Diamond pricing involves many detailed calculations and evaluations. Price determination is largely dependent on the 4Cs: color, cut, clarity and carat weight. In addition, there are several other notable factors, including shape, fluorescence, polish, symmetry, girdle thickness, culet size, and special cuts. Finally, GIA certification is important.

The 4Cs

Furthermore, there are several other important characteristics to consider, including shape, fluorescence, polish, and symmetry.


A diamond's shape will influence its price. There are a variety of diamond shapes, with certain ones more popular than others, like the round brilliant, princess cut, oval cut, and radiant cut. Other popular cuts include the vintage cushion cut diamond. The more popular the shape, the more expensive the diamond.


Fluorescence is another factor that influences price. It occurs when a diamond emits a faint glow under a black or ultraviolet light. Fluorescence is often considered a defect and can lower a diamond's price.


Polish refers to a diamond's luster and affects its ability to reflect and retract light. The harder the diamond, the greater the polish. Like other diamond aspects, polish is graded on a scale. A poorly-polished diamond will appear duller than one that is well-polished. This will impact the price.


Symmetry is graded on a scale almost identical to polish. Poor symmetry will negatively affect how light travels through a diamond and will yield poor brilliance. Excellent symmetry will yield superb brilliance.

Girdle Thickness

Girdle thickness refers to a diamond's outermost edge, which can be thin, medium, or thick. If the girdle thickness is too thin, the diamond will chip easily. If it is too thick, the diamond may appear smaller than it actually is. An ideal diamond will have a medium girdle thickness.

Culet Size

The culet is a small tip that occurs at the base of a diamond's pavilion. Most diamonds will have nicely cut pavilion facets, leaving no culet. A diamond with a large culet will have more facets than a diamond with one that is small and pointed, making it visibly less attractive. An ideal diamond will not have one.


The final factor in the diamond-pricing process is certification. Each diamond is unique and individually certified. The process involves examination by a professional gemologist, who will grade each diamond based on its multiple characteristics, like those stated above. Each diamond is issued an individually-numbered certificate that details its traits. Once it is certified, the buyer can be confident that the diamond is authentic and high quality.

Note: Don't confuse a certification with an appraisal. A certification evaluates a diamond's quality and characteristics, while an appraisal determines market value.

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