Historic lavender deeply cut round, Mozambique, cuprian#31

Eye clean, deep pavilion, lavender round.  #31 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

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 entry was posted in Cuprian Tourmaline, Etc., Personal Stories and tagged , , , , . Bookmark the permalink.

Leave a Reply