DR. HANNEMAN'S MINERAL COLLECTION WILL BE AVAILABLE FOR SALE IN THE NEAR FUTURE
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 Post subject: How about the grandidierite from Madagascar?
PostPosted: Thu Nov 03, 2016 2:06 am 
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I found a special stone in Mada. grandidierite, 0.90 ct, greenish blue, eye clean.

But the price is too high. Something like $4500/pc.

How about the price? is it reasonable?


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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Fri Nov 04, 2016 1:19 pm 
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Hi Madadidierite - nice combination...

Welcome!

You checked this stone - RI and pleochroism?

You want to sell it or buy it?

There is clean Grandidierite - and they are really expensive! The first ones I have seen in St. Marie aux Mines.

I bought two little ones now in Munichshow - one medium to deep greenish blue 0,19ct (SI) and an light to medium greenish blue EY 0,31 ct.

The material is very beautiful - could not resist. We will see in the future whether it
is still extremely rare or not.

They offered a lot of rough translucent to opake material...

http://stonegrouplabs.com/wp/wp-content ... otes-2.pdf

PS: And be careful - a teal tourmaline - namibian for example - is very close in color.

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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Fri Nov 04, 2016 4:27 pm 
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Can anyone tell me what the RI, birefringence and density should be?


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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Fri Nov 04, 2016 4:34 pm 
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http://www.gia.edu/gems-gemology/winter ... madagascar

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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Sun Jan 22, 2017 11:14 pm 
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Looks like my buddy Don Korgen (Thaigem.com and Game of Stones) got his hand on quite a few. He just teamed up with Gem Shopping Network selling Grandidierite in 18k and diamond mountings. One price-2000 bucks for 3-9 carats in mountings. He had about 50 pieces and he sold quite a few. Color was an ok blue green ,mostly on the opaque side. He kept saying it's so rare it's like buying red beryl in large sizes. I don't trust the guy, but he is a good salesmen. I watched the whole show. :D

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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Mon Jan 23, 2017 12:56 am 
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Big opaqueish stones are going for 10-100 dollars on eBay recently from what I've seen.

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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Mon Jan 23, 2017 3:26 am 
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Hi there,
yes there popped up a little bit more the last 1-2 years.
But most of them is opaque material.
I saw 3 different quality levels. The opaque material (where a few dealers got rough at the munich show as well), the transparent stones with many inclusions and the real great stuff with eyeclean clarity from light blue to medium bluegreen.
Last quality is rarely seen and sold online in average around 5000-20000/ct.
Even the second quality is very expensive when you can even get it as 98 % you find is opaque with luck transluzent with strong light.
So interesting to see where it will go and what will come in the future here.
Nik

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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Mon Jan 23, 2017 1:57 pm 
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Nicky Newark wrote:
Looks like my buddy Don Korgen (Thaigem.com and Game of Stones) got his hand on quite a few. He just teamed up with Gem Shopping Network selling Grandidierite in 18k and diamond mountings. One price-2000 bucks for 3-9 carats in mountings. He had about 50 pieces and he sold quite a few. Color was an ok blue green ,mostly on the opaque side. He kept saying it's so rare it's like buying red beryl in large sizes. I don't trust the guy, but he is a good salesmen. I watched the whole show. :D


Hope your "buddy" is not the same "censored" who is telling people incredible nonsense about hunting gems like extremely rare white beryl from Himalaya on TV ( a gem we all want :roll: ...).

The opaque material compared to the clean facetable but small material is like a 10 ct mud ruby without a star from Mysore/India compared to an ultrafine but small 0,40 ct ruby from Mogok.

In my opinion there will come a lot of boring opaque Grandidierite - interesting for healing stone fans or beads.

The clean material is playing in the same league like Benitoite, Vayrynenite or Hauynite - a "must have"!

Just a perfect extremely beautiful collector gem...

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Last edited by Marlow on Mon Jan 23, 2017 2:13 pm, edited 1 time in total.

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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Mon Jan 23, 2017 2:11 pm 
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Stephen Challener wrote:
Big opaqueish stones are going for 10-100 dollars on eBay recently from what I've seen.


