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 Fri Mar 29, 2024 2:24 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 32 posts ]  Go to page 1, 2, 3  Next
Author Message
 Post subject: Aquamarine blue obsidian - does it exist?
PostPosted: Sun Oct 23, 2005 6:22 am 
Offline
Moderator

Joined: Sun Oct 16, 2005 12:42 pm
Posts: 2846
Location: Ho Chi Minh City, Vietnam
I was in a mineral and gem shop this past summer :shock: , and the people who owned it were selling beads and jewelry of what they had been told was obsidian. The lady wasn't sure of the origin and was waiting for more information on it from her dealer. I have also seen the same being sold as aquamarine in Turkey.

However, it looked remarkably like this:

http://www.prettyrock.com/php/facet-rough-detail.php?q=color&v=blue&item=1513&type=facet-rough

So, does it exist in nature, or is this lab glass being sold as obsidian?


Last edited by Julie Gowans-Poli on Sun Oct 23, 2005 7:51 am, edited 1 time in total.

Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Oct 23, 2005 7:19 am 
Offline
Gemology Online Veteran
User avatar

Joined: Mon Oct 17, 2005 1:06 pm
Posts: 718
Location: Bangkok, Thailand
Hello,
I never heard about this color to be a natural color, and then I dont have seen anywhere on this page that this piece of glass is supposed to be natural... So it is probably not natural.

All the best,

_________________
Vincent Pardieu

www.fieldgemology.org
www.conservationgemology.org

The views expressed here are V. Pardieu’s opinions and do not necessarily reflect those of GIA Laboratory Bangkok (http://www.giathai.net)where he is an employee since Dec 2008.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Oct 23, 2005 7:48 am 
Offline
Moderator

Joined: Sun Oct 16, 2005 12:42 pm
Posts: 2846
Location: Ho Chi Minh City, Vietnam
The page showing the picture lists it as lab glass.

The lady in the store this summer said that her dealer had claimed it was obsidian, but she couldn't remember where it was supposed to have been from. She thought maybe China, and was waiting on more information about it from her dealer.

I doubt very much that it is natural as well, since it was very very clean, although I have run across a reference on the internet to "green/blue obsidian" qualified with "not sure if it's natural or not".

http://www.gemcutter.com/cut03.htm , go down to the obsidian section.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Oct 23, 2005 11:58 am 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 21602
Location: San Francisco
I've not seen any reference in the literature to blue obsidian. One would think that if it existed G&G or Gem-A would have reported on it. :?


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Oct 23, 2005 12:49 pm 
Offline
Moderator

Joined: Sun Oct 16, 2005 12:42 pm
Posts: 2846
Location: Ho Chi Minh City, Vietnam
From the GemCutter site:

Quote:
The following pieces were sold to us as obsidian from China. Their SG and RI are consistent with natural glass, and I have consulted with other gemologists on these: the consensus is that they are almost "too clean to be natural", but there is every other indication that they are natural, which means they fit a very narrow range of physical characteristics common to natural glass that is very difficult to duplicate with manufactured glass. The GIA does have record of blue obsidian, so we have found no reason to dispute the claim that they are natural obsidian.


The stuff that I saw looked exactly like the lab glass in the first link that I provided. Maybe the blue obsidian that the GemCutter people are referring to above "GIA does have record" isn't the same colour of blue?


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Oct 23, 2005 1:37 pm 
Offline
Valued Contributor

Joined: Sun Oct 16, 2005 4:25 pm
Posts: 161
Location: Michigan, USA
There is mention of electric blue obsisdian on http://www.cst.cmich.edu/users/dietr1rv/obsidian.htm which doesn't give detail but the fact that the page is by R. V. Dietrich and revised 6/05 makes me think the stuff exists EXCEPT further references (like on mineral galleries http://mineral.galleries.com/minerals/mineralo/obsidian/obsidian.htm) refer the the blue color as a sheen. Dietrich does not clarify this.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Oct 23, 2005 1:44 pm 
Offline
Moderator

Joined: Sun Oct 16, 2005 12:42 pm
Posts: 2846
Location: Ho Chi Minh City, Vietnam
I just came across this website offering rough:

http://www.triplearockshop.com/obsrough.html

but it's not at all the same thing.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Oct 23, 2005 10:57 pm 
Offline
Valued Contributor
User avatar

Joined: Wed Oct 19, 2005 12:10 am
Posts: 137
I would say it is almost certainly glass, not Obsidian. It is far too clean in that massive size to be obsidian, and I have never seen it blue either. But cheap all the same for a facetor who wants to practice cutting whoppers.

