# Adding more meteorites to my collection

• I
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## Main Question or Discussion Point

I'm addicted to space rocks.... I just can't help myself

These 3 came from a meteorite seller in Poland
http://www.polandmet.com/

And still awaiting for the postman to arrive with a Cuban meteorite via a seller in Arizona, USA.

2 of these latest samples are very nice slices nickel-Iron

The bolded names are the official names and usually indicate where they were found ...
near a town, a county, etc
NWA = North West Africa

NWA 6903 is from Morocco
Fall Date: unknown, Found: 2008
Nickel-Iron
Meteoritical Bulletin Database
https://www.lpi.usra.edu/meteor/metbull.php?code=53891

Mt Dooling is from Western Australia
Fall Date: unknown, Found: 1909
Nickel-Iron
Meteoritical Bulletin Database
https://www.lpi.usra.edu/meteor/metbull.php?code=16771

And the gem, of the 3 purchases, is a slice of moonrock that arrived on earth as a meteorite

NWA 11421 is from Morocco
Fall Date: unknown, Found: 2017
Achondrite, Lunar Feldspathic Breccia ( Achondrite = a stony meteorite that does not contain chondrules.
If you look at the sample below, you will see no circular material (chondrules) rather they are
rough irregular shapes typical of a breccia)
Meteoritical Bulletin Database
https://www.lpi.usra.edu/meteor/metbull.php?code=66054

cheers

Dave

Related Astronomy and Astrophysics News on Phys.org
How cool it is to touch something formed maybe light years away!? Makes me want to start collecting!

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How cool it is to touch something formed maybe light years away!? Makes me want to start collecting!
It really is ! Just holding something that has zoomed through space for countless zillions of years
is amazing.
Other than the Moon or Mars meteorites, most/all material is understood to have come from the Asteroid Belt and some comets.

You bring up a good point that I don't think I have really considered. Do we actually see stuff from outside our solar system ? And if there is, how would we identify it as such? I must ask the question of that to those that know more than me

Makes me want to start collecting!
Go for it !
Greg, there are sellers in the USA that have samples at very reasonable prices, a lot of stuff under US100 each.
For me buying in stuff from overseas is a killer because of the bad exchange rate.

You may not want a whole collection, maybe just spend more money on a single reasonable sized sample
as a show piece in your lounge ... great talking point with visitors

That last sample I bought a few weeks back that was in my other thread

was AU$400 ~ US$250 .... not a huge outlay for a single sample if you were to do that
and hey, they never drop in price ! so are a great investment

Dave

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And if there is, how would we identify it as such? I must ask the question of that to those that know more than me
Age? Anything substantially older than 4-5 Ga, say?

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Age? Anything substantially older than 4-5 Ga, say?
Yeah, possibly, would have to pre-date rocky material from the solar system formation

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NWA6903 looks like charred fiberboard, with its crystal growth and blackened outer shell.
Size of the crystal means it must have had a slow cooling at some point in its history.

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NWA6903 looks like charred fiberboard
Yeah, it does when thought about

Size of the crystal means it must have had a slow cooling at some point in its history.
Probably a fair assumption. Nickel iron meteorites are deemed to have come from the cores of
asteroids that have broken up as a result of collisions

That pattern you see is called the Widmanstätten pattern. It's a distinguishing feature of
Nickel-Iron meteorites

from wiki ....
Widmanstätten patterns, also known as Thomson structures, are figures of long nickel–iron crystals, found in the octahedrite iron meteorites and some Pallasites. They consist of a fine interleaving of kamacite and taenite bands or ribbons called lamellae. Commonly, in gaps between the lamellae, a fine-grained mixture of kamacite and taenite called plessite can be found. Widmanstätten patterns describe features in modern steels, titanium and zirconium alloys.
As hinted above, can be found in manufactured steels etc, it pretty much only occurs naturally in meteorites
The meteorite slice, like the one above, is cut, acid etched and polished to bring out the pattern

Dave

256bits
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With steel one needs a magnification to see the patterns - cooling rate fairly quick.

For the meteorites, millions of years. give or take, for the patterns to be visible to the naked eye, as there has to be diffusion for grain/crystal growth, and the longer it takes the material to solidify, the larger the crystals, leaving a lower surface energy at the boundaries. There could be, as a guess, some diffusion for the solid form also, though I don't know what that would be.

Knowing the rate of diffusion one can calculate the growth and the cooling rate., and then the size of the original larger chunk, that eventually broke up by collision ( or... ), and ones gets a meteorite that you now possess.

Not sure the claim "might have formed light years away" can be readily assessed as it is statistical and both spatial and temporal in nature as stars in our galaxy move around the galaxy. As the age of matter is typically determined based off when the material was last "reset" chemically/isotopically and any differentiated body will inheritly get its isotopic signature reset I don't think any of these could be classified as anything but solar. Were the isotopic ratios to have been found to be extra solar that would have made big new a while back.