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Is this "aluminum" possibly real?

Posted by Bob  
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Bob January 07, 2005 10:42PM
Hello, I just signed up last night so that I might ask a question in the chat area, but I can't seem to get into the chats.

I looked around for rules and couldn't find any, so I hope that I'm not posting anything wrong here.

I am watching an auction on eBay, and wonder if you experts could tell me if this is a legit mineral specimen or not. I've never seen anything like it, and can't find any reference to it in any of my books.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6502371838

The listing leads one to believe that this is a specimen of native aluminum.
Is that possible? Do you think this may be slag from a smelter or the like?

I would appreciate any thoughts you may have on this piece. It sure is an interesting looking item, but....


Also, just what does one have to do to enter the chat area?
Thank you for any replies. Hope that I didn't break any rules by posting an auction link.
Bob
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Alfredo January 08, 2005 12:11AM
Looks like the seller already has $255 coming to him for it.... Caveat emptor.
This is why many of us prefer to buy our minerals at shows, so we can pick the rocks up, look at all sides with a loupe, compare other specimens from the same locality, see whether the seller is grinning insanely, etc, etc....
The specimen in question has a shape remarkably similar to synthetic specimens, but who knows, maybe this is a case of life imitating art, but I won't be bidding against you, Bob!
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Jim Ferraiolo January 08, 2005 01:40AM
Looks synthetic to me. The only references I can find for Chinese localities for native aluminum are :

The native aluminum discovered in the Lianhuashan tungsten deposit, Guangdong.
He-Shuahgmei; Cao-Fenyuan; Liu-Yanzhong
Dizhi yu Kantan = Geology and Prospecting. 26; 9, Pages 32-34. 1990.

Abstract: Native aluminum was discovered in quartz dioritic porphyrite and altered quartz sandstone in the Lianhuashan tungsten mining district. It has an irregular grain shape, usually 0.02-0.04mm in size and white in colour, and occurs as an impregnation ore in gangue minerals.

Discovery of native aluminum in the oxidation zone in Getang, Anlong County, Guizhou Province.
Jiang-Xinshun; Li-Wenkang; Zhang-Shuxin; Meng-Fanyi
Bulletin of the Chinese Academy of Geological Sciences. 11; Pages 79-86. 1985.

Abstract: Native aluminum was discovered in the jarositized quartzitic rock of replacement origin at Getang, Anlong County, Guizhou Province. The bulk of the native aluminum occurs in cracks in and along boundaries of jarosite, and only a small amount is present in and along the grain boundaries of quartz. It is frequently associated with native copper and sulfur which have replaced jarosite. Electron-probe analysis shows that it contains 97.811% of aluminium, and electron diffraction and X-ray powder method indicate that a (sub o) is 4.0507Aa. So it is considered as native aluminum.

The size listed for the first occurrence above is probably the largest I've seen, and these are irregular grains, not crystal groups.
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Alfredo January 08, 2005 04:39AM
Thanks for these fascinating references, Jim. I've long been curious about native aluminum. My chemist friend John Attard says there is insufficient energy in any conceivable geochemical reaction to reduce aluminum from its oxide to the metal, so he doesn't believe in the existence of native aluminium. (I wonder whether Peter Haas will confirm that?) Nevertheless, native Al has been reported in a wide variety of geological environments: hydrocarbon-rich mud in Azerbaijan, serpentine in Italy, volcanic fumarole in Russia, and now your chinese references - two more completely distinct environments. I wonder what the mechanism of reduction was? (assuming it started out as an oxide or oxysalt, which might not be the case).
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Matt January 08, 2005 08:16AM
Hello

As a PhD chemist with 25 years experience I would argue that in spite of these reports aluminium will never, never, never, ever occur free in nature as the native metal. It is not only a case of reduction from its ores, but also in the electronegativity scale aluminum is the 6th most reactive metal known. Consequently left out in the open it will very rapidly react with oxygen, water or anyhting else for that matter, to become an aluminium compound and thus not the native metal. You may thin, oh I've had an aluminium cooking pot for years, but if you look carefully the surface is always dull and not metallic, the reason is that the surface is coated by a protective layer of aluminium oxide. Scrape that away and the bright aluminium beneath will tarnish again in a matter of hours. Anyway, thats my penny's worth.

