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 Post subject: How to diffrentiate between Chrome tourmaline and Tsavorite
PostPosted: Sun Aug 24, 2014 9:28 am 
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Dear sir,

I had a parcel of chrome tourmaline and tsavorite got mixed in(by the guy i was showing the parcel to). Its quite a big parcel and sizes are mostly small. I dont think i can get each stone checked with a gemmological lab. Is there any easy way to differentiate between chrome tourmaline and tsavorite rough?

Any help will be greatly appreciated as i am trying to find a way to separate them for last 3-4 month but I didnt find any definitive method yet.

Please help. thanks


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Sun Aug 24, 2014 3:00 pm 
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The two minerals have differing densities. Get a small amount of the correct density liquid and place the mixed crystals in the liquid. The tsavorite will sink and the tourmaline will float. Check out these guys for heavy liquids: http://www.cargille.com/heavyliq.shtml

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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Sun Aug 24, 2014 3:23 pm 
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OK, here's what you do. Tsavorite is a garnet, so it's isometric/singly refractive, while tourmaline is doubly refractive. Get a cheap LCD monitor at a garage sale or something, have it show a white screen, set it sideways on a table. Put the parcel of rough on it and wear polarized sunglasses. The LCD puts off polarized light, which the sunglasses will filter out entirely (as long as the monitor and sunglasses aren't aligned, but then you'd just need to go to the other side of the table). The garnets will not change that polarization, so they'll be black. The tourmaline, however, will split and repolarize the light that enters it and thus will not turn black (unless it's closed C-Axis, in which case it can be black at one orientation, but this doesn't look like it). Regardless, that might be a quick way to sort them out.

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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Mon Aug 25, 2014 9:10 am 
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Wow thanks for the very fast response my question : michael_e and Scarodactyl.

Dear michael_e
i followed the link you gave, its very helpful. it got me thinking if i can use Diiodomethane or Indiumiodide for this. Actually it will be costly for me to get 400cc liquid shipped to here in thailand from usa. not to mention i dont know if i can import or customs will seize it. hence i will be looking for local suppliers if can be found or wait till i come to next Tucson show, maybe i can get it from Tucson electric park show.

Dear Scarodactyl
I will try your method first as its cheap, i can get components from market and no dabbling with heavy liquids.

Thanks both for the replies. i will post my results by next week!!


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Mon Aug 25, 2014 1:13 pm 
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Or, just use your polarized glasses. You should be able to easily tell them apart.

:lol: For all you people who wouldn't want to be caught dead using a filter, don't try this. A polaricope IS a FILTER. :lol:


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Mon Aug 25, 2014 1:19 pm 
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LOL, touché, Dr. Hanneman! =D>


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Tue Aug 26, 2014 3:44 pm 
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A little late to the party, but...

Another tool you could use to separate the tourmaline from the garnet is a 405 nm (violet) laser pointer. Illuminating a chrome tourmaline with this laser light will cause it to glow deep red. Whereas all the saturated color tsavorites I've illuminated show no reaction at all.

I have seen some pale merelani mints glow, when illuminated with violet laser light, but even then their glow was orange-yellow... distinctly different from the red glow of chrome tourmaline.


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Tue Aug 26, 2014 10:56 pm 
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Brian wrote:
A little late to the party, but...

Another tool you could use to separate the tourmaline from the garnet is a 405 nm (violet) laser pointer. Illuminating a chrome tourmaline with this laser light will cause it to glow deep red. Whereas all the saturated color tsavorites I've illuminated show no reaction at all.

I have seen some pale merelani mints glow, when illuminated with violet laser light, but even then their glow was orange-yellow... distinctly different from the red glow of chrome tourmaline.


Dear Brian
can you check these 2 links from ebay? one is 5mWatts other is 1 mWatts. which one is better suited for my work?

http://www.ebay.com/itm/Powerful-Blue-V ... 27e9a86652

http://www.ebay.com/itm/Purple-Blue-Las ... 233b1ae7a0

And thanks for the idea!!


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Wed Aug 27, 2014 9:18 am 
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Either will do.

Let us know how it goes. :)


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Wed Aug 27, 2014 9:36 am 
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Brian, will that work on other stones the same way exposing them to lw/sw uv light will? That would certainly be a lot more convenient than a big bulky uv source.


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Wed Aug 27, 2014 2:45 pm 
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Most anything that fluoresces under LWUV will have a stronger reaction to the laser light. But then the laser light will also cause materials to fluoresce that don't normally show a reaction under LWUV. Many, many materials. So it isn't really a replacement for LWUV.

A better alternative would be a "UV LED flashlight". You can just type the name written in quotes into google or ebay to find as many as you please. The LEDs in this little flashlight emit light at wavelengths around 400 nm, so they aren't really UV and they aren't a perfect replacement for LW-UV. Bear Williams wrote an interesting article about these LEDs.

And as of now, there isn't any inexpensive way to replace SWUV lamps.

Finally, it is really weird seeing 405 nm laser pointers costing less than 400 nm LED flashlights. At least a hundred times the ouput for half the price!


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Wed Aug 27, 2014 3:09 pm 
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I really like mine, but I'm always scared I'm going to blind myself with it. Seeing it make minerals that would normally only fluoresce phosphoresce is pretty awesome, though!

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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Wed Aug 27, 2014 8:33 pm 
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Scarodactyl wrote:
but I'm always scared I'm going to blind myself with it.

If you get a Kodak Wrattan #4 filter, it will block the laser light while letting the fluorescence shine through.

And KaptanRough, one last point while I'm thinking about it. You may find that nothing fluoresces if it is spread out on white paper or white cotton. I don't know why, but those material can kill a gem's reaction.


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Thu Aug 28, 2014 2:11 am 
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Hi Brian, now I'm all exited about using this tool to go night-time searching for zircon and sapphires.
Have you shone it on said stones?
And diamonds?, as we also have diamond occurence in our area.
Barry.


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 Post subject: Re: How to diffrentiate between Chrome tourmaline and Tsavor
PostPosted: Thu Aug 28, 2014 9:42 am 
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hi Barry

Beyond chrome tourmaline and tsavorite/merelani mint, I haven't really explored much. :oops: It was just fortunate that the poster's request happened to match my experience.

A while ago, Barbra put up a table of her observations of gemstone reactions to 405 nm laser pointer. I suppose no one has tried zircon.

At the price point of these lasers listed on ebay ($3!!), probably worth the gamble.


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