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.
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.
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.
No comments:
Post a Comment