Matt
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Maurice January 08, 2005 01:30PM
Hi Matt,

Well I'm afraid you are wrong here. Native aluminum DOES occur in nature. Nature provides many extreme environments. IThere are at least ten valid localities of native aluminium in Russia alone. The only one I have personally visited in the Karymsky volcano. In the 1996 Akademia Nauk volcano eruption at the foot of Karymsky volcano pumice was produced. Inside the pumice are microscopic inclusions of cordierite, glass and sulfides. native aluminium is one of the minerals found here.
Other types of localities include ultrabasic intrusions such as the Tsepochechnyi intrusion in Yakutia.

As for the thin layer of oxides on your pots and pans. That is true, but does not imply that there is no aluminum underneath! Same with the natural stuff it is shielded from the atmosphere by other minerals.

Nevertheless such large samples as the one on ebay looks very synthethic to me.

Cheers,
Maurice
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Jolyon January 08, 2005 03:27PM
That ebay auction is misidentified - it's probably manganese oxides of some kind, or goethite. It's certainly not Aluminium.

This seller seems to sell other wildly misidentified stuff, for example:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6501210405&ssPageName=MERC_VI_RSCC_Pr4_PcY_BIN_Stores

is shown as a 'stannite gem crystal cluster', with green translucent Stannite crystals! (for those who don't know, Stannite is a metallic mineral)

So I would treat their 'Aluminium' with great suspicion!
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Dave January 08, 2005 05:54PM
A friend send me a picture with very similar form. He works in a foundry and picks up pieces of slag and leaks from molds to use as display stands. His are smaller but same 'tree shape cluster'

I saw this offering a couple days back, having worked with metals all my life as a toolmaker. the rockhound is always curious. Native AL does exist, but I've never read about anything much bigger than sand grain size.

Any claims made on Ebay become suspect, and any materials coming out of China doubly so.
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Everett January 08, 2005 06:55PM
Bob,
As far as chat do you get a gray screen? If you do you must wait for the java to load. If you dont get a gray screen (XP) computers sometimes you have to go download sun java found here http://java.sun.com/

Hope this helps.
A group of us chats every day around 8 Michigan time......

E
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Ray January 08, 2005 07:11PM
I have been personally quite cautious about native aluminium, but I have been growing in my acceptance that the Russian material is not one of their fabulous fakes after all, and my seek out a specimen for my own native element collection some time soon. As for the reactivity, why not consider the improbability of Native Iron, but the Greenland material materials are real , so why not native aluminium.
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Maurice January 08, 2005 07:20PM
Ray,

I'm caution about any rare native element (Ti, Si, In, Ta etc) . Especially in the mineral market. The same goes for the expensive PGM minerals, where you get an analysed 0.1mm grain with five rare minerals and an SEM picture for $300. Too much money for something I can not check for myelf!

I do happen to have a Karymsky native Aluminium, but I got it personally from a Kamchatkan volcanologist while I was there. I saw the analyses and took their word for it. Then again it was a free gift. :-)

Cheers,
Maurice
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Alfredo January 08, 2005 09:58PM
Ray,
Nature can easily reduce Fe minerals to native iron with just heat and carbon, which is why native iron is not a rare mineral, but that isn't possible with aluminum.
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ian jones January 08, 2005 10:18PM
just a thought - but one based on quite a few years experience (not necessarily all with minerals!) and with lots of mistakes along the way - If something is too good to be true, it invariably isn't!

As Alfredo wisely points out - Caveat emptor.
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Bob January 09, 2005 12:07AM
I thank you all for your informative posts. I hadn't planned on bidding on this item, just wanted to understand it. The final bid was over $700.


Caveat emptor indeed!
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Don Webb January 12, 2005 08:11PM
I would be highly suspect of anything coming out of China and being offered on EBAY.
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Alfredo January 12, 2005 09:28PM
Don, I've seen misidentified rubbish offered from the USA, Germany, and other countries too. I don't think that the Chinese in general are more guilty than any other group, but they do have the advantage of being far away, so it's more difficult to get your fingers around the throats of the guilty ones!
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Chris Popham January 13, 2005 09:22AM
I seem to recall a post to one of the topics on the message boards in the last 6 months which put a figure of 10-15% of samples at trade shows being mis-identified.
That aside the aluminium is very interesting to look at natural or otherwise but I'm not sure it's $700 interesting.
Chris
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andy christy January 13, 2005 11:04PM
Things to bear in mind about the "reactivity" of aluminium:

1. Although it is true that the electrode potential of coating-free Al metal is very positive, and that the formation of corundum from Al and oxygen is very exothermic, it should be borne in mind that the partial pressure of oxygen in deep-sourced igneous materials starts VERY VERY low.

