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 Post subject: ebay fraud the other way around, a little story
PostPosted: Thu Nov 11, 2021 4:42 pm 
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My principle when shopping for gemstones is that what is too good to be true is never true. So I make fun of it every now and then and look for appropriate offers. I found it on eBay (where else). 4.6 ct reddish orange not heated copper tourmaline from Mozambique, minimal inclusions, really nice color on the photos and a usable cut. No limit and starting bid at $ 1. Surcharge for $ 78, in words seventy-eight!! What a bargain.

After 14 days unpacked an checked.
4.6 ct.,
nearly eyeclean,
RI> 1.79,
no birefringence,
SG 4.17,
magnetic

I was slightly pleasantly surprised now. I had expected a total failure.

Nonetheless, such sellers have to be patted hard on the fingers. The best way to do that is through reputation and money. So I wrote to the seller that the tourmaline advertised is a garnet and I expect him to sort it out. As expected, no answer. So I told him I was going to give him the worst rating he'd ever gotten. I would also contact ebay directly about fraud. But I would be interested in an amicable settlement.What can I say? Money back and keep the stone.
Now it was a real bargain.

It was fun for me. And because it was so good, I bought 4 pink-red-orange copper bearing tourmalines from the same seller. I'm really looking forward to unpacking. Sequel follows.


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 Post subject: Re: ebay fraud the other way around, a little story
PostPosted: Thu Nov 11, 2021 5:06 pm 
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8) Looking forward to the sequel.
"The BargainHunter II"

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 Post subject: Re: ebay fraud the other way around, a little story
PostPosted: Mon Dec 06, 2021 8:41 am 
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2nd sequel

Stones arrived.
SG between 3.09 and 3.15
RI 1.631 - 1.64
Birefringence 0.018-0.023
strong pleochroism

So it is 4x tourmaline. But copper tourmaline?

A few months ago I bought a small gemlab spectrometer. Since I don't have a reference for pink-red tourmalines, I'm now a little skidded. #-o ](*,) :-k
Maybe one of you has an idea?


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 Post subject: Re: ebay fraud the other way around, a little story
PostPosted: Mon Dec 06, 2021 11:00 am 
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Most of the inexpensive spectroscopes do not go high enough to properly test for cuprian Tourmaline. I don't know about the one you have. Look in your manual to see.

It must be capable of accurate readings in the 900+ nm area. There should be a large peak in that area if the stone has copper.

The the second graph below is one I took. The red line is my reference stone, the black line is the subject stone, which the graph verified that it has copper. This was done on a piece of rough from Mozambique.

The first graph is for another piece of rough from the same parcel that looked identical. As you can see, no copper. It is flat in the 900nm band area.

Your stones also look flat in that area, but it may be because of the limits of the scope, not the stone.


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 Post subject: Re: ebay fraud the other way around, a little story
PostPosted: Mon Dec 06, 2021 2:36 pm 
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Steve trying to understand your graphs. The first image.
The red line is a reference right, and the black is the stone in the test? If so where in the line @900 on black line should I see what is needed for it to have copper. I have no experience reading these.

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 Post subject: Re: ebay fraud the other way around, a little story
PostPosted: Mon Dec 06, 2021 3:20 pm 
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Greg,
You can see in both graphs that I have drawn a reference line at around 917nm. That is the reference line for copper in a UV-VIS-NIR spectrometer like I have. It is accurate in the 300-1,000nm range. Most less expensive ones don't go that high. The red line shows a big hump in that area for the reference curpian tourmaline.

In the first graph you can see that there is no matching hump in that area for the black line which is the sample being tested. This lack of peak in that are indicates no presence of copper.

In the second graph you can see that there is a nice peak in the black line in that area indicating the presence of copper in that stone. It is cuprian tourmaline.

I hope that was a clear enough explanation.


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 Post subject: Re: ebay fraud the other way around, a little story
PostPosted: Mon Dec 06, 2021 3:29 pm 
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I did note a lack of humps around 900 on the ebay stones' spectra. On the other hand perhaps they do contain copper that just isn't affecting the color. Certainly to the eye manganese is the only active ingredient given the lack of a blue component to the color, regardless of potentially homeopathic levels of copper.

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 Post subject: Re: ebay fraud the other way around, a little story
PostPosted: Mon Dec 06, 2021 4:19 pm 
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1bwana1 wrote:
Greg,
You can see in both graphs that I have drawn a reference line at around 917nm. That is the reference line for copper in a UV-VIS-NIR spectrometer like I have. It is accurate in the 300-1,000nm range. Most less expensive ones don't go that high. The red line shows a big hump in that area for the reference curpian tourmaline.

In the first graph you can see that there is no matching hump in that area for the black line which is the sample being tested. This lack of peak in that are indicates no presence of copper.

In the second graph you can see that there is a nice peak in the black line in that area indicating the presence of copper in that stone. It is cuprian tourmaline.

I hope that was a clear enough explanation.

Yes it did, Thanks!
Also helped looking at it on a monitor verse a phone after I read this.

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 Post subject: Re: ebay fraud the other way around, a little story
PostPosted: Tue Dec 07, 2021 5:36 pm 
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As Stephen pointed out, ""copper schmopper."

The presence or absense of copper in no way effects the color or value of these tourmalines.

A meaningless buzz word used to infer added value.


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 Post subject: Re: ebay fraud the other way around, a little story
PostPosted: Tue Dec 07, 2021 5:56 pm 
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Thank you for your explanations.

@Steve
When I look at your pictures I think we used the same hardware (GL Gem Spectrometer). I just used other software to show the results of the measurement.

@Stephen
Now I don't have to return my spectrometer after all. I have a green tourmaline there. The gemological report states that the stone contains traces of copper. But the result looks > 800nm exactly like the pink-red stones. I have two certified Paraiba tourmalines that show exactly this peak at 917nm that Steve showed and described. I was pretty confused.

@Barbra
Now I am a little concerned about the reliability of the gemological report. I don't expect anything else from a "convicted" eBay seller. But a gemological report should be honest, not misleading and, in particular, should be understandable for laypeople who (must) rely on it.

To try out and "play":
The program is much more comfortable in its functionality than the software supplied with the GL Gem Spectrometer. Among other things, 77 data formats are recognized and the program can be used for all common spectroscopy methods. Free for private use. If you are interested: https://www.effemm2.de/index.html


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 Post subject: Re: ebay fraud the other way around, a little story
PostPosted: Tue Dec 07, 2021 6:33 pm 
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Tourmaline can be an elemental garbage can.
I wouldn't be surprised if many untested tourmaline specimens contain copper and a litany of other undisclosed elements.

When should the presence of copper impact the value of tourmaline? When an astounding, rare, vibrant neon color is the result of the presence of copper, regardless of origin.

And when one is trying to seperate it from some of the pale blue Afghani samples which don't contain it. They are colored predominately by iron.
Another illustration of 1Bwana1's point
GemstoneMagnetism.com wrote:
Image


I have posted some examples in the past of bug juice colored tourmaline with the presence of copper detected in it's spectrum. I have also seen the owner of these stones attempt selling it at a premium because of copper content.


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