# I may have found a couple of meteorites

#### zoobyshoe

It just scrapes away with sandstone or clay below. Why are you so interested in the third one? That surely isn't a candidate for anything interesting.
It's native metal of some sort, that is not iron. That interests me. All kinds of metals might be found in sandstone. Gold, copper, silver, platinum metals, uranium, to name some I've read mentioned. It might be something boring like lead or tin, but it might not.

#### DaveC426913

Gold Member
Ever though of doing any panning for gold in that stream of yours?

#### physics girl phd

Yes I did, but the first time I tried it on somewhat coarse cement and saw nothing. Last night I decided to take the suggestion from the page and tried it on the inside of the toilet lid. This time there was a distinctive gray streak. This suggests that it's magnetite. But the streaks were light gray, not dark gray, so I'm going to hold out for the density test before calling it a wash. At this point, unfortunately, I would have to say they are likely magnetite.
Is there anyone else that finds a streak-test on a toilet a bit disturbing?

I guess this relates to my loss of interest in a lot of geology... in 8th grade science, my teacher passed around rock and mineral samples and encouraged students to taste the salt chunk (about the size of a small child's fists. Well, JoJo P (the student sitting next to me) plopped the whole thing in his mouth and slurped on it for a good long while before slopping it back on the tray (covered with his saliva) and passing it to me.

I'm recovering interest, albiet slowly (and thank goodness I guess in that I had a fair amount of pre-knowledge going into 8th grade that didn't get cleared by the experience). Not sure streaks on a toilet helps here though...

#### Ivan Seeking

Staff Emeritus
Gold Member
Is there anyone else that finds a streak-test on a toilet a bit disturbing?
At least they don't call it a skid test; where you check for skid marks!

Apparently the streak test is a standard technique, and the inside of the tank lid is just the right type of surface and ceramic. Given that toilet tank water is considered an emergency supply of drinking water, it's not THAT bad.

Dave, I've had a guy pushing me to work this creek for gold, for years. He offered to do the work for half the take, assuming there is any. That sounded pretty good to me. Last time he was here he took a bucket of black sand to sift for traces. So far I haven't heard anything.

#### FlexGunship

Gold Member
The joke was that, eventually, I'm gonna rebuild that truck!
Every time I rebuild a carburateur I seem to have pieces left over. I figure it I do it enough times, I'll finally just have two carburatuers.

Given that toilet tank water is considered an emergency supply of drinking water, it's not THAT bad.
Yeah... but, I mean... it's not just for emergencies. Right?

#### FlexGunship

Gold Member
Like an idiot, I totally missed those pictures before! That's crazy, I have a rock I tucked away from when I went hiking in Vermont. I took it because I specifically remember thinking it looked like a meteorite. It looks a lot like your's Ivan. No joke. It, too, was magnetic, but that's as far as I got.

Time to check closets. We can compare notes.

#### Borek

Mentor
On the other hand, vinegar can be turned into very weak hydrochloric acid just by adding common table salt.
I wouldn't say so. Yes, you will have both H+ and Cl- in the solution, but calling it hydrochloric acid is wrong.

There are two important properties of hydrochloric acid - it is strong (that is, its is almost 100% dissociated and its solutions contain a lot of freely available H+) and it contains plenty of Cl- (important when dissolving metals easily complexed by chloride ions - iron included). Solution of NaCl in vinegar will contain a lot of Cl-, but concentration of H+ will be just that of acetic acid. It will not behave like hydrochloric acid.

#### zoobyshoe

I wouldn't say so. Yes, you will have both H+ and Cl- in the solution, but calling it hydrochloric acid is wrong.

There are two important properties of hydrochloric acid - it is strong (that is, its is almost 100% dissociated and its solutions contain a lot of freely available H+) and it contains plenty of Cl- (important when dissolving metals easily complexed by chloride ions - iron included). Solution of NaCl in vinegar will contain a lot of Cl-, but concentration of H+ will be just that of acetic acid. It will not behave like hydrochloric acid.
I believe you, and am not really surprised popular explanations would end up calling it by a misnomer. I suppose the important questions are 1.) will it dissolve (or "etch") metal in the way Ivan wants, and 2.) what should I call it if I ever refer to it again?

