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The Diamond Specialists
 

DIAMOND COLOR EDUCATION

GIA Color Grading Scale

1. The vast majority of diamonds may be placed on a scale that ranges from colorless to tinges of yellow, brown, or gray. Colorless diamonds are more rare and more valuable than diamonds with tinges of these colors.

2. The GIA (Gemological Institute of America) color grading scale designates colorless diamonds with the letter "D" with yellower stones lower in the alphabet.

3. GIA itself states that the average consumer would probably not see any differences in the first seven GIA color grades (D through J color) if the diamond were mounted and viewed from the top.

4. Loose diamonds can be more accurately graded when viewed under ideal conditions (a dull white background with a filtered fluorescent light source).

5. Almost unnoticeable differences in color between two stones can make a difference in the value of hundreds or even thousands of dollars.

Diamond Color and its Effect on Value
There are several diamond price sheets that appraisers throughout the nation consult to estimate the wholesale value for diamonds. The Rapaport Diamond Report is likely the most widely used.

1. A well cut and strictly graded 1 ct. "D" color and "Internally Flawless" diamond would wholesale for about $18,100-per ct.

2. A well cut and strictly graded 1 ct. "I" color and "Internally Flawless" diamond would wholesale for about $6,500-per ct.

3. The price difference of $11,600 per carat is based entirely on the 5 grade difference in the color of the two stones.

Diamond Fluorescence

GIA Fluorescence Grading Scale
1. Diamond fluorescence is technically speaking: the emission of energy in the form of light by a diamond as a result of its simultaneously absorbing radiation of another wavelength. The electrons of some diamonds are excited by the radiation and emit the excess energy in returning to their original state.

2. This emission, unlike phosphorescence, ceases as soon as the source of excitation is removed, and so the glow disappears when removed from an ultra-violet light source.

3. Fluorescence is a naturally occurring phenomenon in diamonds and other gemstones. If it is present in a diamond, it cannot be removed and if a diamond does not fluoresce, it cannot be induced into the stone. The fluorescence that occurs in a diamond arises from submicroscopic structures within the diamond when it is exposed to invisible UV light.

4. Blue is the most common color of fluorescence, but other colors are also possible.

Diamond Fluorescence and its Effect on Value
1. Diamond fluorescence in colors other than blue can have a very negative impact on value. That is because fluorescence in these colors will make the color of a diamond appear to be darker or more yellow than it really is under light that includes ultraviolet radiation.

2. Knowledgeable diamond dealers will discount the value of these stones by up to 50%.

3. Blue fluorescence can have both positive and negative effects on both the appearance of a diamond and its value.

4. "Faint Blue" or "Medium Blue" fluorescence can enhance the apparent color of a diamond under many lighting conditions, making it look whiter than it really is. There is no premium for these diamonds.

5. On the other hand, diamonds with "Strong Blue" or "Very Strong Blue" fluorescence can appear "milky" or "cloudy" in these lighting conditions. The value of the later diamonds can be discounted by the trade by 15% to 50%.