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Diamond Color

How to Evaluate Diamond Color

By , About.com Guide

diamond color grades

Diamond Color Grades

Not exact, of course.

Diamond Color

Diamond color is one of four major characteristics that are considered when determining a diamond's quality and value. They are known as the Four C's, and the remaining three are diamond clarity, diamond cut, and diamond carat weight. Understanding these four diamond characteristics and how they interact will help you select a diamond that suits your tastes and your pocketbook.

Diamond Color Differences

Diamonds are not all truly colorless, but it's the colorless diamonds, sometimes called white diamonds, which all other shades are judged against.

The Gemological Institute of America (GIA) has devised a set of guidelines to grade diamond color. The color of graded diamonds is compared to the color of control stones, which are preselected gems of a specific color.

Diamond Color Grading Procedure

  • To be graded, diamonds must be loose stones, because once a diamond is set into metal the metal can affect its color.

  • Diamonds are placed table-down, pavilion-up and viewed with a 10X loupe.

  • A lettering system from D to Z is used to identify the amount of color present in each diamond, with D awarded only to rare, totally colorless diamonds.

Diamond Color Grades

Colorless diamonds and diamonds that are yellow or yellowish brown are grouped into the categories shown below. These grades do not apply to fancy colored diamonds -- they have their own color grading standards.

D-E-F
Colorless.

G-H-I-J
Nearly colorless.

K-L-M
Faintly tinted, usually yellow.

N-O-P-Q-R
Lightly tinted, usually yellow. Tint can be seen with the naked eye.

S-T-U-V-W-X-Y-Z
Tinted, usually yellow, may progress to brownish. Tint visible to the naked eye, even when mounted.

Other Factors Can Affect Diamond Color

Fluorescence
GIA diamond reports and many other lab reports indicate whether or not a diamond exhibits fluorescence, which means the diamond's color changes when it is exposed to ultraviolet radiation. Since UV radiation is a component of daylight and is also present in fluorescent lit rooms, diamonds with this characteristic can appear to change color quite often.

  • Diamonds that produce a blue reaction usually appear whiter, or more colorless, under UV light.

  • Stones that fluoresce yellow appear even more yellow under some lighting conditions.

Diamond Color Treatments

The color of a some diamonds can be dramatically changed by using HPHT (high pressure/high temperature) processing. Unlike diamond treatments used in the past, HPHT changes appear to be permanent.

Coatings are sometimes used to temporarily enhance a diamond's color.

Settings that Enhance Diamond Color

A loose diamond that appears lightly yellow to the naked eye will usually appear more colorless when mounted in a white setting -- platinum or white-gold. Mounting the same diamond in yellow-gold metal usually enhances the diamond's yellowish tone.

Diamond Color, the Bottom Line

A diamond's color grade affects its price, but it isn't the most important diamond characteristic to consider before purchasing a diamond. If your budget prevents you from buying a D through F graded diamond it does not mean you cannot own a beautiful gemstone.

Diamond grades G through J can be fine gems, and other grades may be perfectly suitable. An experienced jeweler will help you evaluate and select the best diamond for your needs.

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