This medium gray, on blue side, oval was probably heated. It is bright, eye clean and has fine crystal. It weighs 4.29 carats.
I obtained the rough for this medium gray oval from Thailand. It has probably been heated and my principal interest was to see if I could tell the difference between heated and unheated tourmaline. I could not tell there was any difference. The gray is a bluish gray and I have similar that are unheated, in my opinion. I still prefer unheated material, but I am not as concerned about the physical properties of heated material. The gray is eye clean, bright and flashy. It weighs 4.29 carats.
Bruce
About Bruce Fry
I was born in Summit, NJ in 1947 and graduated from Summit High School in 1966. I graduated from the Colorado School of Mines in 1970 and after spending another year in graduate school, I left to see the world of Brazil. After spending some more time discovering myself, I ended up working for the Commonwealth of Pennsylvania for 32 years as an Air Quality Engineer in the Department of Environmental Protection. I retired in 2007 and took up faceting gemstones again after a long hiatus that reached back to my twenties. I had started cutting cabochons when I was 13 and bought my first faceting machine when I was 15, but ran out of money and time until I retired.
My great love in gemology is tourmaline and the collection presented here represents my effort to get as much beauty and variety in the colors of tourmaline as I can. I was particularly lucky in being able to get unheated cuprian tourmaline before copper was discovered in gem grade tourmaline from Mozambique.
This medium gray, on blue side, oval was probably heated. It is bright, eye clean and has fine crystal. It weighs 4.29 carats.
