Australites - have any/many members come across these whilst detecting?

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Australites - have any/many members come across these whilst detecting?

Post  Peta on Fri May 18, 2018 1:50 pm

A Tektite is a rare natural glass button or rod, formed when an asteroid strikes the Earth.

Tektites can be found at five widely separated locations on the Earth.

In Australia they are call Australites.

Not everything about how the glass forms is fully understood adding to the charm and mystery of this rare material.

The rocks which are melted and vaporized in the impact travel out to near space where the material cools to glass.

As it is falling back to Earth the globs are still plastic.

They are shaped by the atmosphere and by their spin, into aerodynamic forms.

Sphere, rods, dumbbells, patties, teardrops are among some of the shapes the glass receives.

These flanged Australites are highly prized and rare.

Often the flange will be thin and transparent.

On the surface that was facing down during flight and melted are often seen an intricate pattern of circular ridges.

These ring waves produced by the air currents on the liquid surface can be both interesting and beautiful.

We found a couple of these during our travels.

They can be sold and on average return $20 to $60 each, but this varies greatly.

Have any other members found any whilst fossicking or have you simply walked over the top of them kicking them out of the way.  Very Happy

I believe they can return to earth many miles from the original impact zone.

By the way, they can only be found visually, your detector will not pick it up, naturally.

Peter.




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Re: Australites - have any/many members come across these whilst detecting?

Post  davsgold on Fri May 18, 2018 2:06 pm

Yep we have found heaps of them probably over 100 or so.  Here is a few of them

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Re: Australites - have any/many members come across these whilst detecting?

Post  Peta on Fri May 18, 2018 2:12 pm


Davsgold which State did you find most? We found ours in WA.

Did you find any close to the impact (crater) zone or were they, as is usually expected, miles from any identifiable spot?

Peter.


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Re: Australites - have any/many members come across these whilst detecting?

Post  davsgold on Fri May 18, 2018 11:14 pm

All found in WA while gold detecting. No impact crators as these would be Metorites, some say the impact site is in Asia for all these Australian Tektites (Australites), you can google the tektite fields in Australia and the possible impact site.

Tektites are lighter in weigh than the ironstone that usually surround them and they are mostly sitting on top of the ground.

cheers dave
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Re: Australites - have any/many members come across these whilst detecting?

Post  nero_design on Sat May 19, 2018 3:21 am

Davsgold, those specimens you've collected are incredibly awesome. I was writing about them in a book I was working on a few years ago and I'm afraid that I put it on hold and haven't quite finished it.  But I dug out some images that I have posted here a long time ago that might be of interest to those collecting Tektites.  I have some image to share on the subject along with some information that collectors might find useful.  I hope you don't mind me posting it here below...

Peter, I collect meteorites and very occasionally find them.  Tektites are certainly part of that collection and I've found some smaller ones when out fossicking.  The glassy nature of the stone plus the bubbles in the matrix make it clear what they are although irregular chunks of grey glassy material of an opaque nature are often slag from local miner smelting operations... a bit like the coke they scrape off the blast furnaces.  I have heard China uses Coke (smelting fuel) to form fake Tektites but I can't confirm it yet.  They definitely produce fakes Tektites from other materials (see below).  The Australites that have an INTACT saturnian ring around the central sphere are incredibly rare because they generally shattered when they hit the ground.  They got this shape by spinning as they cooled.  I once saw a 2cm specimen for sale with an intact rim for $24,000 on Ebay but it didn't sell.  They relisted it several times before withdrawing it from sale.  Seller was in Australia and they had two.  The other one had a serious chip missing from one side of the rim.

* Tektites (from the Greek word "Tektos" meaning "Molten") are believed to have resulted from extremely large impacts from meteorites or asteroids.  Another existing theory is that Tektites exhibit evidence suggesting that some (not all) may be composed of volcanic ejecta from the moon.


Indochinite (Indonesian Tektite) sourced online from Thailand for about $30.  It's about the size of a clenched fist.

People have been collecting tektites for thousands of years.  The North Americans considered them a sacred stone and shaman would often carry them for healing rituals.  2000 years ago the Chinese considered tektites to be the "Inkstones of the Thundergod".  Australian Aborigines called them "Mahon" (Magic) and believed that it was good luck to find one.  Today, fossickers occasionally come across them and they tend to have a dark, grey, black or greenish tone with occasional yellow highlights if held to the light.


An Australian Tektite up close.

Unlike meteorites, Tektites are not particularly valuable because they are so abundant.   Most specimens, even larger ones, sell for between $3 and $ 40.  The Sydney Gem Show last week (2018) had boxes of them for sale for $10 each.  Smaller Australite Tektites of the Button type are much rarer and are sought by collectors, sometimes selling for thousands of dollars.  


