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 7:48 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 5 posts ] 
Author Message
 Post subject: how to separate heated and unheated blue sapphire ??
PostPosted: Thu Jul 29, 2010 11:24 am 
Offline
New to the Forum or The Quiet Type

Joined: Thu Jul 29, 2010 10:51 am
Posts: 3
How to separated natural heated & unheated blue sapphire if there is only fingerprint ??
please explain how is different between fingerprint and feather.

Regards
jpanp


Top
 Profile  
Reply with quote  
 Post subject: Re: how to separate heated and unheated blue sapphire ??
PostPosted: Thu Jul 29, 2010 1:17 pm 
Offline
Site Admin

Joined: Thu Jan 05, 2006 4:27 pm
Posts: 1750
Hi jpanp,

Fingerprint and feather are indeed words describing the same thing. Properly called a partially healed fractures.

Heated and unheated sapphires are usually seperated by careful observasion with a gem microscope. There are various pointers to heating. broken rutile needles, fractures around crystal inclusions etc.

You say the only thing in the stone is a fingerprint. Are you sure there are no other inclusions? fingerprints / feathers / veils etc are also inclusions in synthetic flux grown sapphires where they are known as flux veils. These are generally opaque (yellow or orange) where natural veils are transparent to transluscent.

If there are NO other inclusions than the veil then I'd cheque extra carefully to ensure it isn't a flux synthetic.

other than that maybe more magnification and morecareful obsevations. Very few natural corundums have no inclusions in them.

Hope this helps

Frank


Top
 Profile  
Reply with quote  
 Post subject: Re: how to separate heated and unheated blue sapphire ??
PostPosted: Thu Jul 29, 2010 8:17 pm 
Offline
New to the Forum or The Quiet Type

Joined: Thu Jul 29, 2010 10:51 am
Posts: 3
Dear Frank,

Thank you for your answer.

I am sure that there are no silk, needle and crystal at all.
Only fingerprints, zoning and growth pattern.

So, how does fingerprint look after passed heat treatment.

Regards
Jpanp


Top
 Profile  
Reply with quote  
 Post subject: Re: how to separate heated and unheated blue sapphire ??
PostPosted: Thu Jul 29, 2010 11:45 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 21602
Location: San Francisco
Jpanp, what sort of background do you have in gemology?


Top
 Profile  
Reply with quote  
 Post subject: Re: how to separate heated and unheated blue sapphire ??
PostPosted: Fri Jul 30, 2010 4:27 am 
Offline
Active Member
User avatar

Joined: Tue Apr 07, 2009 12:57 pm
Posts: 96
Location: Mumbai, India
Hi Japnp,
I would say your stone is likely to be flux synthetic as Frank pointed out. Many compnies such as Ramaura, Chatham produce flux grown synthetic sapphires. Such stones can be only confirmed to be natural if u put it under advanced instuments such as the FTIR spectrometer etc.
However what I have usually seen in feathers in natural sapphires is randomly oriented liquid droplets which after heating usually look somewhat aligned. However this is not a sure-shot factor of identification and u have to rely on Zircon inclusions or undissolved rutile silk or sometimes two-phase inclusion to identify it as natural unheated stone.
I think the best thing for you to do would be to submit the stone in a recognised lab such as AIGS or GIA.
If you do not want to spend too much I think an AIGS e-certificate would be best option for you.

_________________
Exotic Gemstones: All Natural & Untreated
The Star Ruby Shop


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 11 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