Grading Diamonds:
The Four C's

Each of the 4Cs impact the diamond's appearance and price, so knowing how they interact with each other can help you find a diamond that is both beautiful and within your budget.

The precision to which diamond is cut is what determines its brilliance or sparkle.  More specifically, cut refers to the angle that each facet is cut to and how well all of the facets
work together to reflect the light back to a viewer’s eye as sparkle. Before a diamond is cut, the location of inclusions, the natural coloration, and the original shape of the rough stone are studied extensively. The stone facets are then mapped out and cut in a way that maximizes size, shape, clarity and, when done well, sparkle.

A diamond is distinguished by its natural characteristics, just as a person would be noted for her blue eyes or his brown hair. Notated as a diamond's clarity, these characteristics can be present on the surface (blemishes) or within the stone (inclusions).

The clarity of a diamond is judged by the nature and location of these characteristics and is designated using a scale that runs from FL, defined as flawless, to I3, defined as inclusions visible with the naked eye.

A diamond's clarity grade is determined while a grader views the diamond under 10X magnification. You'll therefore hear a clarity characteristic referred to as "eye visible" or a diamond being "eye clean", this is of particular importance because the diamond you choose will be most frequently viewed by your "naked eye", without magnification. 

Pay close attention when inspecting a diamond graded SI1 and below because this is when a diamond’s characteristics may be visible to the naked eye depending on their nature and location.

Pro tip, be particularly cautious of diamonds with the same lab grading when one diamond's price seems low, the nature and location of the characteristics is often times the reason.

Diamonds are graded based on the amount of body color they display in the table down position, against a white background. The scale runs from D (colorless) to Z (light yellow).

The unit of measure used for the weight of a diamond is the carat. As a matter of reference, a carat is equivalent to .2 grams or .007 of an ounce. Carat weight can also be divided further by using points. There are 100 points in one carat. So a 1/4 (.25) carat diamond can also be expressed as 25 points and mean exactly the same thing.

When comparing diamonds, please note that carat weight does not directly correlate to total diameter; meaning, just
because one weighs more than another does not mean that it will appear larger, in fact, it may appear smaller depending on its diameter.

While not one of the 4C's, the shape of the diamond is often confused with the cut. Diamonds come in a variety of shapes, each with its own unique characteristics and appeal. The most popular diamond shapes include round, princess, cushion, emerald, pear, marquise, oval, and heart. Round diamonds are the most popular due to their brilliant sparkle and versatility. Ultimately, the choice of diamond shape is a personal preference and should be based on the individual's style and taste.