Fried Tourmaline and the Quest for Purplish Blue Color.

The roots of my quest for purplish blue tourmaline, goes all the way back to my renewed determination to cut and collect tourmaline over 10 years ago.  I wanted all the colors in the rainbow and more, which leaves tourmaline as the only practical gemstone with the capacity to please me.  I could have cut all sorts of different gemstone, but after spending a great deal of time and effort perfecting my procedures to produce a superior finish on tourmaline, I decided to specialize in it.  I had also fallen in love with the gemstone many years before, but family and work had taken presidency of my passion for many years.

I have run into and purchased “fried” tourmaline a significant number of times while searching for purplish blue color.  Most of the time the “fried” skin of the crystal has to be removed in the cutting.  This is because the skin is usually thin.  The thin pinkish skin is caused by natural radiation oxidizing trace amounts of manganese in the bluish gray body of the tourmaline.

Now you would think that I would have learned not to get crystals that I have not even completely cut, a couple of time before, because of flaws, size and a very pale color.   But I have had successes with similar material, such as the first Laurellite (cuprian reverse Alexandrite color changer) and a beautiful set of gray gems, which keeps me seeking more.  The subject of this post is to the describe/announce the final completion of one of these “fried” tourmaline crystals.

The crystals are usually not very thick and have significant striations.  Their c axis is open and shows the best color which can appear to be a mixture of the blue gray center and the pink skin.  This is basically a deceiving feature of the crystal and the only pink color that can be retained in a practical gemstone is in the edges of the crystal, which must be placed on the keel.  I guess you could try and cut something besides an emerald cut, but that is the only pattern I have tried.

The gemstone I just finished is about a carat in weight and has the first set of steep ends on an emerald cut, that I have ever cut in a tourmaline with a very transparent c axis.  I hoped by cutting the ends steeply that I would retain as much pink as I could.  That is because the pink, in the keel, is really the only color that has a decent tone value.  The grayish blue is both neutral and pale to the point of being completely forgettable.

So what do I see in its color on the third try and counting, of getting a purplish blue gemstone stone out of “fried” tourmaline.  I see a very bright emerald cut that is included.  The main body of the gemstone is very pale and displays a hint of pink face up.  When I tilt the gemstone I see a bit of mixing that produces a violet overtone on the pink,  while the ends flash the stronger c axis pink color.  It is different, but I am disappointed that the grayish blue is so pale that it has very little impact on the stronger pink color, even though it is in more of the crystal.

I am pleased in my effort with this piece of tourmaline.  It took a significant amount of effort to minimize significant flaws and retain some pink in the keel.  I am ready to go on with more expensive rough in the new lot from Africa.  More stories to tell.

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.

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