Mindat Logo

Tremolite or diopside Franklin Quarry

Posted by Modris Baum  
Tremolite or diopside Franklin Quarry
January 10, 2012 05:25PM
This is a "talk page" thread. Click on the topic header at the top of the page to see the photo.

OK. I admit it. After neary 40 years of collecting I still can't tell amphiboles from pyroxenes. (But at least I don't sleep with a teddy bear.)

So it should be easy for the rest of you - right?

Shape wise, this looks like a lot of the tremolite from this quarry. But the latter is mostly dark silvery/gray, rather dull and opaque, and fluoresces very bright pale blue. But that's not always the case.

As for diopside - I never "knowingly" found any here. But it's supposedly common and can have a similar UV response (blue or yellow).

This particular xl fluoresces a moderate greenish yellow.

In any case, it's the only example I ever found that looks like this.

Edited 1 time(s). Last edit at 01/10/2012 06:16PM by Modris Baum.
Re: Tremolite or diopside Franklin Quarry
January 10, 2012 09:25PM

A rule of thumb lies in the fluorescence. The bright baby blue fluorescent material is almost always diopside. The greenish yellow or greenish blue fluorescent stuff is usually tremolite. Since there are pseudomorphs of tremolite after diopside, the crystal morphology is not an accurate guide in many cases.

Re: Tremolite or diopside Franklin Quarry
January 10, 2012 09:34PM
Modris, looks like the typical tremolite and you described its fluorescence correctly. Some of these crystals can be lighter colored or almost white and some can look almost black when there is heavy graphite inclusions in the tremolite.
Re: Tremolite or diopside Franklin Quarry
January 10, 2012 11:20PM
Thanks Chet and Steve - I was hoping you would take the "bait".

I think I get it now - at least for Farber. But I still can't tell amphiboles from pyroxenes sad smiley

Re: Tremolite or diopside Franklin Quarry
January 10, 2012 11:24PM
BTW Steve,

Now I know why so much of the tremolite at Farber looks silvery gray! I guess it should have been obvious.

But why is it that this sort of tremolite is the kind that has the most intense pale blue SW response? I mean really, really bright.
Don't tell me it's really still diopside - with graphite inclusions. Or better - do tell me if that's the case!

Thanks - Modris

Your Email:


  • Valid attachments: jpg, gif, png, pdf
  • No file can be larger than 1000 KB
  • 3 more file(s) can be attached to this message

Spam prevention:
Please, enter the code that you see below in the input field. This is for blocking bots that try to post this form automatically. If the code is hard to read, then just try to guess it right. If you enter the wrong code, a new image is created and you get another chance to enter it right.
Mineral and/or Locality  
Search Google  
Copyright © Jolyon Ralph and Ida Chau 1993-2014. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them. Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of thousands of members and supporters. Mindat does not offer minerals for sale. If you would like to add information to improve the quality of our database, then click here to register.
Current server date and time: December 18, 2014 23:10:06
Mineral and Locality Search
and/or Locality:
Fade toolbar when not in focusFix toolbar to bottom of page
Hide Social Media Links
Slideshow frame delay seconds