Undergrad Adding more meteorites to my collection

[Vanadium 50]

So how come your California source has Moon display boxes and Mars display boxes but no 4 Vesta display boxes? Vesta is not feeling the love?

 

[davenn]

So how come your California source has Moon display boxes and Mars display boxes but no 4 Vesta display boxes? Vesta is not feeling the love?

Didn't notice that till you pointed it out.
Poor Vesta and the other asteroids I guess that the material from Vesta and the other asteroids is just so much more common
compared to the Moon or Mars that they didn't deem it worthy.

 

[Vanadium 50]

But Vesta is special. It's not just any asteroid - it's one where we can look at a meteorite and say "that asteroid". Further, we can say "that impact on that asteroid" which we can't say for the moon or Mars.

As I was writing this, it dawned on me that HED meteorites tell us a lot about the sources of other meteorites. Vesta is 9% of the asteroid belt's mass, but only 5% of the meteorites. Furthermore, a good portion of what used to be its southern hemisphere was blasted into space. That should make the fraction go up, not down. So therefore most meteorites aren't coming (directly) from the belt, but rather are likely in closer orbits.

Now I am puzzled not by why there are so few, but why there are so many.

 

[davenn]

another couple of parcels arrived today

8 meteorite samples inc. one really special one. The lower 3 pic's in the centre give a hint ...

That hint aiming at the top left case. 4 fragments of meteorite and 4 pieces of shattered glass from windows damaged by the shockwave
when the 2013 Chelyabinsk ( Russia) meteor exploded over the town.
My friend in Arizona got hold of his mate in Chelyabinsk and had his freight to the USA a number of full window frames with the broken
glass so that he could make up these presentations
Other meteorites there are from Kenya, Northwest Africa ( mainly Morocco) and Algeria
The mentioned prices are US$, just to give some indications of costs for anyone wanting to have their own bit of outer space

This last sample is from Pakistan. A relatively fresh fall from earlier this year
The guy who got this out of Pakistan lost over 5kg of rock when it was confiscated by the govt

cheers
Dave

 

[Vanadium 50]

You're not going to be happy until you've reassembled an entire asteroid, are you?

 

[davenn]

You're not going to be happy until you've reassembled an entire asteroid, are you?

Haha Yeah, I gave up on putting a large amateur radio antenna tower up in the back yard. Too much govt (council) red tape
Don't see anything in their rules regarding the assembly of a 20m diameter asteroid

 

[Ibix]

"Asteroid, officer? No, this is just a rock."

 

[Vanadium 50]

Don't see anything in their rules regarding the assembly of a 20m diameter asteroid

Don't see any rules against putting a tower up on an asteroid. "Officer, these laws apply to Earth. This is 123456 Watchamacallit".

 

[davenn]

lots more goodies arrived in the post today ...

Top row, left to right ...

Kheneg Ljouad 0.8g; NWAxxx Pallasite 3.88g; 2 x Vaca Muerta 1.8g, 5.57g; Benenitra 5.3g; Buzzard Coulee 13.6g; D'Orbigny 0.219g

Middle row, left to right ...

Chergach 2.195g total; NWA12949 (Meso.) 3.07g; NWA4482 Pallasite 9.4g; 2 x NWA xxx OC; Muonionalusta pendant

Bottom row, left to right ...

5 x NWA xxx OC's

( NWA = Northwest Africa; OC = Ordinary Chondrite)

Those ones with the NWA Chondrite label are ones that have not been lab. classified
They usually get labelled as NWA xxx cheers
Dave

 

[davenn]

Well after being "lost" for 1.5 months somewhere in Sydney, by Australia Post and them denying that they had even scanned it
( even though their own tracking site said otherwise) I am so elated that out of the blue on Fri 31 July that it finally turned up

I welcome the arrival of my Gatuto piece, all 11.56g of it.

I really thought I was never going to see this one. just the day before it arrived,
I had asked the seller if he had any other pieces left for sale

Dave

 

[Vanadium 50]

You haven't posted a new meteorite in 3 weeks...are you OK?

What is a UNWA compared to a regular NWA and why are they 10x cheaper?

 

[davenn]

You haven't posted a new meteorite in 3 weeks...are you OK?

Hi ya,

Yes, still kicking. I have had 2 new postal arrivals and there are 3 more parcels on the way.
Hopefully one of those 3 I will see this coming week

The 2 that arrived one was from Brett, a seller in PA state of the USA

Top left was a gift he included 3 fossil teeth left to right

L -- Hemipristis is a genus of weasel sharks, family Hemigaleidae. It contains one extant species, the snaggletooth shark (H. elongata) and several extinct species. Hemipristis has two distinct types of teeth in each section of its jaw.

