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
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... "
Edited 4 time(s). Last edit at 10/04/2009 08:41AM by Rob Woodside.
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