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Is this really alexandrite?

Posted by Nick Gilly  
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Nick Gilly June 22, 2018 08:48PM
Seems to be a few chunks of this on eBay from a seller in China calling themselves crystalzhou2015:



He has 3 pieces for sale at present, and this is typical, a fairly large anhedral/massive lump of bluish-green translucent material. It seems odd that there's no demonstration of colour-change that I'd expect if it really was alexandrite. It could just as easily be apatite.

Who knows though, it could be a genuine new find from a deposit in China! Thoughts anyone?
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Owen Lewis June 22, 2018 09:44PM
I wonder if the seller takes the small off-colour patch top-right to be 'alexandrite effect colour change'? I think you are right to be scepticlal, Nick. It will be interesting to see whether/how much for it sells. However, I was unable to find the listing this evening.

I bought my first 'alexandrite in Singapore in 1969 as a present for my mother. I still remember the chinese merchant kindly showing me how to prove it was alexandrite by observing the colour change between illumination with his shop lighting and the sunshine out in the street. What he did not tell me was that it was colour change synthetic corundum (verneuil process). So I didn't get the super bargain that I thought I was getting.
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Nick Gilly June 22, 2018 09:50PM
Hi Owen.

I think the off-colour patch is just a different mineral inclusion, possibly coloured by a bit of iron. Here's the link to the auction:

https://www.ebay.com/itm/Alexandrite-RARE-Natural-Preeminent-Alexandrite-Crystal-Mineral-Specimen/132672025596?hash=item1ee3de73fc:g:UgwAAOSwkIBbK0nj

Also a bit odd that the location is no more specific than 'China'. That doesn't exactly narrow it down!

Edit: the last two sold pieces went for $41 and $36 respectively.



Edited 2 time(s). Last edit at 06/23/2018 07:28AM by Nick Gilly.
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Owen Lewis June 23, 2018 01:12AM
Well, USD 4.00 I'd pay (with free shipping), just for the satisfaction of my curiosity, but I can think of much better uses for USD 40:00.
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Gaye Bishop August 26, 2018 03:30PM
I was interested to note your comments about the Alexandrite. I also purchased some in a cluster stated to be Alexandrite and also some loose pieces from this seller. I was suspect and unable to produce a colour change and took them along to my club. No one has yet been able to work out what it is other than it does not appear to be dyed because of the white/grey Quartz? I polished one of the rough small pieces and it maintained the colour and it is also not granular or like any Apatite that I have. The crystal on the cluster also has included, some Mica formations. I can scratch it with a quartz point. I have included the cluster and the smaller piece I roughly polished to test.

This seller refunded my purchase of another specimen known as Pruskite as I informed him when I found out it was laboratory created and not "accept natural, not perfect" is his motto. However I noticed he is still selling it and not stating it is laboratory created, and strangely a different colour than normal.


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Uwe Kolitsch August 26, 2018 03:49PM
Apatite is a good bet, I'd say.
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Gaye Bishop August 27, 2018 01:46AM
Thanks for your comment. He is selling Apatite too, but the granular variety. I bought that from him as well to compare. I asked him why it was so shiny and he said they coat it with olive oil. I was able to grind the surface and it went back to natural. Is Apatite usually found in clusters like this with Mica and Calcite or Quartz? It is alleged to be found in Madagascar. This seller actually has a supplier so he is on selling as many do, so even the origin could be suspect as well, but so many are coming out of Madagascar to China these days.

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Michael Hatskel August 27, 2018 02:04AM
Gaye,
Try the hardness test: Quartz point shall easily scratch Apatite but not Chrysoberyl (Alexandrite).



Edited 2 time(s). Last edit at 08/27/2018 02:06AM by Michael Hatskel.
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Nick Gilly August 27, 2018 02:04PM
Thanks Gaye. This pretty much confirms my suspicions that he is actually selling chunks of apatite, not alexandrite. A seller to be avoided!



Edited 1 time(s). Last edit at 08/27/2018 03:26PM by Nick Gilly.
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Dmitry Stepanenko February 08, 2019 09:50AM
Hello!

Recently I have got a sample of this chinese material from my friend. Simple gemological tests (hardness, pleochroism, SG and RI) show that in fact this is grandidierite. As Gaye supposed, this material comes from Madagascar.

Best regards,
Dmitry.



Edited 1 time(s). Last edit at 02/08/2019 09:56AM by Dmitry Stepanenko.
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Nick Gilly February 08, 2019 05:50PM
Thanks Dmitry. I assumed it was apatite based on Gaye Bishop's post mentioning that a quartz point could scratch it. Grandidierite is a lot more interesting than apatite ;-) Maybe I should try my luck with one...
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Dmitry Stepanenko February 09, 2019 04:56PM
Hello, Gaye!

As I see, there are dendrites of black material (probably manganese oxide) in white host rock?
As I already wrote, your stones are grandidierites. These dendrites seem to be typical for Madagascar grandidierites: I see them in my sample too.

Best regards,
Dmitry.
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Alix Julien February 10, 2019 08:45AM
Hello everyone.

I have already bought from this seller and I watch a few articles of time and it is true that there are from time to time identification mistakes:
Cuprite var. Chalcotrichite called just Cuprite or Arsenopyrite called just Pyrite for example ...
it gave me the opportunity to buy that (under the name pyrite and associate) and not expensive:
- Muscovite on Ferberite & Arsenopyrite - Yaogangxian Mine, Yaogangxian W-Sn ore field, Yizhang Co., Chenzhou pref., Hunan prov., China





Sometimes it is the seller that shoots itself in the foot :)
There are occasionally problems of identification on Ebay so always pay attention.

See you soon

Alix JULIEN



Edited 1 time(s). Last edit at 02/10/2019 08:47AM by Alix Julien.
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Nick Gilly February 10, 2019 11:22AM
Hello Alix.

I know exactly what you mean. I bought several nice specimens cheap on eBay last year because they were misidentified, e.g. ruby sold as spinel, spinel sold as zircon, phenakite sold as topaz, and Russian alexandrite sold as epidote! A couple of these were from mineral dealers too, which is all the more surprising.

Ruby is a good one because it sometimes forms pseudo-octahedral crystals which cause some sellers to assume it is the less valuable spinel.



Edited 1 time(s). Last edit at 02/10/2019 11:23AM by Nick Gilly.
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