Meteorites and tektites

[Gareth_]

There was recently a thread about tektites which has motivated me to makes this thread..... they're not fossils but they do have a place in my cabinet and they are very interesting! It's not every day you can hold something 4.5 billion years old

I won't go in to detail about the types of meteorites and the classes within the individual types - it gets confusing and I only know enough to get by. There are 3 main types - stony, stony/iron and iron. 

Tektites are ejected terrestrial material from an asteroid or comet impact, thought to be once sedimentary rock that has turned in to a natural glass due to heat and pressure. 

 

On the pic showing many items...

Top left 296 grams / 10.4 oz iron meteorite - Campo del Cielo 

Top right 13 grams / 0.46 oz iron meteorite slice, acid etched to show the Widmanstatten pattern (please look this up if you have a spare minute - the reason for this pattern is amazing).

Middle right - North West Africa (NWA) L Chondrite 13 grams / 0.46 oz. This is a stony meteorite, "L" meaning Low iron content. In one pic you will see small areas of black on this meteorite, this is fusion crust. Fusion crust is the melted exterior of a meteorite that was in direct contact with the atmosphere.

Bottom - tektites. The 2 on the right are translucent, I have one of them sitting on my ring light (and black cloth covering as much direct light as possible so it doesn't white out the camera - messy pic but the result is good!)

 

 

 

 

  

 

 

  

  

[Gareth_]

I used to own these too, unfortunately they started to rust and the repair job was more than I wanted to take on I so sold them.

These are Pallasites, a stony/iron meteorite. Roughly 50/50 meteoric iron/olivine crystals. Pallasites are a very rare type of meteorite.

Unfortunately these photos don't do them justice - do an image search for Pallasite and see what they should look like!

 

Sericho Pallasite slices. I forget the weight of them, 50-60 grams if memory serves. 

[Fossildude19]

They are impressive looking!

 

Last set, brightened:

 

 

 

 

 

 

[Misha]

Nice little collection!

I have some tektites myself and find them quite fascinating.

I've wanted to add some meteorites to my collection, especially pallasite but I am worrying about the potential of rusting

Do you do anything to protect the iron meteorites from rusting? 

[Gareth_]

17 hours ago, Misha said:

Nice little collection!

I have some tektites myself and find them quite fascinating.

I've wanted to add some meteorites to my collection, especially pallasite but I am worrying about the potential of rusting

Do you do anything to protect the iron meteorites from rusting? 

Thanks!
From what I've read, the Sericho pallasites are known to rust so I'd stay away from them, no matter how tempting a slice looks!

The little slice I've had for years and I've done nothing to it, it came in a little display container sitting on wood shavings and that's how it sits in my cabinet. The nickel content must be high enough to "rust proof" it. 

The Campo del Cielo I bought last weekend, it was recommended I coat it in oil which I'll do

[Wrangellian]

This topic has prompted me to go look at the Sericho slice that I 'de-coated' this past summer -at the expense of a lot of effort and some electricity- because it was rusting despite the epoxy coating. It came out looking not great. My Muonionalusta piece also was threatening to rust, so I put them in ziploc bags (the Muon double-bagged) with dessicants. No such luck. Maybe the dessicants were already saturated, I dunno. I'll show pics soon if anyone's interested. I don't know if there is much an average person like me can do. I have one more trick: I got me one of them heat sealers, and will try sealing them in plastic. But I don't have much hope... If the epoxy did not protect them from rusting, then a sealed bag probably won't help. But I'll try it and report back later.

[kgbudge]

4 hours ago, Wrangellian said:

This topic has prompted me to go look at the Sericho slice that I 'de-coated' this past summer -at the expense of a lot of effort and some electricity- because it was rusting despite the epoxy coating. It came out looking not great. My Muonionalusta piece also was threatening to rust, so I put them in ziploc bags (the Muon double-bagged) with dessicants. No such luck. Maybe the dessicants were already saturated, I dunno. I'll show pics soon if anyone's interested. I don't know if there is much an average person like me can do. I have one more trick: I got me one of them heat sealers, and will try sealing them in plastic. But I don't have much hope... If the epoxy did not protect them from rusting, then a sealed bag probably won't help. But I'll try it and report back later.

 

I'm a little surprised that a nickel-iron meteorite would rust noticeably. Is this common?

[Wrangellian]

16 hours ago, kgbudge said:

I'm a little surprised that a nickel-iron meteorite would rust noticeably. Is this common?

Not only did it rust, but it rusted inside the epoxy coating that was supposed to protect it, and of course continued to rust after I removed the epoxy. I thought metal needed to be exposed to water and oxygen to rust, and I thought epoxy would make a good seal, if nothing else would.

