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Peter
Joined: 16 Jan 2009
Posts: 346
Location: Sweden / Luxembourg
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Posted: Apr 11, 2010 03:03 Post subject: Re: Imperial topaz..whats in a name |
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Indigolite is indigo blue tourmaline (elbaite most commonly)
Heliodor was "sun colored" beryl, now it beats why we would have needed this term when we already had golden beryl, but it is now widely used and accepted. In Finland one pegmatite produced some incredible gem quality green beryls and among them were some ture golden beryls or heliodores. I have preferred to use the term green beryl, as that was the color of the majority of crystals. In Volodarsk, Ukraine most bery crystals are yellowish/green and more rarelt pure green or pure golden heliodore, and in some cases also depending on light.
I agree with Luiz that the new african topaz shoule also be labeled Imperial. The color beeing the original criteria but from mineralogical and geological point of view of course the morphology and genesis. Most of the old Ural ones were found as noted in alluvial deposits but they are found in narrow quartzveins. A recent russian book "Russkaja Brazilia" Russian Brazil describes mineral deposits in this region of the Urals with photographs form the field, pits and the cover showing some newly found "Imperial topaz" crystals from the Urals in a suite of colors and nuances.
The irradiated Pakistani topaz crystals originally from pegmatites has nothing to do with Imperial topaz, Indeed they can attain a "synthetic" deep brown to orange color upon irradiation, |
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Tenney Naumer
Joined: 12 Apr 2010
Posts: 10
Location: Marion, Illinois
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Posted: Apr 12, 2010 08:58 Post subject: Re: Imperial topaz..whats in a name |
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Hi everybody! I thought I would stop by to mention that I am originally from Illinois, although I have lived in Brazil for the past 12 years. _________________ Blog: "Gemstone News and Local Color from Teófilo Otoni" |
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Tenney Naumer
Joined: 12 Apr 2010
Posts: 10
Location: Marion, Illinois
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Posted: Apr 12, 2010 09:08 Post subject: Heliodor, golden beryl, green beryl, chrysoberyl |
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Peter wrote: | Heliodor was "sun colored" beryl, now it beats why we would have needed this term when we already had golden beryl, but it is now widely used and accepted. In Finland one pegmatite produced some incredible gem quality green beryls and among them were some ture golden beryls or heliodores. I have preferred to use the term green beryl, as that was the color of the majority of crystals. In Volodarsk, Ukraine most bery crystals are yellowish/green and more rarelt pure green or pure golden heliodore, and in some cases also depending on light. |
I admit to having been thoroughly confused about the various yellow and green beryls found near where I live in Brazil.
There is a mine not far away in Itambé, Bahia, that used to be famous for its aquarmarines back in the 1970s. Nowadays, the color is considered too weak and is less preferred. But these aquas do not require any heating to remove grey or green tones.
But that mine also produces some weak yellow and weak greenish beryls. Occasionally, it will produce a really strong heliodor that looks quite golden but has no greenish undertones.
There is just such a range.
On the other hand, I recently bought some small cut heliodors and cut chrysoberyls on a trip to Teófilo Otoni. One of the chrysoberyls turned out to be a heliodor (based on the RIs, which are quite different).
Note that chrysoberyl actually means "golden" beryl, but it is a different species entirely.
Some chrysoberyls can be greenish and apparently so can heliodors.
But the large crystals of greenish aquamarine are not the same animal. And heat will remove the green, which is not very attractive.
I am only talking about stones from Brazil, of course. _________________ Blog: "Gemstone News and Local Color from Teófilo Otoni" |
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Jason
Joined: 31 Dec 2008
Posts: 254
Location: atlanta
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Posted: Apr 12, 2010 11:21 Post subject: Re: Imperial topaz..whats in a name |
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Hey Luiz..tenney is the one who told me about the shimmer i mentioned and you |
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