December 14-16—SAN DIEGO, CALIFORNIA: Wholesale and retail show; Gem Faire Inc.; Scottish Rite Center, 1895 Camino del Rio S; Fri. 12-6, Sat. 10-6, Sun. 10-5
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Mon Dec 10, 2018 8:03 pm

All times are UTC - 4 hours




Post new topic Reply to topic  [ 3 posts ] 
Author Message
 Post subject: Two sapphires
PostPosted: Sat Mar 10, 2018 8:25 pm 
Offline
Moderator
User avatar

Joined: Mon Apr 02, 2012 9:31 pm
Posts: 3034
Location: North Carolina
So, in my continued exploration of microscopy I took a look inside two sapphires I bought last year at the Franklin gem shows. Both were very cheap, sold as part of a mixed lot with a variety of neat stones. No details or disclosures were provided with them--I suspect they were originally JTV purchases that someone picked up in an estate since a few of the gem jars had half-removed familiar-looking barcodes. I did use our raman to confirm they are both corundum. I am not sure what to look for to check for heat, but both do have fine intact rutile needles that seem promising.
Image
Image
The first stone is a nice light yellow 1 carat oval. It shows a pronounced golden sheen when viewed from the side. Click inclusion pictures for larger versions.
Image
Image
As you would guess the sheen seems to be provided by flat hematite/ilmenite crystals. They're irridescent through the scope but that is hard to pick up on camera. There are a few thin needles mixed in which I assume are minor exsolved rutile--they appear to be intact, which I'd guess is a good sign with regards to heat?
Image
The second one is a 1.18ct milky blue-violet pear.
Image
This one is shot through with these fine crystal(?) inclusions, with minor rutile needles in between. Again, the rutile appears to be intact. I did look at the stone under crossed polars using my gemoaid microscope kit, and they do show up bright against the dark corundum background which I assume indicates they're crystal inclusions that are repolarizing the light and not negative crystals?
Anyway, there is a lot to learn!


Top
 Profile  
Reply with quote  
 Post subject: Re: Two sapphires
PostPosted: Sat Mar 10, 2018 11:09 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19173
Location: San Francisco
Stephen, do you have an immersion style microscope you could view these saphs with?
A little methylene iodide could be insightful.


Top
 Profile  
Reply with quote  
 Post subject: Re: Two sapphires
PostPosted: Fri Mar 16, 2018 9:22 am 
Offline
Gemology Online Veteran
User avatar

Joined: Wed Dec 30, 2009 11:44 am
Posts: 519
Location: PAKISTAN-Peshawar
To me both are unheated

_________________
Gemology for everyone.
HUK


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