What Determines the Value of a Diamond?

Assessing the value of a diamond depends on many factors. The Cut, Color, Clarity and Carat weight (the 4 Cs) are standard factors established by the Gemological Institute of America (GIA). The GIA is a nonprofit, non-affiliated organization that provides educational, research and testing services to the diamond industry.

The Ideal Cut
Light* entering the diamond reflects internally from facet to facet and is reflected back through the top ONLY, creating maximum brilliance.

Inferior Cut
Most diamonds are "spread" in their cutting to retain maximum weight from the original rough. A heavier diamond will result, but at a dramatic sacrifice of potential fire and brilliance.

Too Deep
When a diamond is cut too deep, light* leaks out of the bottom, brilliance is lost and the center of the diamond will appear to be dark.

Too Shallow
When a diamond is cut too shallow, light* leaks out of the bottom, brilliance is lost and the diamond appears watery, glassy and dark.

*Arrows on the diagram simulate the flow of light in the diamond.

Most diamonds, although appearing colorless, actually have slight tones of yellow or brown. As these tones become more easily apparent, the rarity and the cost decrease.

Ideal cutting dramatizes the rare splendor of a diamond because it produces such dazzling brilliance.

Pratically all diamonds contain naturally occurring internal characteristics called inclusions. The size, nature, location and amount of inclusions determine a diamond's clarity grade and affect its cost.

One unique advantage of the Ideal Cut is that its sparkle can mask otherwise noticeable inclusions.

Color and Clarity diagrams courtesy of the Gemological Institute of America and the American Gem Society.

This word for the measurement of a diamond's weight is derived from the carob seeds that were used to balance scales in ancient times. A carat is equal to 200 milligrams and there are 142 carats to an ounce. Carats are further divided into points. There are 100 points in a carat. A half-carat diamond may be referred to as a 50-point stone (about 100 milligrams). Because large diamonds are rare, they generally have a greater value per carat.