This is supposed to be green tourmaline. They are 10 to 22 carats. I got my first refractometer today and have been learning to use it. I get 1.54 and then 1.551 with the polarizing filter turned at 90 degrees. On my Presidium thermal tester it gets readings that go from tourmaline to quarts/ Ameth. I get dichroism when viewed through a dichrometer, of green to bluish green. The stones are green when viewed in one axis and blue/green from another.
With a Chelsea filter it is pure green.
Maybe I am just inexperienced with the refractometer. The Presidium readings give me no confidence however.
Quartz? Tourmaline? something else?
![img_342.jpg img_342.jpg](https://www.pricescope.com/community/data/attachments/316/316459-a68e26ee9e5410c404f7270217c40903.jpg)
With a Chelsea filter it is pure green.
Maybe I am just inexperienced with the refractometer. The Presidium readings give me no confidence however.
Quartz? Tourmaline? something else?
![img_341.jpg img_341.jpg](https://www.pricescope.com/community/data/attachments/316/316455-220521743a941548a8f4c37f17ea9810.jpg)
![img_2381.jpg img_2381.jpg](https://www.pricescope.com/community/data/attachments/316/316458-b01dae2dc6b3306a7356bdf11454a867.jpg)
![img_342.jpg img_342.jpg](https://www.pricescope.com/community/data/attachments/316/316459-a68e26ee9e5410c404f7270217c40903.jpg)