M -- Tiger Shark tooth -- The tiger shark is a species of requiem shark and the only extant member of the genus Galeocerdo.
It is a large macropredator, capable of attaining a length over 5 m.

R -- Stingray tooth - I don't know which species

----------

Top right is a new meteorite find ( but an old fall) the Erg Chech 002 from the desert area of SW Algeria.
One of the things that indicate an old fall is the total lack of fusion crust on any of the material found. It has long ago been eroded off. This meteorite was only classified ~ 4 weeks ago as an Achondrite-ungrouped. The Meteoritical Bulletin entry ...
https://www.lpi.usra.edu/meteor/metbull.php?sea=Erg+Chech+002&sfor=names&ants=&nwas=&falls=&valids=&stype=contains&lrec=50&map=ge&browse=&country=All&srt=name&categ=All&mblist=All&rect=&phot=&strewn=&snew=0&pnt=Normal table&code=72475

This an exciting new find as the meteorite is so very different to any other one because of its visual appearance colour and mineral content.
Many seasoned collectors have said " had they seen this rock without knowing that it was a meteorite, they would have said it wasn't one"

It contains distinguishing long green - yellow crystals of diopside ( a pyroxene)

------------

The lower meteorite is The Tassedet 004, an H5 melt breccia
explanation ...
Ordinary chondrite: A major class of chondrites, distinguished by sub-solar Mg/Si and refractory/Si ratios, oxygen isotope compositions that plot above the terrestrial fractionation line, and a large volume percentage of chondrules, with only 10-15 vol% fine-grained matrix.

H group: The high-iron (H) chemical group of ordinary chondrites, distinguished by their high siderophile element content, relatively small chondrules (~0.3 mm), and oxygen isotope compositions that are closer to the terrestrial fractionation line than those of other ordinary chondrites.

Type 5: Designates chondrites that have been metamorphosed under conditions sufficient to homogenize olivine and pyroxene,
convert all low-Ca pyroxene to orthopyroxene, cause the growth of various secondary minerals, and blur chondrule outlines.

Melt breccias come from all 3 known sources of meteorites, Lunar, Martian and the asteroids and are caused my impacts... asteroid - asteroid and asteroid to Moon or Mars

What is a UNWA compared to a regular NWA and why are they 10x cheaper?

Unclassified meteorites from NWA and other places are cheaper because they are unclassified.
The obvious features can be stated, eg. it's a chondrite, anchondrite or a melt breccia and estimates can be made to its metal content classification H = high iron, L = low iron etc. But unless a sample
was actually taken to a lab for chemical analysis, the fine details cannot be confirmed.
cheers
Dave

 

[davenn]

A new meteorite fall in NE Brazil on the 19th Aug 2020
A few of my fellow collectors from the USA rushed down to the area to hopefully collect some samples.
And were successful

The initial largest stone that fell was a 2.8kg one that went through the roof of a bar in the town of Santa Filomena

Entry Date/Time:	08/19/2020 13:18:17.16 UTC
Location:	Santa Filomena, Pernambuco, Brazil
Reference Coordinates:	8.173°S 40.544°W
Reference Altitude:	20.9 km above sea level
Energy / Mass Estimate:	> 0.01kt / >300kg
Reference Speed:	18.0 km/s
Bearing:	264.9° W
Slope:	47.3° from vertical
TKW:	>42kg recovered
Classification:	Chondrite, possibly L-type

about a week after the 2,8kg stone recovery, 38.2 kg stone was fount out of town.

I have purchased a 4.6 gram fragment of this meteorite ... will post a pic. of it when I canDave

 

[Ibix]

The initial largest stone that fell was a 2.8kg one that went through the roof of a bar in the town of Santa Filomena

I take it that selling the meteor has paid to replace the roof tiles and any spilled beer?

 

[berkeman]

Top left was a gift he included 3 fossil teeth left to right

Wait, what? Are those from Mars? Rhut-rho...

 

[Vanadium 50]

Dis you get a piece of the big one or the little one? Or both.

Here's another dumb question - why are there no meteorites from earth? i.e. an Earth rock with a fusion crust.

 

[davenn]

I take it that selling the meteor has paid to replace the roof tiles and any spilled beer?

