Diamonds and the Four Cs
The Four Cs of diamonds are the building blocks of diamond education and the beginning of understanding how diamonds are compared and ultimately valued. Created in the 1950's by the Gemological Institute of America (GIA) (of where I am also a graduate) the 4Cs are the universally accepted method of grading diamonds.
The four Cs are: cut, color, clarity, and carat weight
Cut: Cut refers to the craftsmanship that brings a rough diamond that looks like a garden rock alive and gathers light around the stones. In a round diamond (the most popular shape) there are 58 facets, or tiny prisms, that gather and reflect light. An ideally cut diamond absorbs light and reflects it with brilliance unlike anything you’ve ever seen. A diamond cut too shallow or too deep allows light to leak out through its bottoms and sides.
Color: Diamond color is graded with a letter scale ranging from D to Z. Those graded D to F are considered colorless; G to J, near colorless; and K to Z has a noticeable tint. As you may have guessed, a diamond with little or no color is a more expensive diamond. Diamonds with absolutely no color at all are incredibly rare.
Clarity: Most every diamond contains tiny trace minerals, fractures, or other slight imperfections (called inclusions) that are a natural part of its growth process. Gemologists grade diamonds for clarity, just as they do with color, on a scale ranging from FL (flawless) to I3 (prominent inclusions). Most inclusions are unnoticeable to the naked eye.
Carat: Diamonds are measured in carat weight, part of the metric system of measurement. One carat is equal to a fifth of a gram. Larger diamonds a rarer to discover in a mine and so they tend to be more expensive; but that doesn’t mean that a diamond with a larger carat weight is necessarily a better gem. A higher carat weight diamond can easily be a poor specimen without a high cut grade, because a poorly cut, no matter the weight, can appear dull and lackluster.
When you know a diamond’s Four Cs, you can easily compare it to others and better determine its value. However, the Four Cs only describe the measurements of a diamond. They do not tell you if the diamond sparkles with fire and brilliance, or if it's hazy and dull. Only by seeing the diamond and holding it in your hand can you truly determine its beauty.