I don't know how common it is but apparently it's common with these Sericho slices.

[Gareth_]

18 hours ago, kgbudge said:

 

I'm a little surprised that a nickel-iron meteorite would rust noticeably. Is this common?

I believe it depends on how high the nickel content is.

As I said above, my little iron meteorite slice has not been treated with anything and it's still as shiny as the day I got it! I'm not going to push my luck and dip it in the ocean haha.

My pallasite slices rusted, it's possible the weather conditions were poor the day they were resined (raining, humid day) and sealed in moisture. Once rust starts, it's very difficult to stop.
Conditions at home should be considered too.... I live really close to the ocean (I'm near the end of a narrow peninsula approx 14km long) and Auckland city is known for humidity. None of that helps in slowing corrosion of iron. I keep my fossils/meteorites in a cabinet with a few moisture absorbing packs in it and they're in a part of the house which is the most temperature stable (cool in summer, warm in winter).

[Bone Daddy]

Sericho can be stable when prepared properly. Encasing any meteorite in a clear poly is a bad idea and rarely ends well. These specimens look a lot like the large numbers of budget-priced Sericho specimens being sold on online out of China. They are sliced and then sealed in some sort of clear resin or polyurethane. They are not polished, etched, or properly dried before the sealant is applied. That's why you can still see the saw marks on the slice under the resin. Moisture is trapped inside the matrix of the specimen and it starts to "bloom" out later - the most stubborn areas are the boundaries between the metal matrix and the olivine crystals. Since the moisture cannot outgas, it starts to spread throughout the specimen until the whole thing rots under the resin. Eventually the resin is the only thing holding the piece together. Remove the resin and the specimen may fall apart. This could be avoided by purging the moisture out of the specimen using a hot oven before applying the sealant. Using tap-water as a saw coolant also introduces contaminants that can accelerate the oxidation process. If one corner has been cut, then probably every corner has been cut throughout the entire preparation process. 

 

Sericho is a high weight recovery. Lots of it was found and some of it is inherently more stable than other pieces. The stuff coming out of China was bought cheaply, prepared cheaply, and sold cheaply. The vast majority of it is going to end up rusted.

 

The key is proper preparation (just like with fossils). I live in Florida and have had pallasite slices in my collection for years without any major rust issues. Imilac, Esquel, and Seymchan are usually considered quite stable. Brahin, Pallasovka, Admire, Brenham, and others are considered rust-prone. But, with proper preparation, even the rust-prone ones can be mostly stable.

 

Nice pieces. Thanks for sharing them. 

 

 

[Gareth_]

@Bone Daddy Thanks for your comments and I totally agree. Since I sold them I have found out pretty much exactly what you've said about poor prep, done on the cheap in China.
It's a real shame because so much, very rare material is going to become worthless rust because some people wanted to make a few quick bucks and cut corners. You can't just go and dig more up, what's here is here! 

When I bought them, I did wonder why they were unusually cheap.  A local seller brought a bunch of them in.... and yes, he did not coat them in resin, it was done before it came in to NZ. 

Ah well, I did lose a bit of money on them but not too much, I on sold them with full disclosure - that money helped to buy a Carcharodontosaurus tooth

 

[Tyrannosaurus Rex]

Hello guys,

 

I was thinking about opening thread regarding meteorites,but I didn't because this is mainly forum for fossils and I wasn't sure will others approve it.

Anyway,I always wondered are those cheap meteorites that are being sold within shops that also sell fossils authentic or not?

I heard that few grams can cost insanely high,but then again,those are sold for less.

Also,I recently saw few of those packages that supposedly contain authentic Moon particles,or even tiny fragments from Mars. But I hardly doubt it's anywhere near genuine.However,they are sold as ''genuine'' and company that sells them should need to have some kind of proof they are legit,otherwise it's plain illegal selling of fake items right?

It would be so awesome to actually own fragment that traveled so long in space before Earth even formed.I get chills by even thinking about it.

 

 

[Gareth_]

@Tyrannosaurus Rex Go for it, we're in a "Rocks and Minerals" section of the forum now.... this forum is mostly about fossils but not entirely! 

I'm not familiar with what is being sold in your local shops... what type of meteorites are they? Some are fairly cheap, the type of meteorite is one large contributing factor to cost. For eg a NWA chondrite will fetch significantly less money than a (as a random example) Campo del Cielo of similar weight. 

Moon and Mars material would be exceedingly rare, I'd tread with a lot of caution around items like that. In my opinion, you're best to focus money on a real meteorite, not unverified dust.  

 

I know what you mean about owning something so old, it is really cool knowing this is the oldest thing I can own and where it came from! 