Well initially, the govt was going to take ( no payment) the 2.8kg stone and put it into the national museum.
My understanding is, that now the 38+kg one has been found, it's going to the museum and the 2.8kg one
is getting sold by the owner. Not sure if my friend Michael Farmer, from AZ, USA, secured its purchase or not.
I know some of the broken roof tiles have been sold to him and one other.
Having man made materials that were damaged by a meteorite hit is a big bucks deal !

Dis you get a piece of the big one or the little one? Or both.

My piece is from a different smaller stone that has been broken up

Here's another dumb question - why are there no meteorites from earth? i.e. an Earth rock with a fusion crust.

Ahhhh let me dig for a reference, am sure one was possibly found on the Moon.

here we go ...
https://eos.org/articles/apollo-may-have-found-an-earth-meteorite-on-the-moon

But of course, it won't have a fusion crust as the moon has no significant atmosphere

Now there are Earth rocks that have been melted and blasted into the high Earth atmosphere
or just out of it and have come back down to Earth. These produce tektites.Dave

 

[Vanadium 50]

I'm thinking of something a little more classic-meteorite than a tektite, which I understand are located near the impact crater: debris that goes up and comes down again. I'm imagining something that goes up, stays up, and comes down later - probably many years later - somewhere else.

My thinking went like this. Of order 10^-3 of meteorites come from Mars. Which is easier? Mars-to-Earth or Earth-to-Earth? Probably Earth-to-Earth. So shouldn't there be a few hundred? They should be pretty easy to spot: a chunk of limestone with a fusion crust would do it. For a bonus, it could have a fossil in it. In fact, they would be so easy to spot I'd worry about forgery.

And, as you say, there is evidence of a very ancient Earth meteorite on the moon.

So where are they?

 

[pinball1970]

I am just checking you saw this alert

https://www.sciencealert.com/man-ke...ing-it-s-gold-it-turned-out-to-be-a-meteorite

@davenn

 

[davenn]

I am just checking you saw this alert

https://www.sciencealert.com/man-ke...ing-it-s-gold-it-turned-out-to-be-a-meteorite

@davenn

outstanding, thankyou for that !

 

[davenn]

I'm thinking of something a little more classic-meteorite than a tektite, which I understand are located near the impact crater: debris that goes up and comes down again.

WOW ... I'm only a year and a bit late in responding, must be a record for me, sorry mate
I have been pretty inactive on PF of late ... for quite some months actually ... all sorts of crap going on...

Actually tektites can fall far from the source ... Australites, Australian tektites, obviously haha and found all over
Australia have their source in SE Asia... same location as the other Indochinites in this group Cambodia/Laos area.
I do have a better map and location info somewhere for this.

The Indochinite tektite group has the largest strewnfield of all the ones known.

I'm imagining something that goes up, stays up, and comes down later - probably many years later - somewhere else.

That would have to be injected into some sort of low Earth orbit, maybe ?
I haven't so far not heard of anything like that, not saying it's impossible, just never heard of it having been spoken of.

They should be pretty easy to spot: a chunk of limestone with a fusion crust would do it. For a bonus, it could have a fossil in it.

The problem most likely is, that the rock wouldn't be lumps of limestone or whatever Earth rock. The force of the impact
would at best form a significant breccia ( melt breccia), like we see with stuff from the Moon, Mars and some of the asteroid
meteorites. At worse, it would be completely melted, aka the tektites we see, with much the same consistency, physically and
chemically as obsidian ( volcanic glass).
cheers
Dave

 

[davenn]

hey everyone,

well my meteorite collecting has slowed down over recent months after a major splurge over 2020 and a lot of 2021.
It took my collection from around 30 samples prior to Jan 2020 to over 260 as of today.
Till a few days ago my largest meteorite was a 1.5kg specimen from Morocco, Northwest Africa ...

This last photo shows the leading surface as it came into the atmosphere

This 1.5kg stone has now my well superseded by my latest acquition ... a 5.25kg meteorite, also from Morocco

Like the 1.5kg met., this one is also an OC - Ordinary Chondrite.
I don't plan on cutting it to get a sample classified. It's just too nice for that !

cheers
Dave

 

[Vanadium 50]

after a major splurge over 2020

Would that be a meteor shower?

 

[davenn]

Would that be a meteor shower?

YES! Definitely LOL

 

[hutchphd]

This 1.5kg stone has now my well superseded by my latest acquition ... a 5.25kg meteorite, also from Morocco

You know, at the point you need a backhoe to manage the collection, you might want to reconsider...

 

[Hornbein]

Agreed, I have never heard anyone claim that they have one that is from outside of the solar system

I have heard this. There is also recently a meteor that was tracked at such a speed it must have been interstellar.

