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AGS Labs Changes Fluorescence Nomenclature

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pricescope

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DECEMBER 10, 2002 - LAS VEGAS -- As of Jan. 1, all American Gem Society Laboratories (AGSL) diamond grading reports will contain updated wording to describe the gem's fluorescence.

The "inert" and "faint" fluorescence descriptors will be combined into a single descriptor, "negligible," which is commonly defined as "not significant or important enough to be worth considering."

The current AGSL fluorescence nomenclature includes five descriptors: "inert," "faint," "medium," "strong" and "very strong." The last three are followed by the color of the fluorescence, which is usually blue in diamond but may also be yellow, orange, red and white.

"Since the appearance of a diamond that is truly inert or exhibits 'faint' fluorescence is not adversely affected in any way, the descriptor 'negligible' is more accurate and more appropriate," said AGSL Director Peter Yantzer. "We feel that this is a very positive and dynamic change."[/u]
 

fire&ice

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Thanks Leonid,

...but I have to ask "What is White fluorescense?"
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
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Aug 15, 2000
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White = white, it can be cloudy milky white, but is incredibly rare.

I have been thinking about this AGS move and can not see any problem with it.

The more troubling isue is Marty Haske's assertion that GIA are color grading with tubes that give fluoro blue stones a big assistance resulting in higher grades.
 

mike04456

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The more troubling isue is Marty Haske's assertion that GIA are color grading with tubes that give fluoro blue stones a big assistance resulting in higher grades.
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Haske's objection is based on a one-line change in GIA's Diamonds course. The course materials and the diamond grading take place in two different parts of GIA, parts that have historically been at odds on a number of issues. One example is the old Make Grade system, that was taught for decades in the correspondence courses but never adopted by the Gem Trade Lab. So the fact that the courses say one thing doesn't mean the Lab has changed the way it grades diamonds. I'm sure we'll hear more about this, but I don't see a cause for panic.
 
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