#### Ivan Seeking

Staff Emeritus
Gold Member
I guess this relates to my loss of interest in a lot of geology... in 8th grade science, my teacher passed around rock and mineral samples and encouraged students to taste the salt chunk (about the size of a small child's fists. Well, JoJo P (the student sitting next to me) plopped the whole thing in his mouth and slurped on it for a good long while before slopping it back on the tray (covered with his saliva) and passing it to me.
This reminded me of something I saw on The Naked Archeologist. He did a show on ancient artifacts from the Middle East. Fake artifacts are big business and it's easy for tourists to get duped. In conjunction with a noted collector, the narrator/scientist explained that one can easily check for age by doing a taste test. If something is truly old, it will taste salty. I mentioned this to the owner of PF when he went to Egypt but he didn't seem too interested. Maybe he didn't want to go to a Egyptian jail for licking artifacts in public...?

#### Ivan Seeking

Staff Emeritus
Gold Member
I wouldn't say so. Yes, you will have both H+ and Cl- in the solution, but calling it hydrochloric acid is wrong.

There are two important properties of hydrochloric acid - it is strong (that is, its is almost 100% dissociated and its solutions contain a lot of freely available H+) and it contains plenty of Cl- (important when dissolving metals easily complexed by chloride ions - iron included). Solution of NaCl in vinegar will contain a lot of Cl-, but concentration of H+ will be just that of acetic acid. It will not behave like hydrochloric acid.
Which apparently answers the question of whether sodium acetate is soluable in HCL. I thought it might form a precipitate.

#### Borek

Mentor
I believe you, and am not really surprised popular explanations would end up calling it by a misnomer. I suppose the important questions are 1.) will it dissolve (or "etch") metal in the way Ivan wants, and 2.) what should I call it if I ever refer to it again?
1. I doubt. Too weak acid.

2. Just a mixture of acetic acid and NaCl.

There are cases when such mixtures have properties different than just a sum of components, two most obvious cases I can think of are Aqua Regia and fluorides dissolved in hydrochloric acid. But in both cases there is some additional chemistry involved, there is no such thing in the acetate/HCl mix.

Which apparently answers the question of whether sodium acetate is soluable in HCL. I thought it might form a precipitate.
Presence of HCl may slightly change solubility of acetate, but for all practical purposes it will be still highly soluble salt.

#### zoobyshoe

Borek, I tried the "cleaning the penny" routine. I found three pennies that were equally tarnished. I kept one as a "control", put one in vinegar, and the other in salt and vinegar. The one in salt and vinegar started to brighten up almost immediately. The one in vinegar alone seemed to do nothing at first. As I kept visually comparing it to the "control" I could eventually see it was slightly brightened. The one in the salt and vinegar won hands down, however, and after 5 minutes looked nearly brand new.

The mix of salt and vinegar is distinctly more powerful in attacking copper oxide.

Thoughts?

#### physics girl phd

Ivan Seeking;3526895}...Maybe he didn't want to go to a Egyptian jail for licking artifacts in public...?[/QUOTE said:
Mmmm...time to lick the mummy found in the streets of Peru, age unknown. :yuck:

As an aside, salt and vinegar is often a pretty good cleaning agent for pots/pans. I always thought the abrasiveness of the salt was helpful, but I guess it must be the chemistry as well... guess this is when you get to used to using an old trick and never think about it.

#### zoobyshoe

As an aside, salt and vinegar is often a pretty good cleaning agent for pots/pans. I always thought the abrasiveness of the salt was helpful, but I guess it must be the chemistry as well... guess this is when you get to used to using an old trick and never think about it.
I stirred till the salt was all dissolved and simply dropped the penny in. There was no scrubbing necessary for the tarnish to clear up.

