July 11-12:BILLINGS, MONTANA: Annual show; Billings Gem and Mineral Club; Sat. 10-5, Sun. 10-4; Free admission!
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Sat Jul 04, 2020 8:20 pm

All times are UTC - 4 hours




Post new topic Reply to topic  [ 7 posts ] 
Author Message
 Post subject: Raman spectrometer
PostPosted: Wed Jan 30, 2008 3:44 pm 
Offline
Established Member
User avatar

Joined: Thu Jan 24, 2008 3:33 am
Posts: 19
Location: London, UK
Has anyone used a Raman spectrometer for rough gemstone identification in the field?

This one: http://www.deltanu.com/dn06/solutions/e ... .htm#rhmin

_________________
Pearlera


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Jan 30, 2008 6:18 pm 
Offline
Gold Member
User avatar

Joined: Mon Apr 16, 2007 12:05 am
Posts: 1467
From this recent thread, I would guess the answer is "no one here has used one."

They are quite pricey, but maybe you want to be a first adopter. Then the only difficulty is finding a comprehensive database of known gem material.

These spectrometers collect a spectrum that is of little diagnostic value on its own. You identify the gem by comparing its spectrum to a database of spectra of known material. If you don't find a matching spectrum, then well... at least you have identified what the gem isn't.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Jan 31, 2008 2:35 pm 
Offline
Valued Contributor
User avatar

Joined: Sat Jun 02, 2007 8:03 pm
Posts: 179
Location: N. Idaho
There are a few people using Raman spectroscopy in the lab but the units have gotten considerably smaller, Enwave makes the EZraman-M which is small and battery powered and sells for $13,950. My understanding is that this unit does an amazing job for the price.

As Brian indicated, the unit itself won't tell you much without access to a database, the best of which is the RRUFF project and it's free software, CrystalSleuth:
http://rruff.info/about/about_software.php

I've used it for powdered diffraction analysis but not for Raman data. It works for both.

I believe the RRUFF project has data on over 2000 mineral specimens. It was implemented under the direction of Dr. Bob Downs of the Geoscience Dept. at the University of Arizona and is a public project funded by a $5 million grant from the first CEO of Apple Computer, Mike Scott, who is a dedicated gem aficionado.

Here's a good resource for general mineralogical info:
http://www.ima-mineralogy.org/linktools.html

_________________
L. Bruce Jones, G.G., F.G.A., D.Gem.G.
Former Research Gemologist turned sub builder


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Jan 31, 2008 5:46 pm 
Offline
Platinum Member
User avatar

Joined: Tue Jan 02, 2007 8:20 pm
Posts: 2657
Unless you are an experienced lab rat I think you would be better off buying Martin Haske's Briefcase sized SAS2000 unit which starts about $18,000. It is designed to be used by non spectroscopists.

Interpreting a raw Raman spectrum and matching it to a database might be a bit of a challenge unless you have a background in spectroscopy. Raman is an advanced technique not a beginners.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Jan 31, 2008 10:50 pm 
Offline
Valued Contributor
User avatar

Joined: Sat Jun 02, 2007 8:03 pm
Posts: 179
Location: N. Idaho
Gene,

I'm not sure I agree. Bear Williams is using Enwave equipment successfully exclusively for gem work and I am sure there are others.

I intend to visit Eric Woo in Irvine where the equipment is manufactured and try it out first hand. They've just introduced a microscope with Raman capability. They'll be at AGTA in Tucson at booth 903 or 27 on the 8th and 9th of February giving demonstrations.

Today I ran down an electron microprobe for my basement lab and I have a powder diffractometer. I should be able to soon identify any mineral species on the planet. The Raman spectrometer and RRUF software should round out the package.

Of course, separating natural materials from synthetics and treated stones is another thing entirely. One instrument at a time...

_________________
L. Bruce Jones, G.G., F.G.A., D.Gem.G.
Former Research Gemologist turned sub builder


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Jan 31, 2008 11:12 pm 
Offline
Platinum Member
User avatar

Joined: Tue Jan 02, 2007 8:20 pm
Posts: 2657
Bear Williams has been using Ocean Optics spectrometers for years which is not a trivial matter. You are a labrat for sure. These things are getting easier to use and smaller but most of the people that use them or specify them have Ph.Ds (You almost have one of those too right?? And you have a powder diffractometer that you know how to use?? and a microprobe?? [wheredja get that ?? I have been trying to lay my filthy paws on one of these for years] The defendant is a labrat! I rest my case your honor :D )


BTW I forgot to mention that Marty makes a Raman version of the SAS2000.
Raises the price a bit though. I don't know how much.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Wed Mar 19, 2008 10:27 am 
Offline
Platinum Member
User avatar

Joined: Tue Jan 02, 2007 8:20 pm
Posts: 2657
http://www.enwaveopt.com/

Big sale Enwave Raman units $10,000

Don't crowd there are plenty for everyone. :lol:


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 7 posts ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 1 guest


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