Understanding Diamond Carat Weight: The 4 Cs of Diamonds
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What is Diamond Carat Weight?

Carat is the unit of measurement for the physical weight of diamonds. One carat equals 0.200 grams or 1/5 gram and is subdivided into 100 points. For comparison, in units more familiar in the United States, one carat equals 0.007 ounce avoirdupois.

How Carat Weight Plays Into the 4 Cs and Diamond Value

Carat weight is the most objective of the diamond’s 4Cs. All that is required is a precisely balanced scale capable of measuring extremely small weights. In the AGS Laboratories, carat weight is measured using a highly accurate, and calibrated digital scale.

Here are some facts about a diamond’s weight and price that are important to understand before purchasing.

Comparing the value of diamonds by carat weight is like comparing the value of paintings by size. A wall-sized canvas by an unskilled artist may be bigger than a miniature by Rembrandt, but it will not be worth more. Large diamonds are rarer than smaller ones, and as the carat weight increases, the value of the diamond increases as well. However, the increase in value is not proportionate to the size increase.

For example, a 1-carat diamond will cost more than twice that of a ½-carat diamond (assuming Color, Clarity and Cut grade are the same). Weight does not always enhance the value of a diamond, either. Two diamonds of equal weight may be unequal in value, depending upon other determining factors such as Cut, Color and Clarity. In fact, if a diamond is improperly cut, the added weight may serve only to reduce its brilliance. 

The Bottom Line

The best way to see the difference in weight versus cut is to look at an AGS Ideal® cut diamond (be sure it comes with an AGS Laboratories diamond grading report to verify). Then look at the largest diamond in the store that is not an AGS Ideal® cut. You will see a noticeable difference.

Overall, it is important to consult an American Gem Society® jeweler or other credentialed jeweler regarding the weight, quality and value of a particular diamond.

Learn more about diamond buying.

 

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Mission Statement

The American Gem Society (AGS) is a nonprofit trade association of fine jewelry professionals dedicated to setting, maintaining and promoting the highest standards of ethical conduct and professional behavior through education, accreditation, recertification of its membership, gemological standards, and gemological research.

The Society is committed to providing educational products to inform and protect the consumer and to contributing to the betterment of the trade by creating industry standards to protect the jewelry-buying public and the fine jewelry industry as a whole.

AGS Laboratories, founded to support the AGS mission, is a nonprofit diamond grading laboratory with a mission of consumer protection. Adhering to the AGS Diamond Grading Standards, AGS Laboratories is dedicated to offering diamond grading reports that provide consistency and accuracy based on science.

American Gem Society

8881 W. Sahara Ave. Las Vegas, NV 89117

info@ags.org (866) 805-6500