What photos don't show is the weight. Sure you can read the weight I posted and see the pics, but when you hold that small mandarin sized meteorite and feel the weight of it, they're much heavier than they look! .....and so they should be, it's a solid chunk of iron haha 

 

[Tyrannosaurus Rex]

1 hour ago, Gareth_ said:

@Tyrannosaurus Rex Go for it, we're in a "Rocks and Minerals" section of the forum now.... this forum is mostly about fossils but not entirely! 

I'm not familiar with what is being sold in your local shops... what type of meteorites are they? Some are fairly cheap, the type of meteorite is one large contributing factor to cost. For eg a NWA chondrite will fetch significantly less money than a (as a random example) Campo del Cielo of similar weight. 

Moon and Mars material would be exceedingly rare, I'd tread with a lot of caution around items like that. In my opinion, you're best to focus money on a real meteorite, not unverified dust.  

 

I know what you mean about owning something so old, it is really cool knowing this is the oldest thing I can own and where it came from! 

What photos don't show is the weight. Sure you can read the weight I posted and see the pics, but when you hold that small mandarin sized meteorite and feel the weight of it, they're much heavier than they look! .....and so they should be, it's a solid chunk of iron haha 

 

Well,in my country (Croatia) they don't sell any types of fossils or meteorites.

I was thinking about buying them from some stores online that have great reputation for authentic items.

The one I saw and mentioned are from one small shop in UK,but I saw them in similar stores for similar price.

I would be happy to own or even touch anything that came from outer space,so type of meteorite alone is not a big factor for me when it comes to buying them.By far the most important thing is authenticity.Other thing that would be nice is it's old,but that's not very important either, only authenticity.

 

I think I can imagine how heavy they are despite being so small.

I have small piece of raw iron and when I look at it,it looks fairly light,but when I pick it up it's much, much heavier than someone would think at first sight.

Do you think that any type of meteorite would cost as little as $15 tho?

Despite being some "irrelevant" type,it's still very rare thing to find and I don't know why would anyone sell it for that price?

I saw fossils that can be easily found in just a few minutes on certain locations of course,but then again there are so many fossils that very common and you have to search for meteorites a lot and you don't even have formations or something that would easily point out where they are.

I never understood that situation to be honest.

 

 

[Bone Daddy]

I cannot speak for all meteorite dealers, but there is a lot of genuine lunar and martian meteorites floating around in collections and dealer inventories. I own some myself. Yes, there are fakes on the market. The best advice is the same you hear for fossils - do your homework and know your seller. Reputation is everything. Provenance is important. 

 

I bought my first meteorite back in 2007 for $5. There are many common types of meteorites that are quite cheap. Unattractive, weathered, common chondrites can go for less than a dollar per gram. Rare types or localities can exceed $1000 per gram. It just depends on the type and other factors such as market demand. Pallasites are prettier to look at, so those usually fetch a premium for properly prepared specimens from desirable localities. Market fluctuations can also impact prices.

 

For example, in 2007 the retail prices for lunar meteorites often exceeded $1000 per gram. There was far more demand than supply. In the years since then, a number of large lunar finds were recovered out of the Sahara. These new finds flooded dealer inventories and the market, depressing prices. You can now find genuine lunar for about $100 per gram retail. I can buy it wholesale for a fraction of that. These prices were unheard of just 5-7 years ago. 

 

If a newbie collector wants to ensure they are getting genuine meteorites (and not misrepresented Earth rocks), then it's best to avoid unknown sellers. Find a dealer with an established history of honest trading and start there. I wouldn't blindly trust search engine results or auction site searches. Find a veteran collector in a forum (like this forum) and have them point you to some trusted dealers. From there, you can start learning the market and build a legit collection without the doubt that comes with bargain shopping from unknown sellers.

 

Edited January 8, 2022 by Bone Daddy

[JohnJ]

Even though this is the Rocks & Minerals subforum, all the same rules apply as far as mentioning any dealers or specific pricing.  Discussions to that level of detail should be via PM.  Thanks.

[Bone Daddy]

On 1/8/2022 at 8:06 PM, JohnJ said:

Even though this is the Rocks & Minerals subforum, all the same rules apply as far as mentioning any dealers or specific pricing.  Discussions to that level of detail should be via PM.  Thanks.

My apologies. I thought it was OK to talk about the market in general terms without mentioning any specific pieces or dealers. Feel free to edit as needed. 

 

[JohnJ]

27 minutes ago, Bone Daddy said:

My apologies. I thought it was OK to talk about the market in general terms without mentioning any specific pieces or dealers. Feel free to edit as needed. 

 

Mike, your general synopsis of the market is fine.  My comments were a precaution.  Most of the time when pricing gets tossed around in a topic, we have to edit the inevitable specific references to dealers and their prices or locations.