Libyan Desert Glass - is quite collectible and can be found in large specimens. I bought this large, intact piece at auction for $50 but it's valued at around $7K


An Arrowhead that I acquired from a European Collection that is 30,000 years old - knapped from Desert Glass at an African site.  Particles of the ejecta can be seen under magnification.


Moldavite - an intact quality specimen and a cut gem that was produced from a similar sample.

Other related types of tektites include a green molten rock-glass from Europe such as "Moldavite" and the clear yellow-white "Libyan Glass" made from fused desert glass.  Moldavite (from Moldauthein in the Czech Republic) is considered to be an abundant type of 'gemstone' and will often attract a much higher price than the common black tektites.  The impact that produced them occurred around 15 million years ago and the deposit is concentrated in Moldavia... and they call this strewnfield a "Splashfield" because of the shape and "splatter" shapes of the Tektites it produced. Most examples are under 1cm in size and have a radiating textured surface Isotopic analysis demonstrates their composition to be similar to Tektites from the Australasian region and the Ivory Coast Strewnfield.  It is usually much smaller than other types of Tektite and often contains bubbles like other Tektites.  

Egyptian King Tutankhamen's pectoral necklace jewels included a scarab beetle centerpiece that was recently identified by Italian mineralogists as being composed of Desert Glass of the same origins as the Libyan Desert Glass... which has a melting temperature of 2,800F in order to have melted the sand.  It is highly prized by collectors and sells per carat and is treated as a gemstone, just like Moldavite.


How the impact might have looked from space, considering the distance the ejecta traveled and the amount of debris thrown up.


An accurate map that I've produced showing where Tektite samples from the Australasian Strewnfield can be found.  They appear to be more plentiful in the Northern Territory and Western Australia.

The most accepted theory for Tektite formation is that a massive meteorite impact with the Earth throws up molten material hundreds of kilometers into space where it rains back down on the surface of the planet.  The ejecta cooled and solidified as it rose up into the freezing temperature of space and formed a black or black-green glass as it returned to Earth.  The Australasian Strewnfield, European Strewnfield, North American Strewnfield and Ivory Coast Strewnfield make up the four known tektite sources on Earth.  The Australasian Tektite Strewnfield is the largest and geologically youngest (at an estimated 800,000 years old) and the impact crater may have been close to 120 kilometers in diameter.  A shallow lake in Cambodia called Tonic Sap might be the original impact site.  The dispersal of Tektites from this impact may cover up to 30% of the surface of the planet.  Tektites are not meteorites and do not respond to magnets or metal detectors. Tasmanian impact glass is quite rare, small and fragmented... but the color is uniquely different... perhaps as a result of its distance from the impact site.  

For the collectors here, be aware that the Chinese have mastered methods of producing fake Tektites, Moldavite and Libyan Desert Glass.  Many of the fake Moldavite specimens are simply crudely molded from an original specimen but these mass produced fakes sell on Ebay for big dollars.  The Libyan Desert Glass is also subject for forgery and in both cases are produced by melting local broken bottles to produce a crude "specimen".  Most fakes are easily identified by some are quite good.  Good enough to fool the casual Ebay browser in some instances.  In the end, the best source of these things is still Ebay.  Try to locate a respectable seller and you should be fine.


Fake Moldavite being sold on Ebay.  This one was selling for USD $120.99 (+$6 shipping) when I saw it. Note the soft surface details and obvious lack of fine structures.  it's made from melted crushed glass bottles. This seller was from Lianyungang Juangsu in China.


Shocked Quartz from Gosses Bluff, NT

Last on the related subject is Shocked Quartz.  Usually this is determined under a microscope but occasionally we get a specimen that is large enough to demonstrate the source of its deformation.  This specimen shows directional melting where an impacting meteorite or asteroid literally melted the surface of the nearby quartz on impact with the Earth.  If you squint a little when you look at this sample, you can see the "flow lines" where the heat from the impact blast (which was presumably similar to a powerful nuclear detonation) melted the quartz like a blowtorch on toffee.  This is quite common to find near several of the larger impact sites like the one at Gosses Bluff in the Northern Territory... but most people don't notice it or ignore it altogether.  I have no idea if it's valuable but I have only once seen a palm-sized specimen for sale and I think it was a few hundred dollars or less.
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Re: Australites - have any/many members come across these whilst detecting?

