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Tungsten

Posted by Rob Woodside  
avatar Tungsten
October 04, 2009 07:07AM
ca    
Click here to view Best Minerals T and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.


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?

Below are some preliminary notes I have made about Tungsten. This entry and thread has been made as a place holder for information that you will hopefully contribute about Tungsten. It should be in no way be thought of as a claim I have staked out to write about this mineral, and in fact is an invitation for someone to step forward and create the article about this mineral. If you are so inclined and have questions about the format that such an article should have, go the The welcome topic at the top of the Best Minerals forum and read what has been posted there. Also take a look at some of the more mature articles that have already been written like Rhodochrosite, Adamite, Millerite etc. You will need also to pick out other images of Tungsten that will go into the article.



Tungsten
W Cubic
Bright grain of native Tungsten in back scattered electron image© PMK


Tungsten Native Element and Rare Species Collections


Known only as a few specimens from the earth and the moon. Synthetic material is often sold as Native Tungsten by fraud artists. I met Victor Ivanovich Stepanov in 1987 and asked him about W in wolframite from Transbaikalia and he replied with a good thick Russian accent "Product of American technology!" It sticks out like a sore thumb under the elelectron microprobe.To complicate matters it shows up in heavy mineral alluvial concentrates. These sample a widespread geology and often pick up anthropogenic material. These days one often finds metallic titanium in them from fallen space junk. So many of the earlier reported occurences of Native Tungsten were highly suspect. Certainly two honest occurences are from the moon where it was observed as a micron sized grain and in the Subarctic Urals where it was first found in an alluvial concentrate and later in a quartz vein occurence that drained into the concentrates.

Tungsten
Moon
Mare Crisium, Luna 24 landing site

Scanning electron microscope image of the fragment of lunar silicate glass particle from coarse fraction of regolith. The bright grain is a native tungsten aggregate overgrown with a carboniferous film covering the glass. Associated minerals located near this grain (within about 30 μm circle) are native molybdenum, copper, nickel and chromium. Depth of sampling is about 86 cm from Moon surface. The specimen is in the collection of Lunar regolith belonging to IGEM RAS and Andrei V. Mokhov took the photo.

Pavel Kartashov writes:

What about the Moon, impact events are the great refinery - they evaporate cubic kms of rock dividing elements of rock each from other in plasma. So some of them hadn't enough time to oxidize back.

Tungsten
Earth
Russia
Urals Region, Subarctic Urals, Bol'shaya Pol'ya River

Pavel Kartashov writes:

"On Bol'shaya Pol'ya river was found large cm size nugget of native wolfram. It was found in borehole of gold placier from ~30 m depth. This layer of gravels was deposited 50000-100000 years ago. May it be product of Hiperborean culture? Or may be Atlanteans had visited this region?

This native W contained <<1 micrometer grains of cubic Y2O3. It was observed in TEM preparates and was investigated on ancient (70th issued) KEVEX attachment. It didn't allow to obtain complete REE spectrum from the particles. And on KEVEX spectra other than Y peaks were invisible. BUT yesterday I analysed Alpine "gadolinite" and on its ED spectra also minor REE were invisible. But quantitative analysis on modern equipment show composition (Y1.58REE.30)1.88 where REE were Nd,Sm,Gd,Tb,Dy,Er,Yb. So may be this Y oxide isn't too pure. But it is too small for to be investigated by our microprobe. I had made some microprobe preparates from material of this nugget, but was unable to detect Y oxide inclusions in it because they are to small.

My the second find of native W in the region confirming natural source of W nugget into placier of B. Pol'ya river. I had identify it in quartz wein #60 of Puiva Mt. It is remarcable, that Puiva Mt is located in headstream of Bol'shaya Pol'ya river So apparently exactly this region supply native W gold placiers of the river. Very important is the fact, that on Puiva Mt. was apparently exist big nugget of native W. Unfortunately it was crushed up to 0.3 mm fraction with small semiindustrial probe of quartz of 2 ton weight. I observe fragments of this individual in heavy concentrayes from this probe. In whole pan of this concentrate (mainly apatite) was presented about 30-50 g of W particles as I am suppose. Unfortunately I am not Victor Ivanovich and recognize these grey metallic grains as some arsenide or sulphoarsenide. I was EXTREMELY foolish and selected for microprobe identification only 3 grains. How I was surprised, when all 3 turned out metallic W. Unfortunately all pan of this heavy concentrate was already thrown out, when I'd return to lab to take it... "



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Edited 5 time(s). Last edit at 07/26/2010 11:45AM by Rock Currier.
avatar Re: Tungsten
October 05, 2009 08:32AM
Good start. Now we have the framework to build on.

Rock Currier
Crystals not pistols.
avatar Re: Tungsten
October 05, 2009 09:24AM
ca    
Thanks Rock. I hope others will descibe any other real occurences, Also I hope that Stuart and Pavel might get together and get it accepted as a valid species. I wonder what they would name it???X(.
Re: Tungsten
July 16, 2010 01:32PM
I was and still am suspicious about natural native tungsten. The atmosphere of mineralogy labs (and mechanic shops) is heavily contaminated (with WIDIA hard metal and all kinds of metallic dust, Cu-Sn in particular). An effective genuineness test would be if any claim of W detected under SEM/EDS would at the same time guaranty the absence of Co (used as binding metal of compressed W-powder in WIDIA) and Cu-Sn-containing dust. I wonder why dealers don't raise that aspect.
Re: Tungsten
July 17, 2010 11:08AM
at    
This relates also to the problem of qusongite, supposedly "natural" WC. However, it was not found in situ (in a rock matrix) and the SEM photo in the original description clearly shows characteristically shaped, synthetic WC crystals, according to a specialist on W metallurgy I know personally.
Re: Tungsten
July 17, 2010 03:31PM
It happens that I used to do some work on natural carbides, and met with some disappointments when buying labelled "native W", which turned out to be plain wolframite. This is why I overreacted. I am keen of re-habilitation of natural refractory metals and their carbides (like khamrabaevite), but felt compelled to express a caveat. In my former message, I should have made it clearer that the most plausible contaminant is WC, considering that the carbon in WC (WIDIA) is extremely difficult to catch, and remains undetected if not chased around purposedly.

(BTW, a mineralogist/geochemist who worked on the East African Tungsten Belt cannot have a W-free day: So much problems still remaining !...)

Cheers! J.J.

Jedwab, J. and J. Boulègue: A vanadium-titanium carbide inclusion in graphite from hydrothermal ejecta at 13°N, East Pacific Rise. Canadian Mineralogist, 1989, 27: 617-623. (http://rruff.geo.arizona.edu/doclib/cm/vol27/CM27_617.pdf)

Jedwab, J. : Native ruthenium in tantalum carbide concentrates from the Ural Mountains, USSR. Mineralogy and Petrology, 1990, 43, 137-146.
avatar Re: Tungsten
July 20, 2010 11:00PM
ru    
Dear Jacques,
you can be absolutely sure, that native tungsten from Bol'shaya Pl'ya river is metallic W - malleable white-grey metal, not WC or wolframite. :) ;) Lunar material also is plastic native metal embedded into impact glasses of regolith in association with native Mo, Fe, Ni, Cu, Sn, Zn, Cr.
Kind regards,
Pavel
avatar Re: Tungsten
July 21, 2010 01:03AM
au    
You guys wont have to wait long to see it as a new mineral :)
avatar Re: Tungsten
October 26, 2010 12:18AM
ca    
Thanks Stuart. When can we get together?
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