OK, this is hardly a "timely" update, but here it is. Last year, for Mother's Day, my daughter came from California for a visit (I moved back to the U.S. a few years ago), and we decided to go to Tyler, Texas, and stay at a B&B so I could take some of my stones to Richard Armstrong, RG, GG, GP (www.armstronggemology.com) so he could test them with his spectrometer from the Canadian Institute of Gemmology:
https://www.cigem.ca/research-technology/gl-gem-spectrometer
And what do you know! It turns out that the blue portion of the tourmaline is copper-bearing and the pink portion is not!
Note that the colors in the photo in the original post are not correct. I don't own a professional DSLR camera, and I don't know how to correct the colors in the images I get from my little P&S. That is to say, the dingy brown should be gone from the photo below. The pink and blue are bright and lovely.
So, what I am going to do next is send the stone for origin testing by the GIA.
https://www.gia.edu/gem-lab-service/colored-stone
Iridescent tourmalines are so pretty, aren't they? I still haven't managed to get a nice one for myself, though.
Yes, I once had very good stones there for very good prices; however, the consumers here were not able to recognize this, and sales became difficult when so many competitors selling worthless stones came on to the scene.
I still have some of that druzy if you are interested. It is such an incredible natural color. I was worried that it was a dyed color, so I left those stones outside on a windowsill in the hot sun for 6 months -- no color fading at all!
Oops! I think all of that druzy is now in Illinois. I visited my daughter in August and left most of my good stones there.
I will be putting up some Mali grossular garnets on the Search 4 Gems site, as soon as my daughter can get them back to the U.S. in mid January.
If you are in Brazil, perhaps I can put some stones on a flickr or picasa album for interested buyers here.
Best regards,
Tenney
I am probably not going to sell the stone just now.
This is due to the fact that it is strongly resembles the colors of Paraiba tourmalines -- that is, if you are familiar with a lot of the colors that show up in the matrix -- pink and blue. I am not talking about the good quality crystals that are cut and heated.
When I saw these bicolored stones in Teofilo Otoni, it hit me right away that they could be from Paraiba. So, I got the biggest one -- it was not expensive, but of course we are talking about the price in Teofilo Otoni.
I will probably send it to a friend who has a spectrometer to see what he can see.
But thank you for your interest! I am having to set aside my gem studies for the moment due to taking a huge load of classes at university, but I will be free this summer to pursue gem interests, and I am very glad you reminded me about this tourmaline. I will try to have it analyzed. This should be interesting!
Best regards,
Tenney