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 5:25 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 19 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Synthetic Tsavorite
PostPosted: Mon Sep 25, 2006 4:25 pm 
Offline
Gemology Online Veteran
User avatar

Joined: Fri Jan 27, 2006 12:27 pm
Posts: 764
Location: Western NY
Check this out:

http://www.facetingrough.com/rough_synt ... rite.shtml

The page describes it as YAG-like, but without the Yttrium. I wonder if/how the lack of Yttrium affects the optical properties from an i.d./separation standpoint.

I also wonder how long this stuff has actually been available. Beware largish, exceptionally clean tsavos on eBay....

_________________
Peter Torraca, GG
gemcutter
http://www.torraca.net
<><


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Sep 25, 2006 4:31 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19886
Location: San Francisco
Curious.
Of course to be a synthetic tsavorite it must be chemically:Ca3 Al2 Si3 O12.

If it is anything else, it is an artificial product.
Does anyone want to research with facetingrough.com and ask them?


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Sep 25, 2006 4:34 pm 
Offline
Gemology Online Veteran
User avatar

Joined: Fri Sep 08, 2006 7:03 pm
Posts: 606
Location: Sweden
Well, I don't have the formulas in my head, but isn't synthetic spinel something quite different from natural spinel in chemical formula, although still considered a synthetic?

_________________
If it sounds good, then say it again!


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Sep 25, 2006 4:59 pm 
Offline
Active Member

Joined: Sun Nov 20, 2005 6:00 pm
Posts: 87
Location: northern ca
Here's a company that sells lab grown garnet.
http://morioncompany.com/Yttrium.htm


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Sep 25, 2006 5:00 pm 
Offline
Gemology Online Veteran
User avatar

Joined: Fri Jan 27, 2006 12:27 pm
Posts: 764
Location: Western NY
Jung Kee -- by definition, synthetic spinel has the same chemical composition as natural spinel. If it had a different chemical composition, it would be considered a simulant, not a synthetic. (This is true in gemology anyway; other fields may use the words "synthetic" and "simulant" differently.)

Barbra -- That's a good idea. I'll email Rob K. and see what he has to say. I've done business with him before and found him to be quite forthright and reliable.

_________________
Peter Torraca, GG
gemcutter
http://www.torraca.net
<><


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Sep 25, 2006 5:04 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19886
Location: San Francisco
Quote:
Well, I don't have the formulas in my head, but isn't synthetic spinel something quite different from natural spinel in chemical formula, although still considered a synthetic


As I understand, the ratios are different in natural vs. synthetic spinel, but the elements present are the same.
Natural spinel is MgAl2O4, which can also be written MgO Al2O3. In synthetic spinel the ratio is MgO to (5)Al2O3.


Last edited by Barbra Voltaire, FGG on Mon Sep 25, 2006 5:15 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Sep 25, 2006 5:14 pm 
Offline
Gemology Online Veteran
User avatar

Joined: Fri Jan 27, 2006 12:27 pm
Posts: 764
Location: Western NY
Thanks red dirt -- In digging through Morion's pages a little further, I found this: http://morioncompany.com/NewMaterials.htm Scroll down a little and note that they list the "emerald green" as GGG. I have no idea if it's the same stuff -- but I was surprised as how cloudy it looks in the images they supply.

Barbra -- I'm not a chemist, so I'm way out of my depth here -- but doesn't a different chemical formula mean a different structure and thus a different material? Is "synthetic spinel" more properly a simulant of spinel?

_________________
Peter Torraca, GG
gemcutter
http://www.torraca.net
<><


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Sep 25, 2006 5:15 pm 
Offline
Platinum Member
User avatar

Joined: Fri Feb 24, 2006 1:20 am
Posts: 2742
Location: Southern California, U.S.A.
Barbra Voltaire wrote:
As I understand, the ratios are different in natural vs. synthetic spinel. Natural spinel is MgAl2O4, which can also be written MgOAl2O3. In synthetic spinel the ratio is MgO to (5)Al2O3.


Barbra, which type of syn. spinel are you referencing? Flame-fusion or the flux-grown type?

Rick Martin


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Sep 25, 2006 5:16 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19886
Location: San Francisco
flame fusion

The structure is closely related to sapphire, but with a closely packed arrangement of O layers, producing a cubic crystal.

"Synthetic" spinel was stumbled upon while experimenting with flame fusion synthetic sapphire.


Last edited by Barbra Voltaire, FGG on Mon Sep 25, 2006 5:24 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Mon Sep 25, 2006 5:23 pm 
Offline
Platinum Member
User avatar

Joined: Fri Feb 24, 2006 1:20 am
Posts: 2742
Location: Southern California, U.S.A.
pt wrote:
note that they list the "emerald green" as GGG. I have no idea if it's the same stuff -- but I was surprised as how cloudy it looks in the images they supply.


Well gallium and gadolinium certainly aren't yttrium. When you write Rob why don't you ask him what the properties of his new "tsavorite" are? His copy about the stuff seems carefully wiggle-worded.

Rick Martin


Top
 Profile  
Reply with quote  
 Post subject: color-write
PostPosted: Tue Sep 26, 2006 1:51 am 
Offline
Platinum Member
User avatar

Joined: Wed Apr 26, 2006 12:44 am
Posts: 2051
Location: San Francisco
I live about .25 mile/3 min from Rob's shop. I've gotta get my loup back and i'll ask him about/pickup some of this material when I go over tomorrow. Should be interesting..


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Tue Sep 26, 2006 12:21 pm 
Offline
Gemology Online Royal Princess

Joined: Mon Oct 17, 2005 10:56 am
Posts: 6462
Location: The frozen north prairie :-/
You only have one loupe? :shock:


Top
 Profile  
Reply with quote  
 Post subject: Tanzanion
PostPosted: Tue Sep 26, 2006 5:27 pm 
Offline
Gold Member
User avatar

Joined: Wed Sep 06, 2006 1:15 pm
Posts: 1795
Location: canada
PT:

Thanks for the link on Tanzanite and Tanznion. :)

I have copied the stats on the two "gems " to my "book" :) Now I can test for the artificial if I see it.

The "book" eventually gets copied to a "flash card" that goes into a rolidex.
:D
As on gets ah .. more mature ... one needs memory aids lol

Thanks again

_________________
A Chinese proverb says "Gold is valuable, Jade is Priceless."


Top
 Profile  
Reply with quote  
 Post subject: the loup
PostPosted: Tue Sep 26, 2006 5:34 pm 
Offline
Platinum Member
User avatar

Joined: Wed Apr 26, 2006 12:44 am
Posts: 2051
Location: San Francisco
it's one of those 30mm diameter or so Schneider loupes... I kinda like it.. cause it's big... here's the link...

http://www.kassoy.com/ls10.html

I have others, but kinda like looking through a straw after that one..


Last edited by jleb on Tue Sep 26, 2006 5:59 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Tue Sep 26, 2006 5:55 pm 
Offline
Gemology Online Veteran
User avatar

Joined: Fri Jan 27, 2006 12:27 pm
Posts: 764
Location: Western NY
Actually Wolf, that sounds like a pretty good idea. What info. actually makes it to one of your index cards? How do you organize them?

_________________
Peter Torraca, GG
gemcutter
http://www.torraca.net
<><


Last edited by Peter Torraca on Tue Sep 26, 2006 8:03 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 19 posts ]  Go to page 1, 2  Next

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 0 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