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 Post subject: Amethyst from Zambia and Uruguay
PostPosted: Tue Nov 29, 2016 7:47 am 
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Dear friends,
I do know that amethyst is variety of quartz and is quite common. And also quite cheap.
Siberian amethyst, which is almost a "myth" in the gem trade, was another story but is is no more extracted, to my knowledge.
However, it seems that deep and rich bluish purple amethysts from Uruguay and Zambia (siberian-like) are considered really valuable.
I have read that these stones, when are well cut and clean, are sold at 70-100 dollars per carat.
Here an example
http://www.atggems.com/Photos_Quartz.htm
My question is: are Zambian and Uruguayan specimens really rare and more valuable than the other amethysts?
Do they have specific and well acknowledged features?
Thank for your replies! :D


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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Tue Nov 29, 2016 2:57 pm 
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They have nice color, often a biiit overdark but very attractive.I got some soomewhat included rough for 75 cents a gram at Tucson and they cut sme attractive stones. I think the Rwandan stuff is what is hot and new nowadays though--big clean and leans blue.

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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Wed Nov 30, 2016 2:45 am 
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Speaking of Rwandan amethyst, I've been seeing pieces showing up on ebay with good colour tones comparable to the other "Extra" African roughs, with a few having areas similar to lighter rough of the same origin.
From what I can tell the only advantage these pieces have is that they seem to be available in larger sizes without flaws compared to Nigerian and Uruguayan material...
I would say that the narrative of the mine closure is driving prices more than the larger size availability, though the comparison with the pinker South American rough is interesting.


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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Fri Dec 02, 2016 4:24 am 
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......like anything else it all comes down to color, size, availability, etc.

As far as color, in my opinion the Zambian material, with a good blue secondary color is as nice as it gets. I am a fan of the blues though....some folks like the red secondary color, which the original Siberian material supposedly had, but I find the reddish colored ones to =P~ look flat and metallic looking(cough...cough...4 peaks), in my opinion.

I had some fantastic old school Zambian rough, that was picked up in Tucson back in the late 90's or something, that was fantastic.
up to 30cts a piece of clean,cuttable,cobbed pieces of rough with such a strong blue...sold a bunch of it real quick to very happy folks. The Zambian stuff comes from veins that are of a "massive" type, with no, or almost no, fully formed crystals and/or terminations. It's all been cobbed, for the most part. Easy Zambian IDing feature, used to be at least, was the nice rounded cutting pieces that pretty much come pre-formed, if you could call it that. I never saw any Zambian material that had any reddish secondary to it. Always blue secondary, or a flat purple color.

The only Uruguayan material I have handled in a decent amount, was Artigas material. Didn't impress me that much. Good stuff, don't get me wrong, but I liked the Madiera citrine they heat from their ammy's much better than the amethyst. Good clean stuff though.

One of the best pieces of actual rough, of the amethyst variety, that I have seen in person, is that one chunk, which I am sure I have mentioned or posted on here before, from Jackson Crossroads, Georgia. Purple so rich and deep it looked almost black from certain angles...something like 75 grams of purple ice. I will post a pic below

Image

I always find this picture taken by my old friend Michelle Matthews, to really catch the eye. Nice showing of secondary color, or flash, with this Jackson Crossroads specimen.
Attachment:
CrossroadsAMETHYST.jpg
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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Fri Dec 02, 2016 12:54 pm 
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That's interesting.The Zambian stones I picked up were all crystals. Alas, in this day and age I wouldn't trust any fully cobbed quartz rough.

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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Fri Dec 02, 2016 1:51 pm 
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Thank you all, for the kind replies.
I have an oval cut amethyst from Zambia, just 1 ct. It is really deep purple. Nice, but a little too dark, in my opinion.
Never seen Uruguayan material, but it seems to me very nice from the pics I found on the web :D


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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Fri Dec 02, 2016 5:42 pm 
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=P~
Jason Barrett wrote:
......like anything else it all comes down to color, size, availability, etc.

As far as color, in my opinion the Zambian material, with a good blue secondary color is as nice as it gets. I am a fan of the blues though....some folks like the red secondary color, which the original Siberian material supposedly had, but I find the reddish colored ones to =P~ look flat and metallic looking(cough...cough...4 peaks), in my opinion.

