Introduction to Colored Diamonds and Color Grading of Diamonds
The color grading of diamonds is one of the important 4 c’s that forms the basic foundation for diamond grading and evaluation.
Here, when we talk of diamond color grading we are referring to the color grading of white and yellow diamonds and not color grading of the popular fancy diamonds such as blue diamonds. Most of the gem quality diamonds are white to yellow and usually ranging from colourless to slightly tinted yellow.
Diamonds come in different colors, such as pink, green and blue. These are known as fancy diamonds or colored diamonds. One of the factors for determining the price of a colored diamond is the rareity of the color. The rarer the color the higher the price.
One must note that the color of a diamond is as a result of the composition, and will be explained in another comprehensive article ” The causes of color in diamonds”. The color of a diamond does not change over time. This article will focus on the color grading of white and yellow diamonds.
An example of a master set used by gemmologists to determine the color grade of white diamonds.
Colourless diamonds allow more light to pass through it than a colored diamond. Therefore colourless diamonds emit more sparkle and fire.
Although many diamonds may appear colourless, only a few are truly colorless. Many white diamonds may have subtle yellow or brown tones that can only be detected when comparing diamonds side by side. Therefore the more colorless a diamond the greater the value. However please note that this rule is true only for white to slightly tinted yellow diamonds. Fancy diamonds on the other hand are much more expensive because of the rarerity of their color eg. Blue Diamonds.
The Gemological Institute of America (GIA) has developed a professional color scale to grade ‘whiteness’ or ‘colorlessness’. The scale starts with D (The highest grade for colorlessness) and continues all the way to Z. As the grades go down the alphabet there is a gradual increase in the traces of light yellow or brownish color (See the image above).
It is important to note that diamonds graded from G to I will appear colorless to the untrained eye.
The illustrastion above shows how to view a diamond to determine its color grade.
The color grade of a diamond should be determined by placing it upside down on a white paper grading trough (From the bottom of the stone- See illustration above).
If a diamond is viewed from the top of the stone (Face up position), the brilliance and dispersion of the stone is very high making it impossible to determine the color grading accurately.
To determine the exact color grade of a diamond a set of master calibrated diamonds to the exact grade are compared with the diamond. The comparism is done in a standard viewing box with the master stones placed on either side of the diammond. This is the most accurate method for grading the color of diamonds.
Some Important Facts to Consider when Purchasing Diamonds- Regarding the Color Grading of Diamonds;
i) It is important to note that diamonds graded from G to I will appear colorless to the untrained eye.
ii) A diamond of higher color grade looks much better in a platinum or white gold setting. If you want to set the diamond in gold, you have the option of going for a cheaper diamond with a lower color grade and which would also equally look good after setting.
iii) Some people prefer the lower color grade diamonds because it gives a warmer glow.
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