This is a beautiful gemstone in a very rare color for tourmaline. Its well saturated lavender color comes from copper and manganese. It is eye clean and has fine crystal. It weighs 6.35 carats.
This round has a horizontally split main pavilion and a deep crown. This helped produce a stronger medium light tone value in the first lavender tourmaline I had ever seen. The stone is eye clean and with fine crystal. This information is pretty standard and does not begin to express my excitement when I received the rough from Africa. It had been a part of a large nodule that was sawed into sections. I am almost positive that it was produced by heating large dark purplish red nodules to partially reduce the Mn+3 to Mn+2, two oxidation states of manganese. This heating effectively reduces and could eliminate, the red component in the gemstone’s final color. Some nodules were completely heated over many hours to produce a very pale blue color or in exceptional cases a fine green. You could not tell before heating the nodule so it was more reasonable to get a lavender, than go all the way and take the risk of getting very little. Now it is obvious that the blue comes from copper, but it was never even mentioned at the time. Even today, some experts will say that a purple color indicates that a cuprian tourmaline gemstone from Mozambique is unheated. This is just not true. Even pictures were posted on the internet, showing the gradual lightning of the dark purplish red material as you extended the heating time. These large, dark purplish nodules were the only truly clean material produced during the early stages of mining in the Mavuco area of Mozambique.
When I finished the gemstone I was so pleased and amazed that I sent it back to the dealer in Africa for him to appreciate. He had never seen a well saturated lavender like it before. After months on his desk it came home with more tourmaline rough that later proved to contain copper elements. Food for posts that have been written and will be written. This historic gemstone weighs 6.35 carats and its cuprian qualities were confirmed with my spectrometer.
Bruce