I also agree with Vincent – that even if it was obsidian, it is a mineraloid - not a mineral, and although in it's natural state can be interesting, as a gem cannot really be differentiated from cut glass, in beauty, durability or value.

_________________
I always arrive late to the office, but I make up for it by leaving early...

Martin


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Oct 27, 2005 6:51 am 
Offline
Gemology Online Veteran
User avatar

Joined: Fri Oct 21, 2005 12:33 pm
Posts: 708
Location: Gemologist/dealer & author
Oddly enough yesterday a client walked into my office with a suite of blue obsidian. A large faceted octagon an a smaller matched pair. I have never seen it before but I recalled this thread.

The stones were pretty much aquamarine blue with a bit of gray mask. They were quite clean, loupe clean.

_________________
Author: Secrets Of The Gem Trade, The Connoisseur's Guide (2nd Edition) http://www.secretsofthegemtrade.com and The French Blue: http://www.thefrenchblue.com[/url]:


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Oct 27, 2005 8:02 am 
Offline
Moderator

Joined: Sun Oct 16, 2005 12:42 pm
Posts: 2846
Location: Ho Chi Minh City, Vietnam
Did you get any information about where they got them?

Did it look anything like this? These guys are more of the unheated aquamarine colour.

Image

Image


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Oct 27, 2005 8:13 am 
Offline
Gemology Online Veteran
User avatar

Joined: Fri Oct 21, 2005 12:33 pm
Posts: 708
Location: Gemologist/dealer & author
Nuck,
These were darker in tone and not at all greenish. Don't know the source as the client really had no idea. Given its composition seems like obsidian should be available (theoretically) in any color.

The stones were for sale though I didn't ask the price. For me Obsidian ranks right up there as a gemstone, maybe just behind copralite. If you are interested I could enquire.

_________________
Author: Secrets Of The Gem Trade, The Connoisseur's Guide (2nd Edition) http://www.secretsofthegemtrade.com and The French Blue: http://www.thefrenchblue.com[/url]:


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Oct 27, 2005 8:25 am 
Offline
Moderator

Joined: Sun Oct 16, 2005 12:42 pm
Posts: 2846
Location: Ho Chi Minh City, Vietnam
Well, I should be back in Corsica at Easter, so I will definately go and ask this lady if she got more information on it or not.

I'm not really looking to buy any, I'm just really curious to know if there is really such a thing, or if this is some dealer passing lab glass off as obsidian.

Copralite, hmmmmmm so tempting. :lol:


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Oct 27, 2005 8:30 am 
Offline
Moderator

Joined: Sun Oct 16, 2005 12:42 pm
Posts: 2846
Location: Ho Chi Minh City, Vietnam
I had to look that one up, so for the benefit of anyone else who doesn't know what copralite is:

http://scienceviews.com/photo/library/SIA0651.html


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Oct 27, 2005 9:10 am 
Offline
Active Member

Joined: Mon Oct 17, 2005 9:28 am
Posts: 61
Location: Ontario, Canada
africanuck wrote:
I had to look that one up, so for the benefit of anyone else who doesn't know what copralite is:

http://scienceviews.com/photo/library/SIA0651.html


:lol:

_________________
David L


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Oct 27, 2005 10:27 am 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 3:36 pm
Posts: 192
Location: San Francisco
Quote:
Obsidian ranks right up there as a gemstone, maybe just behind copralite.

:shock: That's funny!!! :lol: :o :D

_________________
"Do well and you will have no need for ancestors" Voltaire


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 32 posts ]  Go to page 1, 2, 3  Next

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 25 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