some questions

[nerotic]

Reading on gubelin about their standards for determining a ruby, I had some doubts about a gem that I am particularly fond of, it is a Mozambique pigeon blood but without fluorescence and therefore I would like to understand if this is an added value or a defect

 

[Autumn in New England]

Hello there! The stone appears to have superb clarity, wow. The color is good... not purple or pink... very red, if a little warm, with maybe a touch of orange. It is a bit "garnet-like" in that the tone is darker. Great size! Decent cut for a ruby. About the fluorescence - in general, the stronger, the better. So while I wouldn't say a lack thereof is a "defect," it certainly affects the value. If you love this stone, as you said, I see absolutely nothing "wrong" with it. It's quite a nice ruby, IMO.

 

[nerotic]

thank you this is the assembled photo… it gets a lot of light and the diamond ring wasn't expensive

 

[Autumn in New England]

Oh you already own it! And set it!! How wonderful... big congrats. I love that sort of chunky "pinwheel" diamond halo. Enjoy.

 

[LilAlex]

Beautiful gem and ring!

Am I mistaken or are they not calling it pigeon-blood red?



Is it just reminiscent of that archetype? Very cagey wording there...would help to know if GRS "requires" the fluor for that descriptor. Usually these things says "this is" or "this has the qualities of," but not "You know what this reminds me of...?!" Not sure you could sell it as such.

 

[Autumn in New England]

Beautiful gem and ring!

Am I mistaken or are they not calling it pigeon-blood red?



Is it just reminiscent of that archetype? Very cagey wording there...would help to know if GRS "requires" the fluor for that descriptor. Usually these things says "this is" or "this has the qualities of," but not "You know what this reminds me of...?!" Not sure you could sell it as such.

My interpretation is that they reserve the pigeon's blood designation for vivid red rubies that have strong fluorescence. But if they observe a stone that has vivid red color without the fluorescence, they'll simply say... this flowery thing.

 

[VividRed]

It’s a very nice ruby, typical color for Mozambique material except for the smaller rough from a mine that used to produce fluorescent material (hard to find today). A tad on the dark side, AGL would probably give it a 3/80, which is very good to excellent.

I prefer Burmese rubies with a hint of purple or pink and fluorescence, but this is a solid choice

 

[nerotic]

Beautiful gem and ring!

Am I mistaken or are they not calling it pigeon-blood red?



Is it just reminiscent of that archetype? Very cagey wording there...would help to know if GRS "requires" the fluor for that descriptor. Usually these things says "this is" or "this has the qualities of," but not "You know what this reminds me of...?!" Not sure you could sell it as such.

so is it pigeon blood or not?

 

[Saphir]

Fluorescence can be removed during heat threatment.

 

[VividRed]

so is it pigeon blood or not?

Pigeon blood doesn’t mean anything, really. If I had to give my definition, it would be a vivid red ruby of medium dark tone with lots of chromium, some silk, and little to no iron.

Yours is a vivid red ruby without fluorescence, with darker tone than “medium-dark”, and no silk. In my book, not pigeon blood, then again I opened saying it doesn’t mean anything

 

[nerotic]

I looked around a lot in search of a nice ruby but as soon as I looked at other names the prices became crazy for me... I liked the color, the price excited me, I think it's the right one and so I bought it

 

[mellowyellowgirl]

It’s beautiful! Would love to see more photos of it!

 

[VividRed]

I looked around a lot in search of a nice ruby but as soon as I looked at other names the prices became crazy for me... I liked the color, the price excited me, I think it's the right one and so I bought it

It’s a very nice ruby, enjoy it!

 

[Autumn in New England]

Fluorescence can be removed during heat threatment.

I never considered that! But it certainly makes sense since heating causes structural changes. Interesting!!

 

[VividRed]

Fluorescence can be removed during heat threatment.

Ehm…are you sure? If there is a lot of iron already, very high temperature heating (almost melting) can cause the iron to redistribute within the crystal lattice, further reducing fluorescence under a UV lamp. But such rubies don’t fluoresce much in the first place, so you wouldn’t notice any meaningful visual difference - you would need a spectrometer to measure the change in UV reaction; and it would be tiny (from very low to “a bit less than very low”).

Anyway, I don’t think this ruby was given the “pseudo” PB rating because of fluorescence loss during heating.

Unless you know something I don’t, of course

Edited to add: if you have any reference to back up your statement I would be very interested in learning more about it

 

[nerotic]

Wouldn't it work on diamonds?

