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 Post subject: Rare Color Changing Phenomenon
PostPosted: Fri Jul 23, 2021 3:58 pm 
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I’m a gem dealer (not my main profession). I have recently come across one of the rarest gemstones I have ever seen (a unique type of color-changing garnets). They are totally different from other color-changing garnets and they change color by rotating the stone, so there are two colors in the gemstone and depending on the angle you look at the stone you will see a different color. It is the most amazing effect I have ever seen in a gemstone. In natural light, they go from orange to lime green or orange to yellow just by changing their orientation. Interestingly the intensity of daylight can shift their colors a bit too and some of them have the alexandrite effect where the green changes to yellow in incandescent light. As I deal with fine cut gems, I will be cutting some pieces but I feel that they are of great importance to collectors, museums, gemologists, and researchers. As I mainly deal with cut gems, I'm not very familiar with collectors that buy the rough. I wanted advice on where I could find interested collectors, gemologists ... etc. Collectors don't have online profiles so how should I find them?

How do collectors find the pieces they are looking for? Do you have to see the piece, is it word of mouth or through exhibitions, or just online purchases? I would be really thankful to know more about how this industry works.


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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Sun Jul 25, 2021 1:04 am 
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I generally like to see the material before I buy it. Sometimes, if I know a dealer well, I will buy direct from them without seeing it before. The Tucson show is where I spend the most money, generally.


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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Sun Jul 25, 2021 6:08 am 
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How sure are you that these are garnets? Have you shown them to a recognized gemology lab? What test have you run? Can you show us some pictures?


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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Sun Jul 25, 2021 2:50 pm 
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Agree with 1bwanna, what have you done to classify your garnets as a gem like no other color change, color shift garnet? Most if not all true collectors of gemstones are savy and will not bend to sales fluff. They are knowledgeable persons. Tucson is a good place to start, reputation, years in the biz can help. Not to be negative towards your post but a reputable auction house is a great leap to a collectors eye. You will need the former in any case.

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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Sun Jul 25, 2021 5:48 pm 
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What you seem to be describing is pleochroism in a possibly, but unlikely, color changing gem.
Does not sound like garnet to me.
Have you considered submitting a sample to Gem-A or the GIA?
If indeed it is a new, wondrous, collectible material, they will certainly do an article on it for their publications.

That would be the ultimate for you in free publicity and getting the word out.

As I vaguely recall, in the not too distant past, we had another member who was trying to verify the existence of his pleochroic garnet. :smt017 Any one else remember?


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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Sun Jul 25, 2021 6:42 pm 
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There is similar ceramic glass material that is being sold in East Africa as rough color change garnet.

Not saying that is what this is until I see a piece. But it does raise my suspicions. Not sure how any stone in the cubic system exhibits pleochroism.


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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Sun Jul 25, 2021 8:35 pm 
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Thanks everyone for replying. I found the comments & suggestions really helpful so far and am looking forward to hearing more. The reason I say that they are garnets is because of the crystal shape of the gemstones. There are also Tourmaline pieces with same effect which I have a few pieces of too, coming out of the same mines (stones coming directly from the mine). I recently received the pieces and I plan to send them to the lab for verification soon. I have uploaded a video of a piece so people replying to my post can give more detailed replies.

https://youtube.com/shorts/8VvheUdssLM?feature=share


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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Sun Jul 25, 2021 11:15 pm 
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That's not a garnet, luv.
Please send to a reputable lab and get a proper ID.
Good luck.
You may have something else rare and desirable and you don't even know it :wink:


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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Mon Jul 26, 2021 12:47 am 
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Definitely not garnet. Also not glass which is great news. Should be an easy in person.


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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Wed Jul 28, 2021 4:30 am 
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Didn't some Australian tourmalines come in both psuedo-dodecahedral as well as a sort of calcite floater-y shape like the video?
Definitely similar in shape to some garnet crystals

Whatever it is, it's a nice specimen.


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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Wed Jul 28, 2021 3:37 pm 
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@Faodall.... The video link describes that you have several available for sale? what are the details of these pieces? (sizes, weights, etc.)

@Shifter55.... do you know if the term Floater Crystal is just a term to imply or describe a crystal that appears to have no visible point where it was connected to a host? or anybody have any related info to this term? is it a mineral world term?

Is it possible these are Sphene?

Barbra yes I do recall someone claiming their garnets were pleochroic, but do not remember off hand what thread it was.

Thanks

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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Wed Jul 28, 2021 10:09 pm 
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Yeah, a floater is just complete all around.

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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Wed Jul 28, 2021 10:47 pm 
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Stephen Challener wrote:
Yeah, a floater is just complete all around.

Thanks Stephen.
I have been reading a bit about the term floater. Mostly from the mineral world. I like this quote best from the late Rock Currier "Floater is a useful but imprecise term like rare, doubly terminated, Herkimer diamond, cool, bitchen, the bomb, killer or bodacious ta tas that you will have to register with the word police along with its agreed upon definition before we can punish those who use those words incorrectly. However a job with the word police has no salary and we would have to build a lot more prisons to house all the miscreants."
And to all there is no implied criticism from me about how one uses the term.
Quite controversial.

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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Wed Aug 04, 2021 3:41 pm 
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Thanks for suggesting to send the stones to the lab for checking @1bwana1 @glhays @Barbra. I thought the stones are garnets as some had crystal shapes as below:

https://youtu.be/iYO5IjwKHmM


I sent 8 pieces to London for verification and they were all identified as Tourmaline (verbal verification by a gemologist, tested with equipment, refractive index,...) and used a second lab (The Gem & Pearl Laboratory) which is accepted by the industry in the UK to get a certificate and they also confirmed that the piece is Tourmaline (the certificate itself will be ready next week). I'll send a piece to GIA too (it will take 4 weeks as they don't have an office in the UK).
Further, on the discussion, I did research and came accross the Usambara effect and I think it is possible the effect for the color-change. I would like to know your thoughts? I also found an article about it on SSEF (Swiss gem lab), I contacted them and they said it is possible (they haven't seen the stones yet) and said they had only received stones two times before with the effect.
The pieces are in a range of sizes (below ct to +10ct) and shapes and that is why I sent 8 pieces thinking I might have a number of different stones.

@glhays would be happy to talk outside of the platform.


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 Post subject: Re: Rare Color Changing Phenomenon
PostPosted: Wed Aug 04, 2021 4:26 pm 
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I believe you have received positive identification.
Tourmaline makes sense.
The colors you are seeing are the result of dichroism.
This is not a rare color changing phenomenon it is a diagnostic feature of all tourmaline.

Also, this is NOT the Usumbara effect .

It resembles Sunset Tourmaline (Trade name), a variety of dravite from Tanzania.

As Shifter55 pointed out, these pseudo dodecahedral habits are not uncommon in dravite.
Google search
https://www.google.com/search?q=dravite ... 00&bih=609

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@glhays would be happy to talk outside of the platform.

No, sorry, this is not what our platform is for. The use of my bandwidth is intended for informational purposes only. You are welcome to publicly list your prices as a reference guide, but self promotion for private sales is not permitted.


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