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 7:32 pm

All times are UTC - 4 hours




Post new topic Reply to topic  [ 6 posts ] 
Author Message
 Post subject: Advice for cutting a tourmaline
PostPosted: Mon Jul 16, 2012 7:30 am 
Offline
Valued Contributor

Joined: Fri Jun 04, 2010 8:21 am
Posts: 421
Location: Australia
I got my hands on some tourmaline pieces a while back. The pieces were heavily included mostly with dirt patches in them. I wanted them fro the interest value as they were mostly bi/multi-coloured. There is one piece that i sawed out of one of the crystals that will facet. The A B axis is a light almost pastel pink with a slight overtone of yellow and presents a quite attractive colour. The C axis is open and is a vivid pink/red.

What would the best way to facet this rough?

_________________
It’s still magic even if you know how it’s done.


Top
 Profile  
Reply with quote  
 Post subject: Re: Advice for cutting a tourmaline
PostPosted: Mon Jul 16, 2012 8:17 am 
Offline
Active Member

Joined: Tue Apr 21, 2009 3:23 am
Posts: 71
Location: Brisbane, Australia
It is very difficult to say for sure without holding the stone in hand, or seeing photographs, but for me it would come down to the shape of the stone.

Decide what shape you would cut on the C, and then decide what shape you would cut on the AB.

Would you prefer a larger pastel stone, or a smaller vivid stone?


Top
 Profile  
Reply with quote  
 Post subject: Re: Advice for cutting a tourmaline
PostPosted: Mon Jul 16, 2012 12:23 pm 
Offline
Valued Contributor
User avatar

Joined: Mon Mar 17, 2008 12:13 pm
Posts: 381
Location: Seattle, WA.
Here's a picture of one cut by L. Bruce Jones. It was yellow on the C axis and more of a gold on the A-B. It was cut on the A-B axis. Notice how the color changes by the quadrant? That's the bleed-in of color from either the C axis or the A-B one. This kind of illustrates that the the color you see in the rough will probably be modified in the finished stone.

Image

:mrgreen: Pete

_________________
Pete (AKA Ruffysdad)
http://www.westerngem.com


Top
 Profile  
Reply with quote  
 Post subject: Re: Advice for cutting a tourmaline
PostPosted: Mon Jul 16, 2012 10:35 pm 
Offline
Gemology Online Veteran

Joined: Thu Jan 03, 2008 3:48 pm
Posts: 707
Location: Vancouver, Canada
Be careful that the c-axis isn't too dark, or you'll end up with a stone that's got fantastic hue but so much saturation it's dead dark.

That happened to me - fantastic rubellite with deep purple-pink on the c-axis that turned into one black stone that only shows the great colour under intense light. *sigh* I should have gone for the a-b axis with it oriented so the c-axis was on the long dimension.

When I get some time I'll snap a pic so you can see what I'm talking about.

-Allan

_________________
Allan Aoyama
http://www.omnifaceter.net <- Omnifaceter is back online!


Top
 Profile  
Reply with quote  
 Post subject: Re: Advice for cutting a tourmaline
PostPosted: Wed Jul 18, 2012 8:15 am 
Offline
Valued Contributor

Joined: Fri Jun 04, 2010 8:21 am
Posts: 421
Location: Australia
Thanks for the replies. After looking at the rough I think i might go with the vivid pink/red c axis. The colour is bright but not saturated. Orienting the rough this way will also give me the greatest return. This is fortunate as the rough is only 1.5 ct to begin with.

_________________
It’s still magic even if you know how it’s done.


Top
 Profile  
Reply with quote  
 Post subject: Re: Advice for cutting a tourmaline
PostPosted: Wed Jul 18, 2012 11:26 pm 
Offline
Moderator
User avatar

Joined: Fri Jun 25, 2010 10:06 pm
Posts: 2267
Location: Chapel Hill, NC / Toronto, ON
If there's one person that knows tourmalines, it's probably Bruce Fry. Take a look at the pictures of his tourmaline collection on the Gemology Project. Maybe send him a PM, and ask if you can send him your rough to see what he thinks?


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 32 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