CIBJO releases Gemmological Special Report: considers process of separating measurable facts from opinion; See Gemological Articles below.
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Tue Nov 12, 2019 11:09 pm

All times are UTC - 4 hours




Post new topic Reply to topic  [ 3 posts ] 
Author Message
 Post subject: methylene iodide vs water
PostPosted: Wed Feb 27, 2013 10:13 pm 
Offline
Established Member

Joined: Thu Sep 20, 2012 10:45 pm
Posts: 16
Location: Pittsburgh, PA
Specifically looking at the issue of examining a stone for growth lines and color banding, I've heard that using methylene iodide immersion is the way to go. I understand its better than water, but by how much? With stones like corundum and chrysoberyl, is water going to help at all?


Top
 Profile  
Reply with quote  
 Post subject: Re: methylene iodide vs water
PostPosted: Wed Feb 27, 2013 11:54 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19886
Location: San Francisco
The purpose of immersing something in a liquid is to limit reflection and make inclusions and internal characteristics more apparent.
Methylene Iodide is a preferable liquid for corundum and chrysoberyl because its refractive index is very close to those materials. When you submerge these gems in methylene iodide they essentially disappear so that all you see are internal characteristics such as inclusions or growth features.
For emerald, benzyl benzoate is the liquid of choice as its RI is very close to beryl.

I have never used water, but I have used baby oil in a pinch.


Top
 Profile  
Reply with quote  
 Post subject: Re: methylene iodide vs water
PostPosted: Mon Mar 04, 2013 3:43 pm 
Offline
Gold Member

Joined: Sun Jun 28, 2009 9:56 am
Posts: 1224
the idea is to use a liquid which RI is as close as possible to the stone RI range

immersion liquids discussion: http://gemologyonline.com/Forum/phpBB2/ ... =methylene


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 2 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