Curious about colour grades

[hihowareyou]

Since I started my diamond hunt earlier this year one question has remained unanswered. It isn''t important but is driving me crazy not knowing

Why does the grading scale start at D instead of A. It goes from D-Z but there is no A,B or C.

Does anyone know why?

 

[Lestat]

"Before GIA developed the D-Z Color Grading Scale, a variety of other systems were loosely applied. These included letters of the alphabet (A, B and C, with multiple A’s for the best stones), Arabic (0, 1, 2, 3) and Roman (I, II, III) numerals, and descriptions such as “gem blue” or “blue white.” The result of all these grading systems was inconsistency and inaccuracy. Because the creators of the GIA Color Scale wanted to start fresh, without any association with earlier systems, they chose to start with the letter D—a letter grade normally not associated with top quality."

Source: GIA website

 

[Lorelei]

Date: 10/5/2009 3:56:06 AM
Author:hihowareyou
Since I started my diamond hunt earlier this year one question has remained unanswered. It isn't important but is driving me crazy not knowing

Why does the grading scale start at D instead of A. It goes from D-Z but there is no A,B or C.

Does anyone know why?

This is quoted from the link on colour grading here - " Trivia: When GIA developed the D-Z grading system they avoided A-C because some dealers use A1 to C3 for 'in-house' grading systems. There will never be better color than D!"

A theory I have heard, when colour grading began, ABC weren't used in case D colour grade was surpassed, to this day it has not.

 

[hihowareyou]

doh, I didn''t think it would have been included in the guides on here.

I find it very interesting but those reasons seem to make perfect sense.

Thanks for the info

 

[Lorelei]

Date: 10/5/2009 5:16:46 AM
Author: hihowareyou
doh, I didn''t think it would have been included in the guides on here.

I find it very interesting but those reasons seem to make perfect sense.

Thanks for the info

Glad to help! Sometimes things are right under your nose, so don''t feel bad!!