Engagement Ring Prep: The 4C’s

Developed by the Gemological Institute of America ("GIA") in the 1940's, the 4C's of Diamond Quality is the industry-wide method of determining a white diamond's quality and value. These 4 characteristics include: carat, clarity, color, and cut. The grading system is a guideline, rather than a "good" or "bad" scale. The higher the stone is to the top of the scale, the more expensive it will be BUT not necessarily the more beautiful. What matters the most is what you think of the diamond! We broke down the 4C's to help you determine what your perfect diamond is.


The carat is the term used to describe the weight of a gemstone. Carat with a C is not to be confused with karat with a K, which is the term to measure the purity of gold.

For those of you interested in the measurement breakdown: one carat equals 1/5 gram, and is subdivided into 100 points. So a "50-pointer" is a 1/2-carat stone (.50ct).  Examples of .60ct through 1.5ct diamonds set in bezels are shown below.

There is a general correlation between carat weight and the physical dimensions of a diamond: the heavier the stone, the larger the stone. However, it's not exactly linear. Every stone carries their weight in a different way - so, if we have two stones that each weigh exactly 1ct, they might have different diameters because of their unique proportions. We refer to the surface area face-up as the "spread" of the diamond. A diamond with a larger spread will tend to be shallower, and may have less light refraction with less depth. This is why it's so important to see stones in person! You can't always tell what you're getting by the numbers or lab report grading.


Diamond clarity refers to the tiny imperfections found on the interior or exterior of the stone called inclusions. Clarity is graded on a scale from Flawless to Included. A diamond doesn't have to be at the top of the scale - Flawless or Very Very Slightly Included (VVS) - to be crisp and clean to the naked eye. The color and location of an inclusion can greatly affect its visibility. Many inclusions are imperceptible to the naked eye and hidden by the diamond's light refraction, only evident under magnification. We use the term "eye-clean" to describe this kind of stone. 

Below is a comparison of an included diamond (left) and an eye-clean diamond (right).


The color of a diamond is graded on a scale from D-Z with D being colorless and Z with a faint yellow or brown color. Colorless diamonds are the most rare and the most expensive. This D-Z range of colors applies specifically to white diamonds. Other colors like pink, yellow, or even blue diamonds are in a completely different category of Fancy colored diamonds. Similar to clarity, there are often imperceptible changes from one color grading to the next. We most often work with diamonds with a grading in the G-H-I range to achieve that bright white diamond look, but also enjoy exploring warmer tones as shown below.


This doesn’t refer to the shape (pear, oval, etc), but the symmetry, proportioning and polish of the diamond.  The cut of the diamond affects how the stone reflects the light and how it sparkles - its "brilliance". This means if the diamond is cut poorly, it will be less luminous.