If this material is Grandidierite....

We bought some larger and clean stones in Munichshow - nice color and very good clarity around 2-3 ct. Not cheap but a bargain compared to other clean Grandidierite.

Checked my stone at home - RI in the range of Feldspar or Apophyllite.

Calling arglthesheep - same with his stones.

In my opinion it was Apophyllite from India in a bluishgreen color - many specimen around so why not cut some ( I know not easy but if they destroy ten and get one cut)
one. Next day we got the money back. Was a very nice and honourable vendor - there were victims too.

So too large and too clean - red flags like in Moscow 1th of May 1985!

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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Mon Jan 23, 2017 7:55 pm 
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[quote="Marlow"][quote="Nicky Newark"]Looks like my buddy Don Korgen (Thaigem.com and Game of Stones) got his hand on quite a few. He just teamed up with Gem Shopping Network selling Grandidierite in 18k and diamond mountings. One price-2000 bucks for 3-9 carats in mountings. He had about 50 pieces and he sold quite a few. Color was an ok blue green ,mostly on the opaque side. He kept saying it's so rare it's like buying red beryl in large sizes. I don't trust the guy, but he is a good salesmen. I watched the whole show. :D[/quote]

Hope your "buddy" is not the same "censored" who is telling people incredible nonsense about hunting gems like extremely rare white beryl from Himalaya on TV ( a gem we all want :roll: ...).

The opaque material compared to the clean facetable but small material is like a 10 ct mud ruby without a star from Mysore/India compared to an ultrafine but small 0,40 ct ruby from Mogok.

In my opinion there will come a lot of boring opaque Grandidierite - interesting for healing stone fans or beads.

The clean material is playing in the same league like Benitoite, Vayrynenite or Hauynite - a "must have"!

Just a perfect extremely beautiful collector gem...[/quote]
That's the guy. JCK did a good article in 2001 about Thaigem.com's start up (can still be found online ).I got some nice stones but also got burned more than once.l was part of the Brazilian copper bearing that really wasn't ... After testing in the US , these stones were changed to Paraiba -like. On the Gem Shopping show Korgen stated that 20% of the proceeds were going to charity. If I was a gambling man, I would say he 's fibbin :D

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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Wed Jun 07, 2017 7:04 pm 
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Marlow wrote:
Stephen Challener wrote:
Big opaqueish stones are going for 10-100 dollars on eBay recently from what I've seen.


If this material is Grandidierite....

Just a quick update, I bought a few translucent stones and scanned one on my raman spectrometer, and it does indeed test as gradidierite. I suspect there may be some resin filling though--I'll need to get it under the microscope.

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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Sat Jun 10, 2017 9:46 am 
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Please keep us updated.

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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Tue Jun 16, 2020 6:49 pm 
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Love grandidierite, something about it just catches the eye, maybe its the romance of a very unique and rare material playing mind games.

But anyway, reviving this thread to ask if anyone knows the Dispersion value for this mineral? Judging by eye I would say almost as much as a malaya garnet. 0.2
Have not found a reliable source that says the amount of dispersion, only "Strong Dispersion" as a descriptor.

Cheers


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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Thu Jun 18, 2020 12:47 pm 
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Hi TheL
I can't find that specific information either.
It would be possible for you to calculate it yourself:
http://gemologyproject.com/wiki/index.p ... Dispersion


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 Post subject: Re: How about the grandidierite from Madagascar?
PostPosted: Wed Jul 15, 2020 7:44 am 
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Thanks for the info about doing my own calculations, however after reading how to do it i am pretty certain i would fail.
I also did find a webpage describing the Dispersion amount at 0.25 but unfortunately I cannot find the link anymore!!

In any case, the color, fire and knowing it is rare just makes me put these guys at the top of the list for personal favorites at the moment.
If only they didn't cleave so easily, were bigger, cleaner and cheaper ! jaja guess it would end up in par to beryl/aqua at that point...

these are the ones I have cut thus far(0.25 - 0.5ct), gonna keep cutting a few more, the extra effort cutting these pays off when admiring at the end.

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