Totally inappropriate behavour with a strange twist, green emerald cut.

This post is on a personal trip down a path that I have just begun to travel with determination.

The market in tourmaline is so bad for a custom cutter/me that I have decided to actively pursue getting only rough that can not be “cleaned” up by any reasonable effort.  I still want vivid colors and good crystal between the “naturals”, but inclusions will be present and not just as an unfortunate guest.  The following post is about one piece of rough I recently got from Africa that came in my first lot of only significantly included rough.

I had seen her sisters before and she fit right in.   A water worn natural cross section of a medium sized crystal that had a green c axis that became too dense in natural light and an outstanding blue/green axis that shown beautifully in all lights.   She was also significantly included and at first glance, it appeared to be standard round brilliant material with the c axis perpendicular to the table.  Still both of her sisters had frustrated me.  They promised more than they had delivered  and the denser c axis in natural light was both quite unusual and made them only really shine in incandescent/yellow light.  Did I really want to cut another piece of rough “normally”, that really had great potential, but was severely limited by its shape?  No!

The moment came quickly and my emotions flared.  I would make her shape conform to the color needs of the finish gemstone rather than yeild to my quest for size.  I quickly got out my diamond saw and slit her down the middle into four more or less equal pieces.  Gone was the day of having a nice size ring stone and in its stead, I had four,still included remnants, that would produce at most a carat stone each.

What had I gained by this obscene act?  I could isolate the denser green axis in the ends of small emerald cuts and finally see the pure beautiful a/b blue green as I really wanted to.  At least this was the plan and I am in the middle of cutting the first piece.  I will finish this post when I finish the less than half carat emerald cut.    You will find a couple of surprises in the end I am sure.

Morning has broken and the 1/3 of a carat, 5mm by 3.4mm emerald cut is finished.  The low yield from approximately a 1 gram quarter of the original piece of rough was caused by fighting a battle to eliminate a life threatening flaw.  Now I preached that I was accepting of the flawed ways of tourmaline in my present quest, but some flaws, particularly one that are perpendicular to the c axis (radial flaws) make the finished gemstone prone to break.

The first step in eliminating the radial flaw, that was quite distinct, outside of cutting the original rough, was making a crude rectangular solid.  Then I had to grind one of the long edges to make the nascent table.  This proved so difficult to do with this small piece that I had to dop the semi-preformed rough. While I had the rough dopped, I also squared up the sides of the preform. This is very unusual for me, but I was determined to do the best I could for this piece of rough.   After transferring the stone to another dop stick I had to grind the final girdle facets to both eliminate the radial flaw that was now on the side of the nascent emerald cut and establish a girdle.  This whole effort was made more difficult and problematical by needing to move the rough closer to the center of the dop stick.  A miscue in this move would make a ample amount of effort to get anything from the rough.  The rough did rotate some and I had to grind my dop stick a significant amount to get the shape of the girdle without the flaw, but the effort did work. (The emerald cut does not have to be perfectly centered for me to efficiently finish the stone.) With the radial flaw finally gone the finishing of the small emerald cut was trivial.

I did notice the following things about the evolving stone as it was quickly finished.

1, The smaller emerald cut’s tone value was only moderate now and the density of the c axis color was not going to be a problem.  I therefor cut an emerald cut with normal angles on the end.

2,  The stone was going to be not only eye clean, but lop clean when finished.  A feat that I had not set out to do and felt from the beginning, could not be done.  I was chagrined to say the least, but the old flawless ways die hard I guess.

3,  Just before finishing the crown, I realized that a tiny bit of an old girdle facet was still there on the end of the emerald cut.  It really makes no difference in the gemstone and could not reasonably be eliminated.  Still it showed to me how intense the effort had been to just get a 1/3 carat gemstone out of the piece of rough.

So I have seen the gem in incandescent and morning light.  It likes the yellowish light, like many green and blue tourmalines, but it does not darken with the dawn.  I really reminds me of a small piece of “sea foam” tourmaline that generally comes from Afghanistan.  Because the rough had been water worn, it probably came from Africa because Afghanistan does not produce water worn material.

I think the other four 1 gram pieces will probably produce a bit bigger gemstone, because, while being flawed they do not have life threatening flaws.  Perhaps with a larger size, they will look a little more like the rough, because I would have never guessed that this small emerald cut came from the rough I sliced so maliciously in an act of totally inappropriate behavior.

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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