A Tumble Surprise

[mn90403]

The last few months I haven't been out nugget hunting.  I've been on the beach and a couple of parks.  My posts have been in the jewelry forum.

It was time to tumble those coins and clean them up for use and maybe see if there was a missed silver.  I have 'limited' shelf space to keep things and I sometimes just pour things together waiting for a time to tumble.  Last night before I went to sleep I did my 3rd tumble and just dumped a cup of stuff into it and got up this morning to take a look and dry the coins.  Well I had stuck in a few crusty pieces of jewelry and a couple of odd finds that were not iron.  I don't remember where I got them or when. 

After I saw the result of the tumbling I was amazed at one of the pieces.  The weight is 12.8 g and I went and air tested it on my Nox and it says 11.  Neither of these things jogs my memory as to where I got it.  I do know I had saved this piece and a couple of other 'hot rocks' that were odd to me and they weren't magnetic.  There is a 'chance' even that I got this nugget on a beach and that was the reason it has the green color.  I just don't recall and I don't think I took a picture of it with my 'finds of the day' which I often times do.  I would rush out to my coin dealer with an XRF gun and get the analysis but I think they are closed because of the pandemic.

When I picked it out of the coins (after 5 hours) this morning and saw the polished parts and then still the other parts holding the green I was reminded of both gold and copper.  I think it may be mostly copper and didn't polish more because it is hard but I also think the density is greater than just copper.

What are your thoughts on the mystery nugget?  I've included different angles.  Don't restrict your thinking to just beach finds.  This could also and I think more probable that it is a desert find that I saved but the corrosion ...

 

[Hardtimehermit]

Looks like bronze, strange little nugget as if it was bronze slag? 

[mn90403]

1 hour ago, Hardtimehermit said:

Looks like bronze, strange little nugget as if it was bronze slag? 

You may be right.  My wife now thinks I probably found it on the beach as she doesn't remember me showing her after a desert hunt.

It didn't have any of the gold color parts on it when I found it.  Those are the tumble marks.

[normmcq]

 Looks like copper to me, do a specific gravity test and let us know the results.

                                                                                        Norm

[GB_Amateur]

Questions are easier than answers, so I'll start there:

specific gravity?

What's the melting point of copper, bronze, brass?  Are beach campfires hot enough to melt them?

There are many copper minerals and also (quite a bit less common) native copper.  Gold nuggets naturally occur in an infinite variety of alloys.  Is the same true for copper?

Green is telltale for copper compound (copper sulfide?  One of those compounds).  Malachite is a copper mineral which shows that very color.  I'm tossing in my vote/guess that it's a naturally occurring copper nugget, but an alloy, not pure copper, and you found it inland.  (Oh, and if I'm right, an S.G. test it should give a result around 9.)

I think Occam's Razor favors a natural solution.  It appears to me to have been worn down over a long period of time.  I suppose that could happen on a beach, but how long would it take?  I don't think you can compare this to aluminum, which is quite soft in pure form (e.g. store bought aluminum foil) and also easily(?) melted in a hot fire.

P.S. is that dime silver, and was it a surprise find from your tumbler?

[1515Art]

Mitchel, looks like copper to me too, I got one exactly like it one time sans the green oxide from a bag of lynch paydirt. Cool find anyway will be a mystery as to it’s origins.

[mn90403]

14 minutes ago, GB_Amateur said:

P.S. is that dime silver, and was it a surprise find from your tumbler?

It was in the same tumble but it is not silver.

[normmcq]

 Pure copper melts @ 1984 degrees F,  wood campfire about 1100 degrees F. Oxyacetylene torch about  6000 degrees F. A coal forge about 3500 degrees F.

Melted copper nuggets fairly easy to make, a smooth copper nugget, I think would have to move quite a ways to change from a naturally occurring nugget 

                                                                         Norm

[1515Art]

I don’t know how they come to be (all smooth and polished) ive seen them by the boxes in gift shops selling nature and holistic Stuff too, shop down by the beach in Capitola sells them.

[GB_Amateur]

42 minutes ago, 1515Art said:

I don’t know how they come to be (all smooth and polished) ive seen them by the boxes in gift shops selling nature and holistic Stuff too, shop down by the beach in Capitola sells them.

Well, maybe it is man-made.  A rock tumbler with abrasives added can wear things down a lot faster than mother nature.