Discussions

💬 Home 🔎 Search 📅 Latest

╳Discussions

💬 Home 🔎 Search 📅 Latest

Groups

Recent Images in Discussions

Improving Mindat.orgsiderazot is fiction?

25th Aug 2007 01:28 UTCPavel Kartashov Manager

Dear friends!

It seems to me, that most of specimens of siderazot don't contain it. I had analysed some specimens which looks exactly like as on the photo http://www.mindat.org/photo-9263.html . I was unable not only to confirm siderazot presence on them, but even presence of any iron-rich mineral on theyr surfaces! Even magnetite, hematite or goethite as films or microgranular layers... This metallic lustre is some optical effect in the glass!

Have anybody analytical confirmation of siderazot existence in his specimen? Or nobody met it from 1876?

I have strong impression, that this "grandfathered mineral" is simple analytical error. And this error is advantageous only for specimen sellers.

Exist any article with results of natural siderazot investigations by any of modern analytical method?

Regards,

Pavel

25th Aug 2007 13:57 UTCJean-Francois Carpentier Expert

I had so far in hands two specimens supposed to be siderazot but EDX analysis did not show actually any of the supposed elements; I do also suspect as Pavel that most of those samples proposed all over the web are not genuine siderazot and show only glassy optical effects. Till someone demonstrates we're wrong, of course.

regards

jean-francois

25th Aug 2007 14:31 UTCMaurice de Graaf Expert

EDX is not the best method for finding nitrogen, so it is inadequate to prove the existence of Siderazot.

I have no idea if Pavel is right or not, if there is any Siderazot at all on this planet. I strongly agree with him that by far most Siderazot specimen I have seen, just seem to be thin films of iridiscent iron oxides on lava. I had this discussion earlier somewhere else and made picture http://www.mindat.org/photo-19222.html This is my supposed Siderazot specimen. Here the blue coloration is very local and it sits on non iridiscent matrix. But this specimen is also not analyzed, but to me it at least looks more plausible. Pavel, I can provide you with a sand grain size sample from this specimen if you can analyze it correctly. Send me a mail about it.

Maurice

25th Aug 2007 17:59 UTCJean-Francois Carpentier Expert

I agree that EDX is not appropriate for N analysis; on the other hand, these blue iridiscence coatings do not necessarily call for iron oxides as in the two specimens I analyzed (which apparently looked somewhat different to those in , as the blue color was not so obvious), Fe was a very minor component. I personally always try to evaluate first heavy elements with EDX, which allows for a fast preliminary - though discriminating - screening.

25th Aug 2007 18:37 UTCPavel Kartashov Manager

Our microprobe JSX-3202M able to detect nitrogen in phases where it really present, in osbornite for example, or in salmoniac, or in barberiite. Qualitatively of course, because we haven't good etalon for N up to now. I can't to obtain coarsecrystalne BN for etalon preparation, only a dust or microporous ceramic.

By the way, siderazot is iron rich compound - 90.88 % Fe and 9.12 % N. It is high-iron and oxigen-free phase and MUST be well visible in BSE or in COMPO regime.

I had check also bright-blue films from Tolbachik basalts too. They are high-iron but contain oxigen. So they can't to be siderazot. But on Vezuvius specimens I don't found even Fe-rich phases.

Maurice, you can to sent your siderazot grain to my institute address and I'll check it on N content.

25th Aug 2007 19:12 UTCŁukasz Kruszewski Expert

Seems like its time to analyze my "siderazot" (-; I was able to detect nitrogen in sal ammoniac and some NH4+ - bearing sulphates, by EDS (semi-quantitative, of course).

31st Aug 2007 19:43 UTCUwe Kolitsch Manager

Comment added to siderazot page.

20th Nov 2012 21:38 UTCJeff Weissman Expert

ANy follow-up to this interesting thread?

thanks, Jeff

23rd Nov 2012 21:41 UTCŁukasz Kruszewski Expert

It should not be a problem to check the presence of nitrogen by EDS in case of nitrides, as N is strongly bonded in these compounds. I have a sample of "siderazot from Etna", of course the bluish thingies covering the surface of lava vesicles have no N and, as far as I remember, also Fe...

23rd Nov 2012 23:52 UTCJeff Weissman Expert

The type description for siderazot gives the mineral as being silver metallic, so I am not surprised that the bluish material is something else.

Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2024, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: May 4, 2024 00:30:08

Go to top of page