, carat weight can be expressed in even smaller units know as ‘points’ within the trade. A ‘point’ is a unit of weight that is 1/100th of a carat - or 0.01ct. Like there are 100 pennies to a dollar, there are 100 ‘points’ to a carat.

If this information was helpful, be sure to check out the additional posts featuring GIA video content about each of the ‘4Cs’ individually as well as the history of how the ‘4C’ diamond grading system was established!

For additional information about GIA and the 4C’s of diamonds, visit: 4cs.gia.ed