Paulkerrite?

Hi,
are you sure about the paulkerrite? is the sample analysed?
[www.mindat.org]
Sorry, but i have my doubts.
Im my opinion, the most probable is to be phosphosiderite.


Cheers,
Pedro Alves



Edited 1 time(s). Last edit at 11/28/2011 09:37PM by Pedro Alves.

which photo ?

Most probably you are right, Pedro.
Ciao.

The photo is so bad that how can you know?

Reiner,
the photo is useless. My proposal is based on typical association (benyacarite + phosphosiderite) and, described by the photo's author, an usual phosphosiderite habit.

Sorry but, for me, the paulkerrite (at Folgosinho) is not proved yet...

Cheers,
Pedro Alves



Edited 1 time(s). Last edit at 11/29/2011 02:04PM by Pedro Alves.

Is this article in error?

Schnorrer, G. & Tetzer, G. (2005): Paulkerrite, K(Mg,Mn)2Fe2Ti[(OH)3|(PO4)4]×15H2O from Folgosinho quarry in Portugal, an additional locality for this rare compound. Aufschluss 56, 258-260. (in German).

Best Wishes, Van King

Dear van,
i have a great respect to the authors, but in the article above i can't find any reference to the techniques used to identify the species or results.
In this case, can we assume that as a credible reference?

Cheers,
Pedro Alves



Edited 1 time(s). Last edit at 11/29/2011 05:49PM by Pedro Alves.

Are you saying you think all paulkerrite is benyacarite, Pedro?

I agree on the picture btw.

Greetings from France,

Eddy

dear Pedro,

Glad to know that the identification appears to be a guess rather than supported by data. perhaps it was merely x-rayed?

Best Wishes, Van King

Message sent.

"... but in the article above i can't find any reference to the techniques used to identify the species or results."

Schnorrer usually analysed minerals by SEM-EDS and PXRD.
I will check the article.

BTW The formula given at Mindat seems to be 2 positive charges away from being balanced, unless they meant H₃O.

Best Wishes, Van King

Eddy,
«Are you saying you think all paulkerrite is benyacarite, Pedro? » No, that is something i can't assure. But, in my experience, all the probable 'paulkerrite' analysed turned out to be Benyacarite.

Cheers,
pedro Alves



Edited 2 time(s). Last edit at 12/21/2011 12:33AM by Pedro Alves.

Pedro, I am working on some specimens from Folgoshino (of Chiappino) searching possible paulkerrite crystals...
I will inform about the results.
Ciao.

Ciao Marco,
many thanks in advance.
I'm working on an article about Folgosinho, that will be helpfull (for all).

Ciao,
Pedro

OK Pedro,
I will pass the results as soon as they will be closed.
Ciao. Marco

Please keep me posted guys.
And if you need more specimens, I have plenty.

Greetings from France,

Eddy

Eddy,
please can you send to me just one small specimen?
My address is:
Marco Ciriotti
via San Pietro, 55
I-10073 Devesi-Ciriè (Italy)

I will analize (EDX + SC-XRD, if necessary).
Thank you very very much.
Cheers. Marco

Will do Marco.
Will ship on monday morning.

Greetings from France,

Eddy

I checked the Schnorrer & Tetzer (2005) article.
Roughly translated it says "X-ray and chemical studies led to the identification of ... paulkerrite". No details are given, however, on either techniques used or results of the chemical analyses (such as approximate formula, impurity elements, homogeneity, ...).
The article notes that the xls are colour-zoned (pale and dark yellow) and states "presently ... it is unclear if one of the zones corresponds to benyacarite or not".

So there are clearly some open questions.

Thank Eddy and thank you Uwe.
I will inform about the quantitative INCA SEM-EDX results of the Eddy specimen etc.