How to Grade Diamond Rings
Diamonds are one of the most valuable gems in the world. They are judged based on color, clarity, cut and carat weight. These categories of measurements are also known as the Four Cs. The Four Cs ultimately determine a diamond's total value. A diamond's grade is based on its color. The most common misconception of diamonds is that they are colorless. All diamonds have color. But it is the mistakenly colorless or white diamond that all other diamonds are graded against. The Gemological Institute of America (GIA) has devised a set of guidelines on which to grade a diamond's color. Does this Spark an idea?
Instructions
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Grade loose diamonds. To be graded, a diamond must be loose. Once it is set in metal, the metal affects the color, which can throw off the grade.
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Set the loose diamond on a table. The diamond must be placed table-side down and pavilion-side up. The table-side is the flat surface end of the diamond, versus the pavilion-side, which is the pointy end or tip of the diamond.
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Look at the diamond through a loupe. Diamonds must be viewed through a 10x loupe. A loupe is a special magnifying glass for looking at gems. The loupe allows surface blemishes and internal flaws to be more visible. It also makes the diamond's color more visible.
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Grade the diamond based on the color. A lettering system from D to Z is used to specify how much color is present in a diamond. The letter D is only used for the most rare diamonds.
Each grade beyond D can affect the price by 10% to 15% less than the grade above it.
The lettering system is as follows:
D-E-F
Colorless.G-H-I-J
Nearly colorless. Usually very white and bright.K-L-M
Faintly tinted, usually yellow in color.N-O-P-Q-R
Lightly tinted, usually yellow in color. This coloring can be viewed with the naked eye.S-T-U-V-W-X-Y-Z
Tinted and usually yellow in color. The color may progress to a brownish tint. This coloring is visible to the naked eye and doesn't change when mounted.
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