Arsenic

The first draft of the Best Minerals arsenic article is finished. Thanks to all who contributed to making this article better and especially to Paul De Bondt for his excellent article on the French Arsenic specimens. I didn't include the suggested US arsenic locality suggested and my fellow country men will probably riot in the streets and hound me out of mineral shows for the next ten years, but if one of them will supply a good picture of same, Ill relent and include it in the article.

Rock Currier
Crystals not pistols.

Rock, what a great piece of work!!! Thank you for putting it together. I think it shows the power of this Wiki procedure.

However, in my previous posting I mentioned that Antimony and Stibarsen remained tin white while Arsenic tarnished black. The photos from Brezovi Hori, Czech Republic show this well. The M Kampf photo (#8) shows the black mamillary Arsenic containing tin white layers of Stibarsen. (Below 300 C Sb is insoluble in As and the Sb sweats out as Stibarsen. Stibarsen is a little greyer than Antimony). The Jakub Jurasec photo (#7) is tin white and shows only Stibarsen or Antimony. Some localities, I don't know if this is one, produce all three minerals. Looking at the back of Jakub's specimen would tell the tale. If it is like M. Kampf's piece, it is stibarsen; but if it is all tin white, then it is either Antimony or Stibarsen and analysis is required. When analysed things like Paradocrasite etc. often show up. It is often worth checking Stibarsen pieces for these rarities, if you like having invisible species in your collection. Perhaps Jakub could comment.

Also Thomas Witzke's Schlema, Germany Arsenic photo (#30) is probably Arsenic. However, it may be an example of a pseudomorph after Arsenolamprite, the orthorhombic allotrope of Arsenic. The xls look prismatic and this is indicative. If they are long trigonal rhombohedra then they formed as Arsenic. However if they have a rectangular cross section, then they formed as Arsenolamprite and later pseudomorphed to Arsenic. I can't tell from the photo. Perhaps Thomas could comment.

Botryoidal Arsenic with Stibarsen and rarities came from the Engineer Mine, Atlin B.C. and grotti Arsenic came from Savona, B.C. I might be able to dig up some pictures. The Engineer material rates with some stuff posted here, but the Savona material, while intersting large lumps, is not the greatest. As a kid I found flecks of Native Arsenic, behind St Joseph's Oratory, on Mount Royal in Montreal. Montreal is a Dana Locality!!!

Edit: I just skimmed the article and looked at the photos when I made my last posting. I now see that you included the stuff on Stibarsen and Arsenolamprite. Thanks for that. When Thomas or Jakub reply I'll be happy to edit in their comments, if appropriate.



Edited 2 time(s). Last edit at 07/12/2009 04:44PM by Rob Woodside.

Great article, Rock.

There is a minor error in the locality string of the Vater Abraham mine: the Marienberg District is an individual mining district in the central Erzgebirge, not a sub-district of the Freiberg district (which is located in the eastern Erzgebirge).
May I also suggest that the mine is not referred to as having "delivered" specimens (otherwise I would have ordered ...)

Rob, I have numbered the images. Could you edit your recent comments above and stick in the image numbers that you are talking about?, and Ill make suitable changes in the text. I have started to experiment with numbering all the images in an article. It makes it easy to refer to exactly you want to draw attention to. However this works great for short articles with only a few images but the problem is that when you start to get a lot of images like this article, which still has a modest number of images compared to some of the others and even larger ones to come is that if you add or subtract an image then you should go in and change all the image numbers, and of course their references in the text. That on the big image articles can be a big job. Bob, any other images you can scare up for the article would be appreciated.

Peter, as usual, thanks for the corrections.

Rock Currier
Crystals not pistols.

Hi guys:

just to add that very good spheres or globular mamellonar Arsenic were found at Alacran Mine (Pampa Larga district), Copiapó, Atacama, Chile.

The I.Domeyko Mineral Museum, at La Serena (Chile), has 1 hand specimen with a 3 cm mammellonar xls perched on relic and massive arsenic.
This is a 1900 aprox sample: more recently, the best chilean Arsenic pieces came from an interesting find around 1990-1999: those samples were often asciated to radial steel-grey sharp bladed Arsenolamprite xls, Calcite, Stibnite, and minor Smithite.

Unfortunately no good foto of Arsenic mammellonar pieces are well represented on Alacran mindat gallery yet.

Maurizio Dini

Maurizio,
I don't find anything searching for Arsenic/Chile. Can you give me a URL?

Rock Currier
Crystals not pistols.

Krasnochikoiskoe deposit [www.mindat.org] is apparently the main producer of large native arsenic specimens in Russia - [www.mindat.org], [www.mindat.org], [www.mindat.org]

Abundant, but more small size arsenic (with minor admixture of stibarsen) specimens come from Bor mine in Dalnegorsk.

Pavel,
Could you tell us something about the Krasnochikoiskoe deposit? How big to the native arsenic specimens their get? What is the geology? What is the main production of the mine?s? Open pit? Still operating?

I have included the locality and two pictures of Arsenic from the deposit.

Rock Currier
Crystals not pistols.

Rob, I have included your remarks about the various arsenic specimens in the article. Thanks so much. If you can eventually find pictures of arsenic specimens from the Engineer mine we will include them.

Rock Currier
Crystals not pistols.

Dear Rock,
Krasnochikoiskoe deposit (Krasnochikoiskii priisk) was mined for placer gold as usually. Native arsenic was found occasionally and nobody need in it here. It form central parts (3-4 cm thick) of calcite veinlets some meters long.
Host rocks for arsenic/calcite veins are basic meta effusives. Sometimes they are strongly pyritized and this pyrite contain some of gold. So gold placers were formed over these basic rocks. Gold/pyrite mineralisation don't connected with nativie arsenic one. Moreover apparently native arsenic veins located in the less pyritized rocks. Of course gold placers are mined by open pits. As I find in internet they are exhausted and abandoned. All known to me arsenic specimens were collected in 60th-70th.

I'll upload native arsenic photos from Dalnegorsk, Belorechenskoe and Maiskoe deposits as soon I'll find specimens in my boxes.

Kind regards,
Pavel

Pavel,
Thanks, I have included your comments in the article.

Rock Currier
Crystals not pistols.

This is arsenic from Norilsk group deposit - [www.mindat.org]

Pavel,
I have placed the picture in the article. Can you tell us something about the mine and the geology and its history?

You can enter this kind of stuff directly into the articles if you like. Just let me know and Ill come along and if needed clean up the formatting and the English and bother you for more details if necessary. Thats a nice rich looking piece.

Rock Currier
Crystals not pistols.