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 Post subject: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sat Dec 23, 2017 2:07 pm 
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First a little backround... My father bought this stone in the early 70's from a dealer in the old city of Jerusalem and had it set as a ring in a basket setting. He gave it to my mother who only wore it a few times before it chipped and had to be re-cut. The resulting 76ct stone was re-set as a pendent for safety and because my mother found it to large for her hand. I have recently inherited it and had it looked at and confirmed as Topaz. My question now is what color does it qualify as? Please let me know what you experienced folks think.
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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sat Dec 23, 2017 2:55 pm 
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Based on the pictures, if topaz I would call it imperial for sure. But it is an unusual one, and at that size it is well worth a full lab report.

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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sat Dec 23, 2017 3:13 pm 
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Thanks Stephen. One thing I left out is that at the time of purchase it was represented as "Russian Topaz" Can that be confirmed by a specific lab?


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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sat Dec 23, 2017 5:35 pm 
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Nobody does that as far as I know. Reallly this is because while inexpensove topaz varieties come from many locales, Brazil produces like 99% of fine topaz (imperial and pink). The Russian origin would be very puzzling. Russia produces two kinds of topaz, pegmatitic and very limited imperial. Pegmatitic topax can be large and orange-brown, but is almost always unstable in sunlight and has at the very least brown tones with the orange (usually really it is orange tones in the brown). Russia did produce a small amount of true imperial in the early 1800s (pink, orange and purple--the big difference is the presence of chromium, which only happens in topaz produced in a metamorphic environment) but production was pretty limited as I understand it and large stones were not abundant. If it is real imperial type chromium bearing topaz I would guess it must be Brazilian.

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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sat Dec 23, 2017 10:54 pm 
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But the one area in Russia that produced topaz may still have some limited finds. I would very much like to see a Raman Spectra of the specimen.


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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sun Dec 24, 2017 8:13 am 
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Here is a wonderful thread I started over on FMF forum, regarding the name "imperial", in regards to topaz. Had some heavy hitters chime in on it....Pete Modresky and Joel Arem....even the great Luiz Menezes, before he passed. I hadn't read it in a while, but I think it's got the best answers and explanation on the internet.


Luiz gives a great write-up for imperial topaz....

"Imperial topaz was found for the first time in Brazil in 1751, in the area of Ouro Preto (at that time it was still called "Villa Rica", that means "Rich Village", due to the gold deposits that were been exploited there), and was initially called "Brazilian ruby", until it was finally classified as topaz; but it was only in 1763 that this find was made public by the Portuguese kingdom.

There are 2 versions for the adoption of the name "imperial topaz": one is that the first Brazilian emperor, Pedro I, on the early 1830's travelled to the Ouro Preto area to deal with a rebellion against his ruling and was granted with some of these topaz; one of his close assistants, Jose Boniácio de Andrada e Silva, was a world-class mineralogist (andradite was named after him); the second version is that the name was suggested by Henrique Gorceix, a French mining geologist that was invited by the second Brazilian emperor, Pedro II, to found the first mining school in Brazil, at Ouro Preto, on the late 1870's; in 1881 Pedro II visited Ouro Preto and then Gorceix granted him a superb crystal of imperial topaz, and they decided to call it "imperial" to emphasize the difference between these genuine topaz from many other yellow gemstones (like citrine) that at that time were being also called "topaz".

At that time there was no Internet and no I.M.A., so it appears to me that both finds (at Ouro Preto and at Russia) occured at about the same time and both topaz were called "imperial" independentely, so I disagree with the assertion that the original "imperial topaz" are only those from Russia.

The several mines at Ouro Preto have produced very large amounts of imperial topaz for more than one century; even now very few pieces have been found in Pakistan and in Russia and the only other locality that has produced a little more (but even though much, much less than Ouro Preto) is located on the border between Zambia and Congo. So imperial topaz is typically a Brazilian stone.

I disagree that yellow and orange topaz from Ouro Preto cannot be called "imperial"; the name has been accepted by the mineral community for over one century for all shades of color (yellow, orange, reddish-orange, pink and purple); if the name is decided to be applied only for the reddish-orange topaz I think that the same criteria should be used on many other cases: pink rubelite should be down-graded to pink tourmaline, and "rubelite" should be used only for ruby-red tourmalines; greenish-blue indicolites should be down-graded to "greenish-blue tourmalines", and "indicolite" should only be used for indigo-blue tourmalines, and so on.

That is my opinion.

I would also call "imperial" the topaz crystals I have seen from the border of Zambia/Congo, not only for the color but also for the habit: long striated prismatic crystals with a simple pyramidal termination; therefore, I would not call "imperial" some yellow topaz crystals found in granitic pegmatites in Minas Gerais and Espirito Snto state that also produce aquamarine and heliodor; these topaz from pegmatitic origin are more equidimensional and never show striations on the prism faces; I would also not call "imperial" the topaz crystals from Thomas Range, Utah, neither the orange to peach-colored topaz found together with aquamarine, schorl, kunzite, garnet and pink apatite in granitic pegmatites elsewhere in Pakistan and Afganistan.