 

[Autumn in New England]

Ehm…are you sure? If there is a lot of iron already, very high temperature heating (almost melting) can cause the iron to redistribute within the crystal lattice, further reducing fluorescence under a UV lamp. But such rubies don’t fluoresce much in the first place, so you wouldn’t notice any meaningful visual difference - you would need a spectrometer to measure the change in UV reaction; and it would be tiny (from very low to “a bit less than very low”).

Anyway, I don’t think this ruby was given the “pseudo” PB rating because of fluorescence loss during heating.

Unless you know something I don’t, of course

Edited to add: if you have any reference to back up your statement I would be very interested in learning more about it

So when I initially saw @Saphir's post, I did a quick google search to confirm. The AI summary said yes, heat can cause a loss of fluorescence in rubies, and I didn't research it further. But your post made me curious, so I did a deeper dive just now. From what I can gather, low-temp heating does not affect the level of fluorescence in rubies (it can create a chalky look to it, however). But fluorescent bands can be destroyed by high temp heat treatment, especially those around 1500°C. I think extreme temps like that are only reserved for healing fractures and glass filling though? In any event, these statements are both per the GIA.

Low heat

High heat

 

[VividRed]

So when I initially saw @Saphir's post, I did a quick google search to confirm. The AI summary said yes, heat can cause a loss of fluorescence in rubies, and I didn't research it further. But your post made me curious, so I did a deeper dive just now. From what I can gather, low-temp heating does not affect the level of fluorescence in rubies (it can create a chalky look to it, however). But fluorescent bands can be destroyed by high temp heat treatment, especially those around 1500°C. I think extreme temps like that are only reserved for healing fractures and glass filling though? In any event, these statements are both per the GIA.

Low heat

High heat

Thank you, very interesting. I wish they would explain more though, it remains surface level. I will look into it

 

[Autumn in New England]

Thank you, very interesting. I wish they would explain more though, it remains surface level. I will look into it

Me too. I'm also wondering if origin/host rock/iron content plays a part, as you alluded to earlier.

 

[Enhoerning]

I don't think I've ever come across a heated ruby that was noticeably less fluorescent than I would have expected from an unheated specimen of the same geographic origin and color type. But that's just my personal observation, and it doesn't mean the phenomenon doesn't exist.

Regarding the GRS report and the iconic “without strong fluorescence” comment –

This comes up a lot when I'm advising clients on choosing a ruby. I’d like to state for the record that the comment does not mean the ruby has no fluorescence. That would be extremely rare, since virtually all rubies show some kind of fluorescent response to SW/LW UV. It simply means the stone lacks the strong fluorescence required to qualify as “pigeon blood” under GRS’ definition. While GRS may be the only lab that spells it out so explicitly in an appendix sheet, many players in the industry (including several other labs...) base their definition of “pigeon blood red” on strong fluorescence – so this is not unusual at all.

 

[nerotic]

so when GRS is named PIGEON BLOOD I will find this nomenclature in the color entry on the first page right?

 

[VividRed]

so when GRS is named PIGEON BLOOD I will find this nomenclature in the color entry on the first page right?

Yes, correct. Note that GRS is fairly generous in giving out this color grade, hence my first comment on it being meaningless. Some labs are stricter (SSEF and Gübelin) but there is not universally accepted definition of the color.

One thing they all seem to agree on is that it needs to fluoresce strongly. Yours doesn’t, so it doesn’t get the label. But it has nice body color, a tad darker than trade ideal, still a very solid red.

 

[nerotic]

Thanks

 

[Enhoerning]

so when GRS is named PIGEON BLOOD I will find this nomenclature in the color entry on the first page right?

Yes, correct. Note that GRS is fairly generous in giving out this color grade, hence my first comment on it being meaningless. Some labs are stricter (SSEF and Gübelin) but there is not universally accepted definition of the color.

One thing they all seem to agree on is that it needs to fluoresce strongly. Yours doesn’t, so it doesn’t get the label. But it has nice body color, a tad darker than trade ideal, still a very solid red.

GRS’s use of the term “pigeon blood” usually becomes clearer once people understand that, for GRS, it is a color-type descriptor – whereas for other labs (such as GIA, Gübelin, and SSEF) it functions more like an honor badge awarded to only a very small number of stones.

That being said, I don’t think GRS is particularly generous with “first-page pigeon blood” for Mozambique rubies (and I believe that’s what OP was asking about). Quite the contrary…which is why some people fetishize that particular grade.