Color grading fancy-colored diamonds is a complex process of assessing the color of a diamond in three dimensions: hue (the aspect that gives the color its name - like red, green, or blue), tone (the lightness to darkness of the color) and saturation (the strength or purity of the color). Diamond professionals determine color grades grades by comparing diamonds side-by-side in a controlled lighting and viewing environment.
The diamond industry recognizes 27 hues for color grading diamonds. This places a practical limit on the number of possible color descriptions and creates terminology that’s precise enough for worlds leading gem laboratory, but accessible and understandable by the public.
Each of the 27 hues represents a range of colors. The 27-hues consist of basic colors like red, blue, and green, and mixed colors like orangy red, green-blue, and greenish yellow. When grading fancy-colored diamonds, the predominant hue is stated last.
The classification pertaining to the depth of color is extremely important. One tonal difference can dramatically affect value. But you must also understand that the terminology and gradations used to indicate the depth of color – the tonal scale – is not the same for every color. If you are seeking a yellow diamond, for example, and decide you want a color that is darker in tone than “Fancy yellow,” the next classification would be “Intense”; you would be wasting your time searching for anything between “Fancy yellow” and “Fancy Intense” because in yellow diamonds there are no classifications between the two. On the other hand, if you are looking at brownish yellow diamonds, there is a “Deep” classification that is darker than “Fancy brownish-yellow” but more affordable than “Intense.” In blue diamonds, you will also find a “Deep” classification.
To accurately evaluate rarity and value, and to be sure you have found the depth of color that best suits your needs, you must be sure to find out what the specific tonal classifications are for the particular color you are considering.
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