Colorless and
near-colorless diamonds (grades D to J) are the most highly valued
and command the highest prices. Diamonds may also have a slight tint of color,
generally yellow to brown, but other colors are seen occasionally. Color in a
diamond is caused by trace elements, usually nitrogen that is trapped in the
diamond's internal atomic framework. To determine a diamond's Color
grade under non-laboratory conditions is very difficult, even for an expert.
Most people can easily see the differences in color if they compare two diamonds
with color grades that are at least two or three Color grades apart. To
help you select the most brilliant diamond, we only offer diamonds with the best
grades of color (grades F to H). Diamonds with D and E color
grades are available by special order.
The Gemological Institute
of America (GIA) and the American Gem Society (AGS)have devised the following color grading scale for diamonds:
The Z+ or FANCY
grade refers to those exceedingly rare diamonds that are deeply colored. These
deeply colored diamonds are usually canary yellow, but red, pink, blue and green
are also seen. Additional criteria, such as Fluorescence, Hue and Color
Saturation, are also utilized to determine the Color grade of Fancy
diamonds. Some of the world's most famous diamonds include the Hope Diamond
(deep blue) and the Dresden Green Diamond (deep green) are Fancy
diamonds. Light yellow to light brown or "champagne" colored
diamonds are occasionally offered for sale as
Fancy diamonds. These light brown or "champagne" colors are not considered
to be in the Z+ grade by the GIA.
Fluorescence: Diamonds have the
ability to fluoresce under ultraviolet (UV) light. Natural sun light contains
some UV light, but it is not enough to detect fluorescence. Some diamonds will
emit a distinctive blue glow when exposed to UV light, although other colors
occasionally occur. Fluorescence is graded by intensity and is classified as
None, Faint, Medium, Strong and Very Strong. Fluorescence only becomes an issue
when evaluating Colorless (D, E and F grades) and Fancy (Z+)
diamonds.
T he
Key Point to Remember: For Color
Grades, the closer the letter is to D, the better.
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Gold Jewelry