Post  nero_design on Sat May 19, 2018 3:48 am

If anyone is wondering how our own molten Eart-rock forms Tektites upon impact with an Asteroid or Comet... here's some images from the Kilauea lava eruption that I photographed in Hawaii a few years ago and you can see how the black molten rock turned to dark glassy obsidian when it cooled... complete with air bubbles.  My wife got 2nd degree burns because the UV light from the sunlight reflected off all the lava just like a mirror.  The freshly cooled lava had a rainbow sheen t it.  Anyone who tripped or fell on it was literally shredded because every bubble had a razor sharp edge to it.  A rather stunning American girl in our group (in a bikini with thongs on her feet) returned to us after a couple of hours with blood pouring down both her legs from where she'd tripped a few times and ended up coming in contact with the dry obsidian lava flow.  When you touched it, the sharp surfaces sliced off your fingertips as easily as a fresh razor blade.  Running is definitely not recommended.


Imagine millions of metric tonnes of this material being punched out of the earth and cooling in space on the way down.  I guess that these lava deposits are simply terrestrial tektite raw material.


Closeup of the Lava... showing the black obsidian and embedded gas bubbles... just like the material that produced the Tektites.


My wife trying to cross the lava flow... which we walked on for about 2 kilometers before my sneakers melted under my feet from the fresh flowing lava underneath the crust we were walking on.
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Re: Australites - have any/many members come across these whilst detecting?

Post  au-fever on Sat May 19, 2018 7:54 am

I have quite a few tectites that I have found over the years, the most recent ones on the edge of a salt lake roughly 60klms north east of Paynes Find, they are easy to spot on the surface of the salt so that is the best place to search for them, it would be very hard to distinguish them as they are black in colour and blend in very well amongst the iron stone rocks, these are glassy flat ones but have no halo ring and are quite warn, some of the others are better and one is around 30mm wide.

cheers

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Re: Australites - have any/many members come across these whilst detecting?

Post  davsgold on Sat May 19, 2018 8:54 am

nero_design wrote:Davsgold, those specimens you've collected are incredibly awesome. I was writing about them in a book I was working on a few years ago and I'm afraid that I put it on hold and haven't quite finished it.  But I dug out some images that I have posted here a long time ago that might be of interest to those collecting Tektites.  I have some image to share on the subject along with some information that collectors might find useful.  I hope you don't mind me posting it here below...


G'day nero

I always enjoy reading your posts and viewing your photos, and I don't mind at all your posting here about the Tektites etc.

cheers dave
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Re: Australites - have any/many members come across these whilst detecting?

Post  Peta on Sat May 19, 2018 10:04 am

Thank you Nero, that's a fabulous post, most informative.

When coming across a single Ausatralite would it be common to find more in the same area or do they disperse further afield and not necessarily land close together?

So basically, if you find one is it possible to find more nearby?

Peter.


Last edited by Peta on Sat May 19, 2018 3:21 pm; edited 1 time in total

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Re: Australites - have any/many members come across these whilst detecting?

Post  nero_design on Sat May 19, 2018 2:38 pm

Peta wrote:

When coming across a single Ausatralite would it be common to find more in the same area or do they disperse further afield and not necessarily land close together?

So basically, if you find one is it possible to find more nearby?
.

I guess so.  But they cover most of Australia so I don't know how likely it will be.  I believe that the best place to find them would be in depressions where stones gather and in creek beds (dry or wet). Due to their shape and size and specific gravity, they're likely to end up getting washed into deposits with others. Places where humans have built cities will be nearly impossible to locate any.  But in the dry regions where few people have walked there ought to be plenty scattered about.  I'm not sure how abundant they are here.  They are certainly extremely common in the Asian region (Thailand and Cambodia etc) and I've seen pictures of trucks over there being filled with thousands of larger tektites.  The Tektites found in the Salt Lakes of Western Australia can be very well preserved from the weathering conditions they would have endured out of the water. The ones found in the oceans are considered to be the best preserved due to the alkaline in the sea water.  Those found on land tend to be deeply etched on the surface.


ABOVE:   Distribution of tektites (+) and microtektites () from the Australasian strewn field.


NOTE: "You can own and export tektites (which are not considered as meteorites) freely in Australia, except for in the Northern Territory. In the NT the state owns all tektites found after 12 July 2000."

This law is under the 'Protection of Movable Cultural Heritage Regulations 1987, Statutory Rules 1987 No. 149 (as amended), made under the Protection of 'PROTECTION OF MOVABLE CULTURAL HERITAGE ACT 1986'.

Northern Territory:
Summary of the law regarding tektites: In the Northern Territory of Australia Meteorites Act 1988 the term meteorite includes tektites. Meteorites/tektites found in the Northern Territory after 12 July 2000 belong to the state (Museums and Art Galleries Board of the Northern Territory). Tektites found outside of the Northern Territory or before the 12 July 2000 do not belong to the state, but the onus is on the owner to prove this is the case – i.e. if you can’t prove this then your tektites may be taken by the state. The state will compensate the property owner the value of the specimen, which is recoverable in court.

