Sunday, July 10, 2011

How to examine and evaluate diamond's color?

Color is one of the four key factors that influence the final price of the diamond, together with cut, clarity, and carat. Though to many this may seem like very easy thing to do, examining diamond color is very difficult, and it more often than not requires professional knowledge and skill. Here is how the professionals usually do this.

First of all make sure to examine the color of diamond under the normal lightning. Professionals usually use fluorescent bulbs that produce neutral-light color, because if diamond color is examined under warmer or colder light the results can often look quite opposite, warmer light usually gives diamond red and yellow hues, while colder light gives diamond blue hues.

Together with light under which diamond color is examined there is also one other factor almost equally important, namely our eyes. Our eyes are extremely sensitive and so in order for our eyes to do the most objective work we must give them some time to get use to the light in the stone's surface. When examining color it is also important that we are not feeling tired or sleepy because this can sometimes significantly affect the outcome, even mood is important factor because certain tests have showed that being in bad mood can neutralize the influence of bright colors in the examination area.

When professional gemologist examines the diamond he places it with the table's faced down with the angle of sight parallel to the rondist and vertical to the pavilion. When examining diamond gemologist pays special attention to the amount of color and the saturation scale in the diamond. Gemologists must also pay attention to any possible flaws when determining the color because flaws can cause a different shade to the diamond, therefore causing erroneous color reading.

Examining diamond color usually needs several different tests. It also has to be said that GIA created a standard diamond color guideline under which the color of each diamond is compared to a pre-selected set of control stones.

The final step in color evaluation is giving a letter grade to the diamond. Letter grade system starts at the letter D and goes to Z with a color for each letter. The lettered list is as follows.
- D-E-F: colorless
- G-H-I-J: nearly colorless
- K-L-M: slightly colored, often yellow
- N-O-P-Q-R: somewhat colored, often yellow
- S-T-U-V-W-X-Y-Z: colored, usually yellow, and sometimes brown.


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