I had some fantastic old school Zambian rough, that was picked up in Tucson back in the late 90's or something, that was fantastic.
up to 30cts a piece of clean,cuttable,cobbed pieces of rough with such a strong blue...sold a bunch of it real quick to very happy folks. The Zambian stuff comes from veins that are of a "massive" type, with no, or almost no, fully formed crystals and/or terminations. It's all been cobbed, for the most part. Easy Zambian IDing feature, used to be at least, was the nice rounded cutting pieces that pretty much come pre-formed, if you could call it that. I never saw any Zambian material that had any reddish secondary to it. Always blue secondary, or a flat purple color.

The only Uruguayan material I have handled in a decent amount, was Artigas material. Didn't impress me that much. Good stuff, don't get me wrong, but I liked the Madiera citrine they heat from their ammy's much better than the amethyst. Good clean stuff though.

One of the best pieces of actual rough, of the amethyst variety, that I have seen in person, is that one chunk, which I am sure I have mentioned or posted on here before, from Jackson Crossroads, Georgia. Purple so rich and deep it looked almost black from certain angles...something like 75 grams of purple ice. I will post a pic below

Image

I always find this picture taken by my old friend Michelle Matthews, to really catch the eye. Nice showing of secondary color, or flash, with this Jackson Crossroads specimen.
Attachment:
CrossroadsAMETHYST.jpg


Now that is one nicely coloured crystal! =P~ Makes me want to get back out there right now - but the temperatures are getting rather unpleasant here now :(


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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Sun Dec 04, 2016 8:31 pm 
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I love purple gemstones, which all shift in color depending on the light's color because of the way the eye sees color. But I pretty much gave up on amethyst when I bought (yes I use to buy rough that was not tourmaline) a couple of small pieces for a project. They were from an established dealer who individually displays and sells his stones. When I started preforming the first piece of amethyst, I could clearly see the side of a seed plate. I never bothered even bring it up with him and used it as just another reason for staying in the tourmaline world where bulk diffusion and artificial crystals are unknown outside a laboratory or someone's imagination. Live long and prosper, the few purple cuprian tourmalines left unheated.

Bruce

Nice Georgian purple flasher there.


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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Mon Dec 05, 2016 4:28 pm 
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Benshak Myles recently showed me this parcel of Nigerian amethyst. I had never heard of this material but the quality looks quite high with nice crystal form. So maybe it's something we'll be seeing more of in the future? It looks like it could easily rival Zambian material.
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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Sun Dec 18, 2016 5:09 pm 
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it's amazing...all facet grade amethyst coming from Africa is assumed to be from Zambia. Was surprised when David Challener told me he was unaware of quality Amethyst from Nigeria, am happy though the supply is becoming regular from the mines over here.. Just got his two days ago.


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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Mon Dec 19, 2016 4:29 pm 
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Quote:
it's amazing...all facet grade amethyst coming from Africa is assumed to be from Zambia. Was surprised when David Challener told me he was unaware of quality Amethyst from Nigeria, am happy though the supply is becoming regular from the mines over here.. Just got his two days ago.



This sort of thing appears relatively common imo. Unless you saw something come out of the ground with your own eyes, it's difficult to be 100% certain of actual origin. The stones may have passed through many sets of hands as they travelled the globe and some of them may have their own incentives to re-badge the real origins, not the least of which may be to obtain a higher price. Australia produces a significant portion of the worlds sapphires and it appeared to be standard practice at least at one stage, to re-badge the best ones as being of Thai or Ceylon origin. A poster here recounted a similar experience with a high quality sapphire they knew to have come from Montana being labelled as Ceylon. A similar story - not sure if it has changed - with zircons here. They are produced in significant quantity by the commercial sapphire miners. Yet a jeweller friend told me a few years ago that the supply suddenly dried up. They were definitely still being mined in quantity but appeared to simply vanish into the ether. An acquaintance told me that a commercial miner told him that they are all being exported. What happens to them after that is anyone's guess. I expect some international dealers at some level or levels are simply re-branding them and/or throwing them all in with parcels of stones from other places.

I think it sad but true that place of origin for gemstones traded around the world can be rather slippery, with plenty of motivation and opportunity for deceit.


