How to Check a Diamond's Cut

Cutting diamonds is both mathematically precise and elegantly artistic. The cut of a diamond does not refer to its shape (heart, round, pear, etc.), but to the number of facets, the measurement and proportion of the stone and its reflectivity. The best cut diamonds sparkle with fire, as light enters the stone and reflects back. The quality of a diamond's cut is the most important of the four Cs that determine a diamond's quality and value (the others are clarity, color and carat). It is also one of the most difficult qualities to determine with the untrained eye.

Instructions

1

Ask your jeweler or stone vendor for the certificate that accompanies your stone. Most diamonds will have been examined by an appraiser from a reputable firm like the American Gem Society. The firm will rank a diamond's cut from Ideal to Poor, depending on the cut's proportions.

If you are attempting to check the cut of an heirloom diamond or a stone that does not have a certificate, the AGS website offers a database of certified inspectors or laboratories where your stone can be examined and graded.

2

Examine your diamond, either with the naked eye or a jeweler's loupe under direct sunlight or a bright indoor lamp. An ideal cut diamond will sparkle and shimmer in the light, while a poorly cut diamond will seem dull and lack brilliance.

3

Familiarize yourself with different cuts of diamonds and the different levels of brilliance in each ideal stone. While many brilliant cut diamonds (usually round, marquise or pear-shaped stones) are particularly fiery, emerald, baguette and Asscher cut stones do not reflect light in the same way. Each diamond cut reflects light differently, so don't expect a baguette cut stone to sparkle like a round brilliant diamond.