Davidite-(Ce) & (La)

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Can you help make this a better article? What good localities have we missed? Can you supply pictures of better specimens than those we show here? Can you give us more and better information about the specimens from these localities? Can you supply better geological or historical information on these localities?


Davidite-(Ce)
(Ce,La)(Y,U,Fe)(Ti,Fe)₂₀(O,OH)₃₈ trigonal


Davidite-(La)
(La,Ce)(Y,U,Fe)(Ti,Fe)₂₀(O,OH)₃₈ trigonal
Pavel Kartashov suggests a better formula for the species might be: (LREE,Ca)(U,Y,HREE,Sc)(Fe²⁺,Mn2+,Fe³⁺)₂(Ti,Fe³⁺,Cr,Nb,Al,V)₆Ti₁₂O₃₈ where LREE may be La,Ce or Ce,La in davidite-(La) or -(Ce)



Davidite, especially Davidite-(La) is by far the most common and abundant member of the Crichtonite group of menials which include Landauite, Loveringite, Crichtonite, Senaite, Mathiasite, Lindsleyite, Gramaccioliite-(Y) & Cleusonite. Aparently Romanite is also now a member of the group and previously many misidentified Davidites were called Romanites. Davidite-(La) is the only member of the group that is mined commercially because of its Uranium content like in eastern Siberia and Australia. Davidint-(Ce) is much rarer than Davidine-(La) but can still form crystals of substantial size like at the Tuftin pegmatite in Norway which occur in elongated masses to 20 cm with rough semi-linear outlines. Davidite-(La) is hexagonal and commonly metamict and has been found in rough flattened crystals as large as 30 cm.¹. Of course you can't tell the difference between the two species without a chemical analysis and often because of their metamict nature and somewhat variable chemistry it is sometimes difficult to assign a species name correctly.
1. Handbook of Mineralogy, Anthony, Bideaux, Bladh, Nichols. Vol.III, p158


Davidite
Australia
South Australia, Olary Province, Plumbago Station, Billeroo Mine, Radium Hill & others



The Radium Hill locality is claimed to be the type locality for both Davidite-(Ce) and Davidite-(La)¹
1. Mark Willoughby communication 2009.
We need someone to tell us about the Davidite specimens from this locality.


Davidite
Australia
South Australia, Olary Province, Plumbago Station, Billeroo Davidite Prospect

Davidite, largest is ~4cm	©

Davidite-(La)
Kazakhstan
Qaraghandy Oblysy (Karaganda Oblast'), Beqtau-Ata (Bektau-Ata)

Davidite-(La) 1.5 cm across	© Martins da Pedra

We need someone to tell us about the Davidite specimens from this locality.


Davidite-(La)
Mozambique
Tete district, Mavusi at Matema & Campangula



In very large rough crystals as large as 30 cm?

We need someone to tell us about the specimens from this locality.



Davidite-(Ce)
Norway
Aust-Agder, Iveland, Iveland, Frikstad (Frigstad), Tuftane (Tuftan; Tuptane)




This locality is considered the type locality for Davidite-(Ce) in Russian literature.¹
1. Pavel Kartashov sites: Neumann, H. & Sverdrup, T.L.(1960): Contributions to the mineralogy of Norway No. 8. Davidite from Tuftan, Iveland. Norsk Geologisk Tidsskrift 40: 277-288.

We need someone to tell us about the Davidite-(Ce) specimens from this locality.


Davidite-(La)
Spain
Badajos
A very important locality for davidites is Badajos in Spain. Very complex and nice twins are known from here, unfortunately their sizes are only up to 2 mm. Also davidites from here are very rich by Cr, V and Sc.¹
1. Pavel Kartashov, email 2009.


We need some pictures of these specimens and someone to tell us more about the specimens and loclaity.

Davidite-(La)
Switzerland
Grischun (Grisons; Graubünden), Vorderrhein Valley, Tujetsch (Tavetsch)

Davidite-(La) FOV 4mm	© Stephan Wolfsried

We need someone to tell us about the Davidite specimens from this locality.


Davidite-(La)
Zambia
North-Western Province, South East Solwezi, Luswishi River



We need someone to tell us about this locality and the Davidite specimens it produces.



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Rock Currier
Crystals not pistols.



Edited 16 time(s). Last edit at 03/24/2012 11:49PM by Rock Currier.

Good crystals occur in the Olary area. SAust - I will find some pictues & info

Regards,
Ralph

Thanks Ralph,
I am slowly working my way through the A minerals, reducing the size of the images a little and bringing all the images into the articles and incorporating the suggestions of contributors into the articles. It is slow going but eventually Ill get through the As and move on to others like this one.

Rock Currier
Crystals not pistols.

Hi Rock,
we should state, that davidites are the most usual and widespread members of krichtonite group. Only davidite-(La) able to form real industrial deposits, where it is the main ore mineral of U (E. Siberia, Australia).
From other hand, davidite-(La) is MUCH MORE abundant and widespread in comparison with davidite-(Ce), which is significantly more rare mineral (but sometimes it able to form large monomineral masses - Tuftan pegm., Norway).

Kind regards,
Pavel



Edited 1 time(s). Last edit at 04/22/2009 05:26AM by Pavel Kartashov.

Pavel, Sounds like something that should be in the article.