In the meantime I hunted up a good, rusty old hinge and put that in salt and vinegar. It seems to have no effect on common rust whatever.

#### Borek

Mentor
The mix of salt and vinegar is distinctly more powerful in attacking copper oxide.

Thoughts?
It still doesn't mean you can call this mix a hydrochloric acid solution.

I know the effect, I am using it by myself, but I am not sure about the chemistry. Cu+ is complexed by chlorides (much more strongly than Cu2+). My guess is that oxides on the copper surface contain enough Cu2O that presence of chlorides increases the dissolution kinetics and shifts the dissolution equilibrium to the right, making the process much faster.

I will try to dig something more.

#### zoobyshoe

It still doesn't mean you can call this mix a hydrochloric acid solution.

I know the effect, I am using it by myself, but I am not sure about the chemistry. Cu+ is complexed by chlorides (much more strongly than Cu2+). My guess is that oxides on the copper surface contain enough Cu2O that presence of chlorides increases the dissolution kinetics and shifts the dissolution equilibrium to the right, making the process much faster.

I will try to dig something more.
I'm curious because the reaction is very definite and fast.

I scraped the edge of one of the pennies with a file and put it in the vinegar/salt. It sent up a nice little plume of bubbles from the nick. I assume it is reacting with the zinc inside the penny. (Our pennies are copper plated zinc.)

However, the reaction with steel is disappointing. A few little bubbles form here and there, is all.

@Ivan.
I was out of pool acid anyway so went to Home Depot and got some. It is, with tax, $10.75 for two gallons. (This seems to be the minimum quantity they sell; a box containing two one gallon jugs.) It reacts pretty strongly with steel. There's a lot of bubbling and smelly fumes. Still, for all this activity it's not removing material from the screw I put in it very quickly. It may take a lot longer for it to "etch" one of your samples than I thought. #### Ivan Seeking Staff Emeritus Science Advisor Gold Member I'm curious because the reaction is very definite and fast. I scraped the edge of one of the pennies with a file and put it in the vinegar/salt. It sent up a nice little plume of bubbles from the nick. I assume it is reacting with the zinc inside the penny. (Our pennies are copper plated zinc.) However, the reaction with steel is disappointing. A few little bubbles form here and there, is all. @Ivan. I was out of pool acid anyway so went to Home Depot and got some. It is, with tax,$10.75 for two gallons. (This seems to be the minimum quantity they sell; a box containing two one gallon jugs.)

It reacts pretty strongly with steel. There's a lot of bubbling and smelly fumes. Still, for all this activity it's not removing material from the screw I put in it very quickly. It may take a lot longer for it to "etch" one of your samples than I thought.
If the density of the stones check out I will dig around to find the suggested concentration of HCL.

My scale is supposed to be delivered on Monday.

I keep wondering if I can hook up with someone at the University and have it checked with a mass spectrometer. I don't know how big of a deal it would be to have it checked properly. That is the definitive test if you happen to have one handy.

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#### Borek

Mentor
I'm curious because the reaction is very definite and fast.

I scraped the edge of one of the pennies with a file and put it in the vinegar/salt. It sent up a nice little plume of bubbles from the nick. I assume it is reacting with the zinc inside the penny. (Our pennies are copper plated zinc.)
Gentle people of CHEMED-L helped to locate a paper in Journal of Chemical Education - Laurence D. Rosenhein, "The Household Chemistry of Cleaning Pennies", http://pubs.acs.org/doi/abs/10.1021/ed078p513 - basically it confirms my intuition that it is just a correct pH and presence of Cl- that promotes creation of Cu(I) complexes.

