This colorless oval could have possibly been heat treated since it went threw Thailand from where ever it was mined. The principle reason I purchased the rough was to see if heating effect it, in a way that I could tell. I wasn’t able to see any difference in the four pieces I bought, from run of the mill unheated tourmaline.
This oval is eye clean and completely colorless. It weighs 3.16 carats. I have some identically colorless tourmaline that I feel sure was not heated. The inability to determine heating or not, makes the heating question of little consequence.
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.
