How to Compare Loose Diamonds

Same-sized diamonds may have different costs depending on their quality.

When you compare diamonds, take into account the Four C's. The Gemological Institute of America's grading scale is the industry standard for determining the quality of diamonds.

Carat

Diamonds are weighed in metric carats. One carat is equal to 0.2 grams. Using extremely sensitive scales, diamonds are typically weighed to the hundred-thousandth of a carat and rounded to a hundredth of a carat. Larger diamonds generally have a higher value.

Color

The less color a diamond has (meaning no hints of yellow or brown), the more it's worth. The Gemological Institute of America's color-grading scale begins with the letter D, representing colorless, and ends with Z, representing near colorless. Fancy diamonds, which come in colors such as blue and pink, are the exception and generally cost more.

Clarity

Clarity is a crucial factory in diamond quality. The Gemological Institute of America's International Diamond Grading System grades clarity from flawless (FL) to diamonds with obvious inclusions (I3). There are 11 grades that may be given based upon how easily marks and blemishes are able to be seen under 10X magnification.

Cut

The cut determines the brilliance, fire and scintillation of the diamond; the cut is judged based upon the diamond's proportions, polish and symmetry. Diamond-cut grades include excellent, very good, good, fair and poor. Cuts can come in shapes such as round, emerald, pear, heart and princess.

References

• The Gemological Society: About the Four C's
• Adiamor: Diamond Cut
• Diamond Ring: The Four C's Plus One