Rock Currier
Crystals not pistols.

I may be wrong here, Rock, but I think that the best crystallized specimens do come out of Australia. If Ralph doesn't send a pic, I will . I have a crackerjack xl that I got via a museum over there.

Howdy Rock and others,

Ralph is right about the best crystals coming from South Australia.
The best crystals come from, The Billeroo prospect, Billeroo Hill, Plumbago Station, Olary Province, South Australia.
Also, Radium Hill mine, Radium Hill area, Mingary, Olary Province, South Australia, Australia, is the type locality for both Davidite-(Ce) and Davidite-(La)
It should also be noted that, Tuftane (Tuftan; Tuptane), Frikstad (Frigstad), Iveland, Aust-Agder, Norway, is a 'Dana' listing not a TL listing.
I'll also add some photos as soon as I can.

Cheers Mark.

I'm sure Ralph will find some good pictures for the article. I'm sure he doesn't want to be banished from Australia for overlooking the find davidite specimens from there. Thanks for your input. Ray, we may take you up on that offer of a good photo.

Rock Currier
Crystals not pistols.

By the way, do you saw large and complete davidite-(La) xls from Zambia? I saw only photo in C. Gramaccioli's book "Radioactive minerals" or something similar (in Italian). But this photo almost killed me. ::o

What about TL of davidite-(Ce), Tuftan is listed as its TL in all literature in Russian (after the article Neumann, H. & Sverdrup, T.L.(1960): Contributions to the mineralogy of Norway No. 8. Davidite from Tuftan, Iveland. Norsk Geologisk Tidsskrift 40: 277-288). By the way no one Australian locality mentioned in locality list [www.mindat.org]

Besides that I have many doubts, that 'mavudzite' from Mozambique is davidite-(Ce). Rather it is davidite-(La) as usually, but with old analysis with 'sumCe₂O₃'=LREE and 'sumY₂O₃' =Y+HREE. But in this 'sumCe₂O₃' La is dominant rare earth.

Ray and Mark (and Pavel)
Billeroo is the location I had in mind - you both may have better crystals or images than mine, so please upload them. There was an article in the ANZ Mineral collector recently on the location.
I note the Olary specimens on Mindat are mostly listed as Davidite-(La), but one is labelled Davidite-(Y) (http://www.mindat.org/photo-140486.html). None are labelled Davidite-(Ce); I have not analysed any or seen any published analyses - any references welcome.
Ralph.

Regards,
Ralph

Davidite-(Y) is obvious misunderstanding. The initial "yttrodavidite" from Vishnevye Mts was Y-bearing (~11 mas.% of Y₂O₃ from total (REE+Y)₂O₃) davidite-(La). "Yttrodavidite" isn't a mineral, but variety, which was described before solution of crystal structure of the mineral, which demonstrated, that LREE and Y are located in different crystallochemical positions.
"Davidite-(Y)" is impossible combination of the mineral name and the suffix. Davidite-(LaY) is probable one, but after changing of whole crichtonite group nomenclature.
So the suffix was given to "davidite-(Y)" mechanically, before Gatehouse's works on the group, i.e. without deep understanding of crichtonite group systematic and their real compositions.



Edited 1 time(s). Last edit at 04/15/2009 12:39AM by Pavel Kartashov.

By the way, more proper formula of davidite is (LREE,Ca)(U,Y,HREE,Sc)(Fe²⁺,Mn²⁺,Fe³⁺)₂(Ti,Fe³⁺,Cr,Nb,Al,V)₆Ti₁₂O₃₈ where LREE may be La,Ce or Ce,La in davidite-(La) or -(Ce).

Besides that, very important locality for davidites is Badajos in Spain. Very complex and nice twins are known from here, unfortunately their sizes are only up to 2 mm. Also davidites from here are very rich by Cr, V and Sc. Davidite is davidite-(La) of course.

Again it looks like Pavel is going to save my bacon in this article. Lord only knows how big a fool I would have made of myself. Hopefully I won't have to rewrite it as many times as I did the one on Aluminum.

Rock Currier
Crystals not pistols.

Gramaccioliite-(Y) and cleusonite - two previous varieties of senaite - also are crichtonite group members now.
Romanite also belong to the crichtonite group. Moreover many romanites were described initially as davidites.



Edited 1 time(s). Last edit at 04/22/2009 07:04PM by Pavel Kartashov.

[www.mindat.org] - apparently this is the locality of giant davidite xls from Zambia.

Heres one....Joe


[www.mindat.org]

and another....hope these help...Joe

[www.mindat.org]

There are 3 pictures of Davide crystals from the Billeroo Prospect on mindat but does anyone know if that location produces Davidite-Ce, Davidite-La or both? One of the photos is labelled as Davidite-Y but, according to Pavel, that is most probably an error. John S.

Rob Lavinski tells me he just got in a lot of Davidite crystals from the Zambian locality and that he will soon upload some pictures for us.

Rock Currier
Crystals not pistols.

Here's a Davidite crystal I recently obtained from an Italian dealer. It is 4.7 x 4.1 x 3.9 cm; 91.5 grams. A perfectly formed rhombohedral floater. This was found in 1971 at the Ncinke Deposit, Luswishi Dome, Zambia. It was in the collection of the original geologist who studied the deposit. Radioactivity came in at 836 CPM.

Rudy