Mindat Logo
bannerbannerbannerbanner
Welcome!

Atacamite

Posted by Erik Vercammen  
Atacamite
December 27, 2011 10:17AM
'Paratacamite' is not in the list of the polymorphs.
Re: Atacamite
December 27, 2011 10:56AM
    
And correctly so.

Although long considered as the rhombohedral polymorph of Atacamite, Paratacamite has been recently shown to contain essential Zinc, in part replacing Copper in one position and helping stabilize the trigonal cell. This prevents it from being a polymorph of Atacamite. In this context, it's the Cu-dominant analogue of Herbertsmithite, Haydeeite and Gillardite.

Lefteris.
Re: Atacamite
December 27, 2011 11:17AM
Lefteris,

Best wishes for 2012, and thanks for the info. It should be put on the atacamite page also, for this is new and a lot of amateurs like myself may have the same reaction about paratacamite being 'forgotten'.



Edited 1 time(s). Last edit at 12/27/2011 11:22AM by Erik Vercammen.
Re: Atacamite
December 27, 2011 02:22PM
    
Does Atacamite contain any Zn? If so what would be the maximum it could contain?
Re: Atacamite
December 27, 2011 03:04PM
    
Reiner - I don't know, I'm also one of the amateurs here.

If I remember correctly, it was Uwe Kolitsch that brought up the matter of Zn content in Paratacamite in a discussion some time ago, before the mindat page was updated. Maybe he would know.

However, I believe that the discovery and description of several new species in the Atacamite group recently, has brought some changes in the understanding of the crystal chemistry and structures within the group.

Lefteris.
Re: Atacamite
December 27, 2011 04:07PM
    
The reason I am asking is that I was wondering if semi-quantitative EDS would be useful for distinguishing Atacamite from Paratacamite. That would only work if Atacamite did not contain much Zn compared to paratacamite.
Re: Atacamite
December 27, 2011 10:42PM
    
Well, since Zn is essential in Paratacamite, no Zn at all would indicate Atacamite - especially if coupled with an orthorhombic xl form.

Lefteris.
Re: Atacamite
February 26, 2012 11:52AM
The name Atacamite does not come from Dimitri Golytsin in his ‘Recueil des noms par ordre alphabetique apropries en Minéralogie’, as stated in most sources, but stems from the german naturalist Johann Friedrich Blumenbach (1752 - 1840), who described and named it in his work 'Handbuch der Naturgeschichte, fünfte Auflage 1797 S. 660.'

[books.google.be]
Author:

Subject:


Attachments:
  • 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.
CAPTCHA
Message:
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: October 23, 2014 09:29:59
Mineral and Locality Search
Mineral:
and/or Locality:
Options
Fade toolbar when not in focusFix toolbar to bottom of page
Hide Social Media Links
Slideshow frame delay seconds