 

[ISamson]

Hey @davenn, you really have an intriguing hobby!

As many others have said earlier, I imagine it would be really amazing to hold something from space right in your hands!

But I am wondering, how do you differentiate, how do you know that the rock you find or buy is really a meteorite? I have tried Googling this, but it's really quite generic. For instance, when global sellers ship them to you, how do you know that you are not being tricked? ;)

And if I were to go on a walk in the Outback and find an interesting rock, how could I know if it comes from space or not?

For example, this US Gov website https://www.usgs.gov/faqs/i-think-i-found-meteorite-how-can-i-tell-sure outlines some features of meteorites, but how can you definitely be certain that it is from space? Are there any tests or specific features that are unique solely to meteorites and can not be present in any other rocks on Earth?

I'm a beginner, and don't know much about this hobby to be honest, but I think that you as an expert by now would have your own methods :)

Thanks.

 

[davenn]

Hey @davenn, you really have an intriguing hobby!

Thanks ... it is so cool

But I am wondering, how do you differentiate, how do you know that the rock you find or buy is really a meteorite? I have tried Googling this, but it's really quite generic. For instance, when global sellers ship them to you, how do you know that you are not being tricked? ;)

if it is a relatively fresh fall .. less than around 1000 years, it will still have some or all its fusion crust as in the 1.5 and 5.25 kg examples above. The fusion crust will dull with time and erosion. Other features on the surface also show it to be a meteorite rather than an Earth rock ... Orientation = obvious flight direction markings that show the way it came through the atmosphere, Regmaglypts = those hollowed out depressions, also known as thumbprints.
Internally Ordinary Chondrites are VERY different to Earth rocks ... they have a nice sprinkling of metal throughout them and little spherical chondrules that is not seen in any Earth rocks ...
eg, these 2, from my collection ... a Western Australia one and a Canadian one

easily seen chondrules in this one from Morocco

The difficult ones to differentiate from Earth rocks are the Achondrites, and most of them need to be
analysed to get mineral content to determine their origin. Many Achondrites are breccias and look just like Earth breccias ... like this breccia from the Moon ...

The other 2 main types, the Irons and the Pallasites also have distinctions not found in Earth material

All but a small variety of iron meteorites ( from an asteroid core) show a distinctive crystalline pattern with the iron and nickel.
This is called the Widmanstatten Pattern is easily seen wen an iron meteorite cut surface is polished and etched with acid ...

Pallasites are iron meteorites from the asteroid mantle layer ( surrounds the core). they have a nice mix of iron/nickel and olivine. Pallasites are called stony-irons

 

[davenn]

. For instance, when global sellers ship them to you, how do you know that you are not being tricked? ;)

I only buy from trusted sellers ... Sadly, there are many people selling Earth rocks as meteorite
I belong to a number of Facebook groups that have good trustworthy hunter, collectors and sellers and we are all quick to denounce any fake sellers

And if I were to go on a walk in the Outback and find an interesting rock, how could I know if it comes from space or not?

First, visual observation experience, then testing. ~95% of the time, breaking/cutting a rock to see the interior will instantly determine if it is a meteorite. The other ~ 5% of the time it will need lab. testing

For example, this US Gov website https://www.usgs.gov/faqs/i-think-i-found-meteorite-how-can-i-tell-sure outlines some features of meteorites,

That's reasonably good ... but the magnetic thing is a catch with many newcomers ... Not all meteorites will be attracted to a magnet. and there are a lot of Earth rocks that will be attracted to a magnet. It isn't a reliable test

but how can you definitely be certain that it is from space? Are there any tests or specific features that are unique solely to meteorites and can not be present in any other rocks on Earth?

Read the stuff I have posted in the previous post :)

I'm a beginner, and don't know much about this hobby to be honest, but I think that you as an expert by now would have your own methods :)

Skilled, Yes, but I don't claim to be an expert ... there are many in my circle of meteorite friends that know much more about the subtleties than I do. But I am confident that I could, just visually ( external view) identify around 80% of meteorites, seeing the inside would add another 10 - 15 %. the other ~ 5% I would need to see a lab analysis

cheers
Dave

 

[pinball1970]

"if it is a relatively fresh fall "

I thought you were going to say, "like last week/month/ year!"

Do you ever get requests from Unis or private research labs for samples? On your face book page/other?
Some pretty old stuff in meteors as well as clues to how abiogenesis may have got started.

I may have asked you about Murchison before