2. At high temperatures, Al is not only volatile itself, but also (under reducing conditions) forms a gaseous suboxide Al2O. Theformation of the latter is a counterindication for using alumina as a ceramic material under reducing conditions at high temperature, since the Al2O3 can gradually become weak and porous as Al2O evaporates out from it.

3. The high entropy of gaseous phases stabilises them relatively at high T, which therefore makes low oxidation states (0 and +1) of aluminium more favourable relative to Al3+ in corundum.

I suspect that vapour transport of Al and Al2O followed by reverse disproportionation of the latter on cooling is important in producing the metal at Tolbachik.

I agree completely that if any of this material was left on a mine dump for a few centuries, there would be little native Al remaining. However, the host samples for Al are all, as far as I know, recently obtained drillcore or fresh fumarole deposits.

Room-temperature thermodynamic data should be used with great caution in predicting the occurrence or not of mineral phases, which may have formed under very different equilibrium or disequilibrium conditions, and persist only through slow kinetics of re-equilibration. Just look at the carbon polymorphs:

graphite is the stablest form of pure C at ambient , and is common, as predicted.

diamond should not occur in the crust, but does, because it is possible to get it to the surface and cool it fast enough to prevent inversion to graphite.

lonsdaleite, chaoite (if real), and buckyballs do not have stability fields, are ALWAYS metastable, but nevertheless occur in shocked or otherwise disequilibrated material.

And all of these forms ought to burn to CO2 in a 20% oxygen atmosphere, but the kinetics is slow unless you help them!
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Rock Currier January 19, 2005 07:36AM
*Aluminum Rare species collections.
Al, A native metallic element.
Aluminum has now been found in several localities in Russia and elsewhere. It has been found in diatremes in Kazakhstan and a skarn deposit at Taror, Tajikistan and in epithermal veins at Nikitovka Mercury deposit, Ukraine. Also found in a lunar rock. Initially there were many in Russia and elsewhere who felt that native aluminum was reported in error. Even the late and highly venerated Michael Fleischer commented “This seems extremely improbable from thermodynamic considerations.” Translating this into the common vernacular it means “No fu----- way!” Dmitry Belakovsky of Moscow thought he had discovered native aluminum in some charoite samples he was working on. It turned out however that the aluminum was from the aluminum foil that the miners had used to wrap the explosives they were using when blasting the charoite out of the deposit. This and other reasons made it difficult for many researchers to believe that native aluminum had actually been discovered. Dimitry assures me however that he has seen some specimens of aluminum in matrix that are certainly authentic.
1 American Mineralogist, Vol. 65, p205, 1980.
Russia
Southern Ural Mountains, Orenburg Oblast, Kumak Deposit. Material was found in quartz veins. The best specimen was a 3 cm piece of gray white quartz with a thin sheet of native aluminum measuring about 5 mm across.1 The specimen is in the Fersman Museum in Moscow.
1 Dmitry Belakovsky, personal communication 2002.
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Rock Currier January 19, 2005 07:37AM
For what it is worth.

*Aluminum Rare species collections.
Al, A native metallic element.
Aluminum has now been found in several localities in Russia and elsewhere. It has been found in diatremes in Kazakhstan and a skarn deposit at Taror, Tajikistan and in epithermal veins at Nikitovka Mercury deposit, Ukraine. Also found in a lunar rock. Initially there were many in Russia and elsewhere who felt that native aluminum was reported in error. Even the late and highly venerated Michael Fleischer commented “This seems extremely improbable from thermodynamic considerations.” Translating this into the common vernacular it means “No fu----- way!” Dmitry Belakovsky of Moscow thought he had discovered native aluminum in some charoite samples he was working on. It turned out however that the aluminum was from the aluminum foil that the miners had used to wrap the explosives they were using when blasting the charoite out of the deposit. This and other reasons made it difficult for many researchers to believe that native aluminum had actually been discovered. Dimitry assures me however that he has seen some specimens of aluminum in matrix that are certainly authentic.
1 American Mineralogist, Vol. 65, p205, 1980.
Russia
Southern Ural Mountains, Orenburg Oblast, Kumak Deposit. Material was found in quartz veins. The best specimen was a 3 cm piece of gray white quartz with a thin sheet of native aluminum measuring about 5 mm across.1 The specimen is in the Fersman Museum in Moscow.
1 Dmitry Belakovsky, personal communication 2002.
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