The imperial topaz from Ouro Preto are found in metamorphic carbonate rocks, as well as the reddish-pink ones (also prismatic striated, with simple pyramidal temination) from the Ghundao mountains, Pakistan; I don't know about the old ones from Russia and the new ones from Zambia/Congo, but I suppose that there might be a possibility that these prismatic striated topaz come only from metamorphic rocks, whilst the ones from pegmatites or rhyolites have flat prism faces, without striations; this guess is also supported by the Brumado locality, constituted of metamorphic magnesian carbonates where tiny prismtic striated topaz crystals are found, showing a very similar habit as the ones from Ouro Preto and Pakistan; the termination in Brumado is also a simple short pyramid.

I respect the opinion of Pete Modresky and Joel Arem, based on scientific consideration they are correct; but from the mineral dealer/ mineral collector point of view I think we should keep using the traditional and widely used names, on the way that everybody understand.

http://www.mineral-forum.com/message-bo ... rial#11082

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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sun Dec 24, 2017 10:40 am 
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In several hours of research I think I have found the closest (most similar in color and "character") stone to mine. What do you think of the ID?
https://www.litnon.com/index.php?page=viewgem&id=6334


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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sun Dec 24, 2017 3:04 pm 
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I have seen yellow-yellow orange topaz typically called "precious" and when a little pink gets into the mix so it moves toward salmon,then red/pink/ or (best of all in my opinion) purple, called imperial.


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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sun Dec 24, 2017 5:07 pm 
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If it is indeed topaz, I would call it orange or perhaps sherry topaz.


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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sun Dec 24, 2017 10:00 pm 
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Stephen Challener wrote:
Based on the pictures, if topaz I would call it imperial for sure. But it is an unusual one, and at that size it is well worth a full lab report.

Barbra Voltaire wrote:
If it is indeed topaz, I would call it orange or perhaps sherry topaz.


I am curious as to which characteristics make the ID on this stone difficult and unusual(not upset just curious). The person that ID'd it for me is an AGA senior gemologist with an accredited lab here in MA and he did a couple of double takes as well. He turned up the magnification on his scope (how far I don't know) and still worked to find an inclusion to go along with his testing before he'd believe it was real. As I said in another post a GIA appraiser with jewelry store equip. wouldn't even call it a "stone" so there must be something that imparts doubt can someone enlighten me as I am a COMPLETE layman?


Last edited by rogerg on Mon Dec 25, 2017 11:29 am, edited 1 time in total.

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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Sun Dec 24, 2017 10:06 pm 
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dchallener wrote:
But the one area in Russia that produced topaz may still have some limited finds. I would very much like to see a Raman Spectra of the specimen.


Can you please tell me what equipment is required to produce that test and what it would tell us? I read up on the process but couldn't quite relate to it. Thank youi!


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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Mon Dec 25, 2017 3:11 pm 
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Finally learned how to turn off the flash and got some natural light when home!
1st cloud covered natural light w/flash
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2nd same light no flash
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3rd after snow stopped and sun came out (indirect)
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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Mon Dec 25, 2017 4:12 pm 
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GIA wrote:
How do I know if a topaz is "Imperial topaz”?

There is no official standard for imperial topaz. Some dealers use the term for colors that are orange to pink to red to purple, others reserve the term for certain saturated shades. It’s the color, not the term “Imperial” that gives topaz its value.


IMO, the term "imperial" is just a merchandising gimmick.


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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Mon Dec 25, 2017 4:49 pm 
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Barbra Voltaire wrote:
GIA wrote:
How do I know if a topaz is "Imperial topaz”?

There is no official standard for imperial topaz. Some dealers use the term for colors that are orange to pink to red to purple, others reserve the term for certain saturated shades. It’s the color, not the term “Imperial” that gives topaz its value.


IMO, the term "imperial" is just a merchandising gimmick.

The more I read the more I tend to agree. That being said there must be a range of color that the marketplace sets corresponding value/desirability to. It seems that even varies by dealer and locale (there's that marketing thing again).
I come back to wondering under which light experts grade these stones or does that also depend on dealer, origin and locale?

I am also trying to decide if my specimen is best left as is, re-cut to a "fancier" cut or split into two smaller stones for his and hers rings. It seems that there are varied enough members here to give me sound advice as to how to "maximize" the stone.
Thanks to all and happy holidays!

Roger


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 Post subject: Re: Topaz... Imperial, Precious or Golden Orange?
PostPosted: Mon Dec 25, 2017 4:57 pm 
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I would re-cut your gem to improve the light return. I think it would make a world of difference in accentuating the color(s).


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