#### zoobyshoe

Gentle people of CHEMED-L helped to locate a paper in Journal of Chemical Education - Laurence D. Rosenhein, "The Household Chemistry of Cleaning Pennies", http://pubs.acs.org/doi/abs/10.1021/ed078p513 - basically it confirms my intuition that it is just a correct pH and presence of Cl- that promotes creation of Cu(I) complexes.
You're saying the presence of the acetic acid creates the proper pH for the Cl to bond with the Cu in the oxide?

If so, this makes a lot of sense. I realized last night that my experiment was incomplete in that I hadn't tested a penny in salt solution alone. I dissolved some salt in water and put a penny in. Nothing much happened, and I forgot about it. This morning, though, I found that the penny was very much cleaner than the "control".

Salt alone, it seems, will clean a penny, but it takes very much longer. The vinegar really speeds the reaction up.

(The salted penny, though, has a strange color now. I almost wonder if the black oxide wasn't replaced with the red oxide.)

Anyway, thanks for digging that abstract up.

#### Ivan Seeking

Staff Emeritus
Gold Member
The scale arrived yesterday.

I show the large stone at 3.4 +- 0.2 grams/ml

The small stone comes in at 3.0 +-0.6 grams/ml

The volume measurements were a little crude, which is what mostly limits the accuracy for the small one. For the large one I was able to check the mass of the displaced water, which allowed for greater accuracy.

http://epswww.unm.edu/iom/ident/index.html [Broken]

these would appear to be stony meteorites. Hematite and magnetite both have a density of about 5 grams per ml.

Here is part of the problem from a practical point of view. Some people spend years trying to find a meteorite. I found the large one in about fifteen minutes. But I did only get three hits on the detector over about 300 feet of creek bed packed with rocks. I just can't believe I could walk out and find one that fast. The odds against it would seem to be astronomical.

The guy who loaned me the metal detector has been looking for one for over three years.

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#### Proton Soup

i wouldn't expect to have much luck at all where i live. this whole area is covered in iron ores. i remember playing with magnets as a kid, and just raking a dry sandy spot of dirt would net several tiny pieces.

#### zoobyshoe

The scale arrived yesterday.

I show the large stone at 3.4 +- 0.2 grams/ml

The small stone comes in at 3.0 +-0.6 grams/ml

The volume measurements were a little crude, which is what mostly limits the accuracy for the small one. For the large one I was able to check the mass of the displaced water, which allowed for greater accuracy.

http://epswww.unm.edu/iom/ident/index.html [Broken]

these would appear to be stony meteorites. Hematite and magnetite both have a density of about 5 grams per ml.

Here is part of the problem from a practical point of view. Some people spend years trying to find a meteorite. I found the large one in about fifteen minutes. But I did only get three hits on the detector over about 300 feet of creek bed packed with rocks. I just can't believe I could walk out and find one that fast. The odds against it would seem to be astronomical.

The guy who loaned me the metal detector has been looking for one for over three years.
The density looks right, but since they didn't pass the streak test I wouldn't be confident until I was sure they had some nickel in them.

Have you gone out prospecting any more, or did you return the metal detector already?

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#### Ivan Seeking

Staff Emeritus
Gold Member
The density looks right, but since they didn't pass the streak test I wouldn't be confident until I was sure they had some nickel in them.

Have you gone out prospecting any more, or did you return the metal detector already?
This is the really freaky part. It only works intermittantly. That day was the only time that I've gotten it to work reliably. I suspect the wire going from the coil to the body has an issue and I was going to try to fix it, but the coil and the main unit look like they're sealed. It is designed to be waterproof. So I may try to get another one.

Note that technically they didn't fail the streak test. It wasn't dark gray or red. At most a light gray. And that was to rule out magnetite and hematite, both of which are conclusively ruled out by the density. At this point I may pay a visit to the local University. I don't want to guess about the next best move.

I'm tempted to run over to the rock shop and have it cut in half, but I'd better not... just in case that's a bad thing to do for some reason. I'm sure this is nothing special, maybe worth $100-$200 from what I've seen, but at this point I'd feel better about checking with the local expert before I do anything destructive.

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