August 24:—SAN ANTONIO, TEXAS: Retail show; Southwest Gem and Mineral Society of San Antonio; Sat. 10-5
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Mon Sep 23, 2019 11:34 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 6 posts ] 
Author Message
 Post subject: petrographic polarizing microscopes review (old models)
PostPosted: Thu Dec 16, 2010 3:32 pm 
Offline
Gold Member

Joined: Sun Jun 28, 2009 9:56 am
Posts: 1219
http://www.microscopy-uk.org.uk/mag/ind ... polar.html

powerful identification tool for rocks and minerals (working from thin rock section or mineral powder). Not that easy to use (theory+practice needed)


Top
 Profile  
Reply with quote  
 Post subject: Re: petrographic polarizing microscopes review (old models)
PostPosted: Fri Dec 17, 2010 12:01 am 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19837
Location: San Francisco
It is my understanding, most universities in the US do not even teach optical mineralogy anymore. :(
Thin sections, sadly, are heading in the same direction as the typewriter.


Top
 Profile  
Reply with quote  
 Post subject: Re: petrographic polarizing microscopes review (old models)
PostPosted: Fri Dec 17, 2010 2:05 am 
Offline
Gold Member
User avatar

Joined: Mon Apr 16, 2007 12:05 am
Posts: 1454
We have no course focused solely on optical mineralogy, but optical techniques are a topic covered in the mineralogy course. We have the petrographic microscopes and case upon case upon case of thin-sectioned rocks. We even have the saw to cut the thin sections. The mineralogy course has a lab component, so the students do get exposure to the optical techniques.


Top
 Profile  
Reply with quote  
 Post subject: Re: petrographic polarizing microscopes review (old models)
PostPosted: Fri Dec 17, 2010 11:20 am 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19837
Location: San Francisco
I'm glad to hear it.

I'm a member of the MSA boards and I hear a lot of complaining about the fact that thin sections are simply not as revered as they once were, when I was a lass. :)

I guess the sophistication of other methods of identification have played a large part. Although, I see nothing as cost effective as a thin section.


Top
 Profile  
Reply with quote  
 Post subject: Re: petrographic polarizing microscopes review (old models)
PostPosted: Fri Dec 17, 2010 2:04 pm 
Offline
Platinum Member
User avatar

Joined: Tue Jan 02, 2007 8:20 pm
Posts: 2656
Perhaps there will be a "rediscovery" of them. In an analogous way the making of thin biological sections which used to be taught even in better high schools, but certainly at any university biology department, went out of fashion for a few decades, only being taught at programs specifically aimed at clinical pathology labs.

But now the U where I work has hired a guy who describes himself as a Histologist and he had me overhaul all the old microtomes in the store room and the other day I walked into his lab and it was like a bunch of kids dyeing Easter eggs. About ten students staining sections that they had cut. I had never seen such a thing even when I was an undergraduate about the same time Barbra was. (although I never used a microtome I DID use an ULTRA microtome for the transmision electron microscope as an undergrad)

Both techniqes are so basic that they can't be allowed to be forgotten.


Top
 Profile  
Reply with quote  
 Post subject: Re: petrographic polarizing microscopes review (old models)
PostPosted: Sat Dec 18, 2010 12:33 pm 
Offline
Gold Member

Joined: Sun Jun 28, 2009 9:56 am
Posts: 1219
I have yet to learn the basics of the polarizing mirocoscope but it sounds like a great tool. I'm not much interested in thin rock sections (good thing considering that the cutting equipment is expensive). Actually I'm mainly interested in the identification of rough minerals in powder form and I was told that one needs much less than one cube millimeter of powder to achieve identification, so I wouldn't really qualify this technique as destructive. The one thing that stops me from experimenting with it is the price of those scopes.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

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