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Rare Alkali rich blue beryl called Vorobyevite. Huh?
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Author:  Jason Barrett [ Sun Jan 27, 2019 10:31 pm ]
Post subject:  Rare Alkali rich blue beryl called Vorobyevite. Huh?

I must've missed class that week, because I don't recall reading or hearing about "V
I was cruising around on Ebay, when I came across this ad and crystal. I couldn't remember ever hearing that name used before, outside of its normal mineralogical.context.
I had to look and see what was up with these stones....
I guess its unique enough to be of note,....
but not enough to be a different species altogether.
EBay ad where I saw the name "Vorobyeite beryl" for the first time, just now.
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I've just read a few paragraphs here and there, while online earlier. I found Lavinskys page to be pretty good in terms of pictures and variety.
This is info from Rob's Arkenstone website, over on Irocks.com.

Vorobyevite (Rosterite) - Unusual Beryls

July 13, 2014 - Vorobyevite (sometimes called Rosterite) is a rare variety of Beryl that does not qualify as its own species. The name was applied to both colourless cesium-bearing beryls from the Urals and rose-coloured and colourless alkali-rich beryls from Madagascar, all of which showed sharp hexagonal crystals which are shortened on the c-axis. This new find had a similar morphology, which led to puzzlement over what it was. Although the morphology of these crystals is clearly unusual (see photos), and although the crystal habit of these strange beryls is similar to Pezzotaite (which is a valid species of beryl), these do not contain enough cesium OR OTHER ALKALI to be classified a new species under current mineralogical rules. To be sure of the classification of this unusual material, when the pocket was found, we sent the whole lot to the lab of Dr. Federico Pezzotta in Milan. He performed analyses on multiple specimens to show that one can consider these to be ALKALI-rich, EVEN IF NOT PARTICULARLY CESIUM RICH COMPARED TO OTHER EXAMPLES, and he believes this is the reason for the crystal habit we see here (bowed-in centers; sandwich-like look on the edge faces with color zoning; and unusual sharply tabular morphology). I was able to buy nearly the entire pocket of this material, which I was told was mined in mid-2012 in the summer season. The altitude is a problem - it is difficult to access and the mining season here is only 3 months. No more were found in 2014 to date, despite an attempt. While we were initially told the specimens were from Gilgit, we now have better confirmation that the locality is Deo Darrah, Khash & Kuran Wa Munjan District, Badakhshan Prov., Afghanistan.



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https://www.irocks.com/galleries/arkens ... t-pakistan

Author:  Stephen Challener [ Mon Jan 28, 2019 12:43 am ]
Post subject:  Re: Rare Alkali rich blue beryl called Vorobyevite. Huh?

Yeah, it's kind of an obscure term outside of the particular samples mentioned in the iRocks article. The flattened roselike crystals also tend to have a strong blue color, and are widely available. Maybe because of the similar color the term sometimes gets applied to these other, more normally shaped beryls with unusual rich blue zones (which are a bit odd in and of themselves, with elongated columnar zones of rich blue often forming a rind towards the outside of the stone. I thought they must be tourmaline inclusions or something when I first saw them, but under the scope they appear to just be colored zones.)

Author:  arglthesheep [ Mon Jan 28, 2019 2:39 am ]
Post subject:  Re: Rare Alkali rich blue beryl called Vorobyevite. Huh?

Hi Jason,
yes around 5-6 years ago they where hyped as Vorobyevite specimen from Irocks and on some bigger fairs.
As you wrote they were checked and are not caesium rich. So they are beryl in some weird growing situations. We have also a rose and some other interesting specimen from them. But the hype is gone, as they are not that what they meant to be.
They are nice and interesting but seem to be nothing special.
They were hard to get in the beginning, but now you can find them easier and far cheaper.

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