How does GIA grade diamond color? Everything you need to know.

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Diamonds are graded un set and upside down in a controlled lighting environment and against a set of master stones.

Diamond Color Scale and Chart Guide

Are you shopping for a diamond? Trying to figure out which diamond color is best? Check out this diamond color guide.

www.pricescope.com

This link contains everything you need to know about diamond color grading.

 

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Clarify: this link speaks to several diamond graders, not just GIA.

from the link:

Sub-par cut quality can also cause a diamond to show more color face-up than its lab grade, as we will illustrate below. There is an enormous range of appearance for diamonds of any single color grade, based on the variables.

• Diamond color grading is a subjective judgment
• Standards also vary, so diamonds graded G or H color in a chain store might be judged J color from GIA or AGS
• Cut quality influences everything: Light escaping through the pavilion or bouncing around inside the diamond illuminates body tone
• Diamonds with sub-par cut quality can even face-up with more color than their laboratory grade
• Diamond fluorescence can also influence color, as we will cover below

also

1. Diamond appearance can also be influenced by the color temperature of lighting. Normal daylight has a color temperature near 5000K. “White” indoor lighting has a color temperature between 3500K-4500K. Lighting at lower Kelvin temperatures (2700K-3000K) emits yellow light and lighting at higher Kelvin temperatures emits bluer light. When shopping in jewelry showrooms be aware that the store’s lighting could be designed at high Kelvin temperatures to reduce the appearance of yellow tint.

For these reasons, diamonds are professionally assessed in neutrally-colored environments by graders wearing white tops, seen under diffused light sources with white color temperatures.

And



In well-cut diamonds light gets in and out on shorter ray-paths with greater intensity. This can cause the appearance of less color when the diamond is seen from the top.

Diamond color chart: Color reduction

Top cut quality can help diamonds appear more colorless: Cut focused brands like A CUT ABOVE® from Whiteflash have been reported to benefit from face-up color reduction in PriceScope testimonials.

Alternately, if the diamond is cut so that light escapes through the bottom – or bounces around inside – the color within that diamond may be exaggerated when seen from the top.

Diamond color chart: Color exaggeration

this is a very thorough explanation of color— so much more at the link.

 

[mx5_dvr]

I guess K color is all we need.

 

[sledge]

Nice share. Did you write or help write this?

 

[SomethingNew]

So does OEC show more color than MRB? Assuming both well cut (though not ACA, maybe a well cut OEC vs a triple x).

 

[Rfisher]

TBH I’m missing the fanfic though.

 

[whitewave]

Nice share. Did you write or help write this?

No, and I don’t meant to sound like I did! I don’t know who wrote it TBH.

 

[John Pollard]

No, and I don’t meant to sound like I did! I don’t know who wrote it TBH.

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[LLJsmom]

So does OEC show more color than MRB? Assuming both well cut (though not ACA, maybe a well cut OEC vs a triple x).

This is a much discussed topic. Maybe you can post a separate thread and let people answer. You'll get more people to see your question if you create another thread rather than it getting buried here in how GIA grades color.

 

[SomethingNew]

This is a much discussed topic. Maybe you can post a separate thread and let people answer. You'll get more people to see your question if you create another thread rather than it getting buried here in how GIA grades color.

yes thank you Karl for posting this, super helpful!

oec vs ideal cut color.

This was asked in another thread. A well cut oec holds up well with ideal cuts and better than gia ex steep/deeps at not showing color for the same color rough. This is mainly that the lower half/girdle facets angle under the table causes much of the color enhancement in a steep deep mrb, where...

www.pricescope.com