Evaluating Diamond
Color
What exactly is diamond color? While most people think of the classic,
transparent diamond, which happens to be the most rare and valuable, the colors
of diamonds actually range from transparent all the way to a brownish
color. There are different saturations
of diamond color, and tones.
The Gemological Institute of America, known as the GIA for
short, is the most commonly used system for evaluating diamond color. They've created something known as the “GIA
Color Grade Scale”, and it has placed a grading system on the many different
colors and shades of diamonds, classifying into 22 letter grades.
How Diamonds are
Graded
The Gemological Institute of America has certified diamond
color grades as “master color comparison” diamonds. When a diamond is being graded, it is
compared against these master color comparison grades, to find the shades that
match it most closely. The diamond that
is being graded must be thoroughly cleaned and all oil must be removed from the
surface before being examined, since even small amounts of dirt or oils on the
surface of the diamond can alter the color.
A line of master color comparison diamonds or shade chart is
set up, with each grade placed about one inch apart, ranging from the lightest
and highest graded D shade, to the darkest, graded Z diamonds. The diamond color that is being graded is
moved from the left side of the comparison units to the right, until it matches
one of the shades.
Diamond grading should take place in a colorless
environment, using a balanced fluorescent light source that has a filtered,
cool white sun like ray. The room where
the grading takes place is dark, all except for the special grading light, in
order to obtain the most accurate grading of the diamond color.
Fluorescence of
Diamonds
Yet another consideration when considering the diamond color
is diamond fluorescence, and how it will effect the actual appearance in the
diamond color. Fluorescence causes some diamonds to change color when viewed in
our everyday, ultraviolet lighting, as well as under fluorescent light
bulbs.
When a diamond color is graded, the strength of the
fluorescence of that diamond must also be indicated. It may be considered to be strong, moderate,
or weak fluorescence, and the reports must also indicate what color the diamond
will change to due to the fluorescence.
The reason for this is when people are in the jewelry store, looking at
diamonds in the special lighting of the store, they may all appear to be the colorless,
transparent diamonds. When you purchase
a diamond and get it home under normal lighting, you could find your diamond is
yellowish in color!
You can ask your jeweler to provide grading documentation
and information about the fluorescent value of a particular diamond before
purchasing, to make sure that you will be happy with the diamond you buy. Many jewelers also can show you the diamond
under different lighting conditions, which will enable you to fully appreciate
the beauty of the diamond before you buy it.
Some individuals like a diamond color with a darker shade, while others
are insistent on the transparent diamond color.
The diamond color is one of personal preference, so be sure to do a
little research before making your final selection.
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