One of the most brittle tourmalines I have ever cut. emerald cut.

I think that the amount of tourmaline that is available to the custom cutter out of Africa is as bad as it has ever been.  I don’t think that there is much being discovered and the material that is being found is sold to well financed industrial operations in places like China and Germany.  On top of only having a trickle of material, tourmaline rough’s price has gone up very significantly.

In order to keep cutting at least a little bit, I have been picking up some material from sources I have never dealt with before.  And believe me, I do believe in establishing a relationship with my sources of tourmaline rough.  The long thin crystal did not look that promising when I received it.  The a/b axis was rather pale and the axis c was so deep that you couldn’t see more than it was bluish.  I ground a flat for the table and left the whole overly long crystal in one piece.  I kind of anticipated that I would have problems and I did.  As I started to grind down the ends they began to break.   I got one end finished rather quickly, but the other end continued to break until the final distance from the dop was almost the same as the two sides of the nascent emerald cut.  Fortunately I can easily cut an emerald cut that is not centered in either direction with my set up.  Thankfully it did not break as I squared up the sides of the emerald cut because I did not have much width as it stood.  To give you an idea of what I am talking about, the finished gemstone weighs .94 carats and looks to be about 6mm by 4mm.  I roughed out the pavilion with a new 3000 grit standard sintered lap and finished the facets with a well worn 3000 grit lap.  I honestly thought the stone would pop, but it didn’t.  I had to adjust the sides slightly in order to be sure that my corners would be decent and finished the girdle staying away from recutting the ends.  I had had to rework the whole pavilion because the corners on one end had chipped as soon as the stone chattered a little on the new 3000 lap.  A little of the chipping is still there, but I had enough depth to eliminate most of it.

Now a emerald cut that is this small should be easy to polish and the two facets on the keel did not have any problems with chipping when I polished them.  But it seemed like all the other facets either wanted to mark or chip or both.  The small facets on such a small stone move quit quickly on my tin/lead lap, that I keep stationary, with a mixture of chelated alumina and vinegar.  So I spent a lot of time adjusting angles and slightly changing the emerald cuts angles to eliminate the marks without completely loosing my meets.  I saw at least one flaw revealed as I polished, but I also saw that the c axis was a great blue with fine chroma and this little fragile stone had potential.  So I worked on.  By this time the stone and I are in a survival zone, where every decent facet is celebrated.  Finally the pavilion was finished and I could transfer it.  It was so far off center that the receiving dop almost could not accept it.

Now grinding the crown was straight forward and only the polishing of the table usually stands between me and easily finishing the gemstone.  I like to start polishing a table when my quota of patience is full, so on another day we did battle.  As I worked to locate the plane of the table the darling stone let the lap gouge out a couple of good sized canyons.  Now I can polish them out, but I learn a long time ago that it is easier to just recut the table, and so some time was ground away and I started fresh.  This time it got my softest hands and final finished with a flat polish joy.  As soon as I began to polish the step facets around the table, chipping occurred on some facets and others marked.  Now this is the crown and some behavior is not acceptable, but this stone was still in a battle to just survive.  I practically eliminated the vinegar and my pressure became the weight of the faceting hand piece (I have a platform faceter) .  I got quit determined, to the point that I repolished a side facet because it had become too thin while getting out marks on its neighbor.  While adjusting the hand piece and table to repolish and eliminate mark/chips, I kept my fingers crossed because the emerald cut was looking better, color wise, as the polishing progressed.  Finally the last corner facet against the girdle, that had a large grinding scratch, came bright and flat.  It was done, now would I be able to get it off the dop stick.  I start out with wax and transfer to epoxy and boil the epoxy to remove it.  Well the stone came of and nothing chipped!  It is now sitting in my yellowish light and showing me a really, bright, flashy, well saturate blue.  the ends are darker, but still have blue flash and it is a stable blue that is not prone to going green.  It also appears to be eye clean face up.

Now there really isn’t anyway to tell if a tourmaline has been heated to low temperatures to lighten its color, but I think this tourmaline was heated.  But even if it wasn’t, something has made this one of the most fragile tourmalines I have ever worked on.  Its only reasonable future is to sit in the storage box and show off its pretty blue face.  Still I am pleased.

I will post a picture as soon as I can.

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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One Response to One of the most brittle tourmalines I have ever cut. emerald cut.

  1. Pingback: Walking the stone, a rite of passage. A Laurellite moment of a lifetime. | The Bruce Fry Tourmaline Collection

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