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David Or Neal? Why Do Fancy Shapes (Pear & Marquise) Sometimes Hold More Color In The Tip?


ronk15a
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I'm surprised either of you gentleman (David or Neil) didn't respond to the original post. Im thinking the question was either dumb, or just simply objectively inaccurate. I'll try again!

 

 

Dear community,

 

I recently submitted a 2.53ct. Pear to GIA. The stone appeared to be G-H in the body, and J at the tip. What is your opinion on the cause of this? Is it color distribution/evenness, symmetry, overall cut quality, faceting?

 

Your thoughts are greatly appreciated.

 

Regards Ron

Edited by ronk15a
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I read every response you gave, and I appreciate them all. Why would you say I have not listened. As you know every response is taken with a grain of salt like all information except for 2 + 2=4. In regards to HPHT, what if (anything) does that have to do with Pears & Marquise appearing to have optical characteristics that are not even in color????

 

BTW: I was not asking about: HPHT grading (I was aking about HPHT & CVD identifying).

 

 

Regards Ron

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I took out a cape/off colored pear from my inventory and examined the stone for its color concentration. The stone appears to be an M-N in color when viewed table down. The response I received from George seems to be the most accurate. Thank you George!!

 

I see that on a pear shape the tip has the most concentration of facets; then the opposite side of the stone, and then the area in then middle. When viewed face-up color goes from darkest to lightest in color, based on most concentration of facets to least. I find that when viewed table down as naturally done, the same exists just a little less intense. That’s why my original question was…..

 

Dear community,

 

I recently submitted a 2.53ct. Pear to GIA. The stone appeared to be G-H in the body and J at the tip. What is your opinion on the cause of this, as well as how GIA considers these stones in regards to their color?

 

I believe that the stone will come back an I color. For the reason being the combination; (body and tip) should equal overall color grade. Your thoughts are greatly appreciated.

 

Regards Ron

 

This follows George’s notion that overall facet concentration has a direct effect on optical appearance. Jan as far as your response is concerned; Yes I know that all stones are graded table down; however it should be stated that P & M’s in the cape series/ K-L-M-N seem to have more concentration of color optically in the tip, then any other place on the stone. Community, your thoughts?

Edited by ronk15a
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Dear David,

 

Thank you for your quick reply! So would you say that when looking at a pear shape, that is not colorless, G+ table down of course, what area on the stone should provide the best conclusion to GIA color grade. Would you say tip conservatively speaking? Thanks again!

 

Regards Ron

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Dear Neil,

When I say Tip, I’m referring to looking at the pear through the side, at the tip. Not; end to end like you just alluded too in the previous post. By the way I bought the diamond dock, and returned it because it was not worth the money.....a white business card and (2) 15w daylight fluorescents work just fine.

Based on your notion that GIA’s grading methodology is examined (table down at its thickest point) is it accurate to say that the tip is irrelevant when considering color; considering that the thickest part of the pear when viewed from the side table down is culet-center-middle-table?

Regards Ron

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I don't use a diamond dock either, for the same reason. I'm just answering your question about the official methodology. You look through the thickest part of the stone through the side (obviously tip to tip would be thicker, which is why I mentoned that).

 

The diamond dock does have a point. It controls the lighting AROUND where you're grading and often gemologists forget that. The color of the room walls and ceiling really do have an affect as does the spectra of the light bulbs you're using. The DD standardizes that.

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Dear Neil,

When I say Tip, I’m referring to looking at the pear through the side, at the tip. Not; end to end like you just alluded too in the previous post. By the way I bought the diamond dock, and returned it because it was not worth the money.....a white business card and (2) 15w daylight fluorescents work just fine.

Based on your notion that GIA’s grading methodology is examined (table down at its thickest point) is it accurate to say that the tip is irrelevant when considering color; considering that the thickest part of the pear when viewed from the side table down is culet-center-middle-table?

Regards Ron

 

How much of a difference in color are you noticing in the different areas of the body to cause such a concern?

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yes you are absolutely correct, the dd controls the lighting environment to a neutral color. but i agree; i was dis-satisfied with the unit as a whole. getting back to pears, tips, and color. i don't understand your response. is-int the thickest part of pear when table down, side view, is: culet-center-middle-table?

 

does this mean you do not look at the tip for color grading, in terms of GIA conclusion. im still trying to answer this question....which nobody seems to want to answer directly.

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yes you are absolutely correct, the dd controls the lighting environment to a neutral color. but i agree; i was dis-satisfied with the unit as a whole. getting back to pears, tips, and color. i don't understand your response. is-int the thickest part of pear when table down, side view, is: culet-center-middle-table?

 

does this mean you do not look at the tip for color grading, in terms of GIA conclusion. im still trying to answer this question....which nobody seems to want to answer directly.

 

I don't know how more direct you want it to be...

 

GIA color grading methodology is to look at the stone table down through the thickest part of the stone viewing through the side (not end to end) with a white background and a neutral surrounding environment (ie. in a diamond dock).

 

If the tip of the pear or marquise is really significantly darker (not from the top - through the side), I don't know what GIA would do, but I have never seen a (near) colourless stone where the colour is detectably non-uniform. Fancy colours yes - and this is why GIA would grade it the same way methodologically, but call it "uneven distribution".

Edited by davidelevi
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