Western Australia:
Summary of the law regarding tektites: In the of Movable Cultural Heritage Regulations 1987, Statutory Rules 1987 No. 149 as amended, Protection made under the Protection of Movable Cultural Heritage Act 1986, meteorites are protected and tektites are not mentioned.

South Australia
Summary of the law regarding tektites: In the South Australian Museum Act 1976 ‘meteorite means any naturally occurring object that has fallen to earth from beyond the atmosphere, but does not include a tektite’. Thus, tektites are not covered by the South Australian Museum Act 1976.
In the of Movable Cultural Heritage Regulations 1987, Statutory Rules 1987 No. 149 as amended, Protection made under the Protection of Movable Cultural Heritage Act 1986, meteorites are protected and tektites are not mentioned.

Queensland, Victoria and Tasmania
Summary of the law regarding tektites: [i]In the of Movable Cultural Heritage Regulations 1987, Statutory Rules 1987 No. 149 as amended, Protection made under the Protection of Movable Cultural Heritage Act 1986, meteorites are protected and tektites are not mentioned.

New South Wales
Summary of the law regarding tektites: [i]In the of Movable Cultural Heritage Regulations 1987, Statutory Rules 1987 No. 149 as amended, Protection made under the Protection of Movable Cultural Heritage Act 1986, meteorites are protected and tektites are not mentioned.  Movable.Heritage@arts.gov.au, Program Officer, Cultural Property and Gifts, Office for the Arts, Department of the Prime Minister and Cabinet, 33 Allara Street, Canberra stated that ‘Tektites are not considered meteorites under the Protection of Movable Cultural Heritage Act 1986, and therefore do not require permits from us for export’.  WA Museum stated ‘Because they are not meteorites, tektites are not covererd [sic] by meteorite legistion [sic] in WA. They were also removed from the control lists of the Federal Protection of Movable Cultural Heritage Act (1986) some years ago. In effect there is no impediment to the export of tektites from Australia’. (except for the Northern Territory due to the Northern Territory of Australia Meteorites Act 1988). Also it is noteworthy that any tektite valued in excess of AUD 10,000 would be a Class B object and require an export permit (although at the time of writing not even the rarest tektite would be valued greater than this). It is also noteworthy that any tektite worked, associated or used by people would also potentially be a Class B object and require an export permit
.
[/i][/i]

Source: http://www.tektites.co.uk/index.html
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Re: Australites - have any/many members come across these whilst detecting?

Post  nero_design on Sat May 19, 2018 2:51 pm



https://www.meteorite-times.com/norms-tektites/aussie-flanged-button/


You might find this short article interesting. (see link above)

The buyer obtained some of the best looking Aussie "button" Tektites he had ever seen... from a seller that was unfamiliar with them.  It dawned on him that they were "too good to be true" so he tested one with a knife and discovered it was "plastic" (probably heavy resin).  It turned out that the deceased person was a curator for the Smithsonian Museum in America and had retained some of the molded replicas used for display.  At least SOME of the tektites in the lot were actually real.  The one in these pictures was (apparently) not.

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Re: Australites - have any/many members come across these whilst detecting?

Post  Peta on Sat May 19, 2018 3:27 pm


This question may be too basic or to diverse to answer simply;

Is there an easy way of identifying a meteorite in the field?

Peter.


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Re: Australites - have any/many members come across these whilst detecting?

Post  adrian ss on Sat May 19, 2018 7:52 pm

NO! Unless you have had a lot of hands on experience, and even then you can get it wrong.
  I had a large rock that I thought may have been an iron meteorite and I had it checked by an expert who said yes it might be. So I had a chemical analysis carried out on said rock and it is a large piece of haematite. Approx 2kg wt


http://meteorite-identification.com/streak.html
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Re: Australites - have any/many members come across these whilst detecting?

Post  geof_junk on Sat May 19, 2018 8:24 pm

Some large tektites surrounding a 4 ounce nugget.




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Re: Australites - have any/many members come across these whilst detecting?

Post  Peta on Sat May 19, 2018 8:43 pm


Now that's a picture of a happy trip.

Peter.

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Re: Australites - have any/many members come across these whilst detecting?

Post  adrian ss on Sun May 20, 2018 9:00 am

Who would pick this as a meteorite?

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Re: Australites - have any/many members come across these whilst detecting?

Post  Minermike on Sun May 20, 2018 1:16 pm

I did have a pamphlet on Tektites that was put out by the W.A. Gov./mines dept / museum ? No longer have but it was put out by one of those .
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Re: Australites - have any/many members come across these whilst detecting?

Post  geof_junk on Sun May 20, 2018 3:02 pm

LINK--->WA tektites

Link above for Minermike



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