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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Mon Dec 19, 2016 5:25 pm 
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A bit more that makes me smile,

For quite a while the location of discovery for African paraiba was not public information. Then tourmaline from various other locations in Mozambique began to disappear off the market and reappear in Mavucu. The original location was withheld because the owner does not want to fight "miners" for the good stuff. The"miners" are acturally intermediaries, who try to be the origianal purchasers of the rough at the mines, from the people who acturally do the digging. After marking up the price they would sell to people like my principle dealer. The reason the tourmaline from other locations in Mozambique showed up in Mavucu, is they could get a better price for tourmaline there, at least for a while. It is so bad, knowing the location for tourmaline etc., that my principle dealer no longer claims to know where much of his material comes from,. short of Africa. Finally the legal exports of gems from Mozambique is just a small fraction of what is produced because it is taxed. I have been told that much of it comes out of Tanzania. And the labs really can not help with tourmaline, both because they lack data and distinctive indicators of location for tourmaline.

Bruce


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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Wed Dec 21, 2016 6:35 pm 
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bruce_tourm wrote:
I love purple gemstones, which all shift in color depending on the light's color because of the way the eye sees color. But I pretty much gave up on amethyst when I bought (yes I use to buy rough that was not tourmaline) a couple of small pieces for a project. They were from an established dealer who individually displays and sells his stones. When I started preforming the first piece of amethyst, I could clearly see the side of a seed plate. I never bothered even bring it up with him and used it as just another reason for staying in the tourmaline world where bulk diffusion and artificial crystals are unknown outside a laboratory or someone's imagination. Live long and prosper, the few purple cuprian tourmalines left unheated.

Bruce

Nice Georgian purple flasher there.


Your post about the seed plate made me think of syn. quartz.
I do not trust ametrine when it comes to lab made stones. I did that quick "armchair research", a couple years back, on ametrine and synthetic material being produced in Russia....HA!! Think twice before you buy your next "natural ametrine" from Anahi.
When I buy ametrine rough..well, when i used to buy rough, I always went through . Minerales Metales del Oriente. You couldn't pay me to buy ametrine from any other 'source" LOL

Stephen, most Zambian rough I have had, or seen, maybe had a crystal face or two present, maybe a piece or two had some partial termination, but most seemed to be cobbed/performed to some degree. I checked out some of my old pics of the rough from there, and I had a couple that had partial terminations and crystal faces.
I can't find any reference material in my files, or from online, to reference from, but I am sure I was told that most of the material that made it to market from the ammy belt in Zambia, was pieces, chunks, or cobbed/pre-formed. Don't quote me on that, though..LOL

The amethyst forms in a different type vein system, that does produce euhedral crystals with terminations, like you mentioned, but mostly it's fracture filled veins with amethystine quartz filling the space with not much room for pockets.....generally speaking of course!
I wonder why we never see much Zambian amethyst mineral specimens? I can't recall ever seeing one but I am sure they exist.


We just got to talking about this Rwanda amethyst that is "new" to market(for me at least), and lo & behold, I see Joe H. on facebook with some material from there.

In these pics(from a few weeks ago) he is cuttin' and pre-forming from a big chunk of rough and/or crystal into smaller facet grade pieces
**The blue color in the pics would be out-of-this-world, if it were real, but it has to be under a very cool light or a camera sensor issue, right? :oops:
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Image

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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Mon Dec 26, 2016 7:47 pm 
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found an old picture of two of some nice Zambian facet rough I used to sell...


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 Post subject: Re: Amethyst from Zambia and Uruguay
PostPosted: Mon Dec 26, 2016 8:33 pm 
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Jason Barrett wrote:


We just got to talking about this Rwanda amethyst that is "new" to market(for me at least), and lo & behold, I see Joe H. on facebook with some material from there.

In these pics(from a few weeks ago) he is cuttin' and pre-forming from a big chunk of rough and/or crystal into smaller facet grade pieces
**The blue color in the pics would be out-of-this-world, if it were real, but it has to be under a very cool light or a camera sensor issue, right?


Was in Africa in October and was lucky enough to get some kilos of the Rwanda Amethyst. It is natural material, and the blue color axis is very real, and strong. Strong enough that in some pieces in daylight, blue is the dominant color on an axis. No special light needed. In cut stones, the color change is strong from a very red-purple in indoor light, to a very blue purple in daylight. the material is large, and clean. The blue color is often in zones, and is not in all of the material. If you put it in a polariscope with the nicols uncrossed, on axis is completely blue. Looks a lot like unheated Tanzanite. Lots of red and blue flashes in cut material.


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