January 24 Through February 4—TUCSON, ARIZONA: Annual show
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Thu Mar 28, 2024 4:12 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 1 post ] 
Author Message
 Post subject: A bright flashy 5mm round tourmaline of note.
PostPosted: Fri Apr 01, 2016 10:56 am 
Offline
Gemology Online Veteran

Joined: Thu Sep 25, 2008 10:33 am
Posts: 840
Location: Mars PA
I have posted how dry the well of tourmaline rough has been and that I was cutting rough I would not have spent time on in the recent past. Well I received a care package from Africa and while I greatly appreciate the ability to work again, the rough is more challenging than usual. But a beggar can not be choosy.

I just finished a very nice vivid green round with a bluish blush from the rough I just received. It is exceptional for several reasons. One, I normally don't buy rough like this piece was cut from. The mostly green tourmaline was strongly dichroic and the rough was a short stubby crystal with the sides perpendicular to the semi closed c axis ends much larger than the length down the crystal. And on top of that, there were residual radial flaws that had not been completely removed from the rough. Still the piece was big enough to slice with my saw and get a decent gemstone or two out of it. A single round with the semi closed c axis perpendicular to the table would be dead and any emerald cut with the long dimension perpendicular to the c axis would be mostly lifeless. So what to do?

I have had some success cutting rounds from dichroic tourmaline recently so that is the path I took. By slicing the triangular rough twice, with a significant loss in weight, I had three pieces, one of which was badly flawed and two clean semi preforms ready to cut, about 5mm, rounds. The nascent tables are parallel to the c axis and quite open, but the key is how open and colorful the side of the round perpendicular to the c axis will be. The cutting and polishing went easily and I could feel the glow of excitement flowing from the stone as I saw its color and transparency, under my incandescent work lights, revealed.

I am amazed, but under my incandescent lights, the bright vivid color of the round, cut with the table parallel to the c axis, is completely without indications that the stone is dichroic. (Of course this is without magnification or more than a casual look.) The point to be made is not that this stone is perfect, but that it is a really nice piece from an impossible piece of rough. But then I tried to temper my enthusiasm and wait for the light of a new dawn, because maybe the dark sides would darken too much in daylight. Well the sun is out after a gray beginning and the pretty 5mm round's color has shifted to the bluer and less vivid end of the spectrum, but it is still open and flashing hello. The two sides of the round that are effected by the c axis are darker and with a more noticeable color difference, but that has only a minor impact on the round. (I am smiling.)

I call rounds like this 5mm beauty, droplets of color on my website brucefrytourmaline.com and if you visit you will be able to see many more of them. A full tray can even satisfy my craving for color in tourmaline for a brief time. And with this modest format, color barriers can be broken and more beauty reveal in the complex and wonderful world of color in tourmaline.

Bruce


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: Google [Bot] and 23 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Gemology Style ported to phpBB3 by Christian Bullock