FMF - Friends of Minerals Forum, discussion and message board

[Eduardoo]

Dear Friends:

I got this nice chunk of copper, should I clean it or leave as is for display?

I know it is a sin to clean a coin, and cleaned coins are less valuable. What about minerals?

If it should be cleaned, what is the best way to clean copper?

Regards,

Eduardo

[GneissWare]

You will see many cleaned (acid dipped) coppers available for sale. But, once it is cleaned, you loose the patina of the copper and the associated secondary minerals. Once cleaned, you can't restore it.

I tend to not chemically clean coppers. Ultrasonic cleaning is fine for me, but I don't like the bright copper look.

[Jordi Fabre]

[Eduardoo]

Thanks for your comments. I actually find the green rust quite appealing, so I will just leave the piece alone.

BTW, I am not sure wether my piece is massive or crystalized Copper (I have never seen Copper crystals before), I would appreciate your comments.

Regards,

Eduardo.

[John S. White]

Eduardo:

It is a little difficult to tell absolutely from a photo, but your copper does not appear to exhibit crystal forms. On one side it looks like platy copper that has been precipitated between pebbles in a conglomerate or fragments in a breccia. If you do not understand these terms, you can find good definitions on Wikipedia. My guess is that this is massive copper.

Do not forget that when submitting such questions, it is important to provide as much information as you can. You did not tell us where the copper is from, what locality? If you don't know the exact locality, you might at least know the country where it was found. Even that could help.

[Les Presmyk]

My first impression was that this specimen may actually be a smelter product. In which case, using the various cleaning methods will be fine.

[Eduardoo]

Hi John:

Here are two close-ups of the Copper. Maybe that would help to determine if there are crystals.

The Copper is from Perú.

Regards,

Eduardo.

[John S. White]

Really hard to say. I am waiting for Alfredo to weigh in on this one.

[Les Presmyk]

Can you take a similar close-up of the other side?

[Eduardoo]

Sure, this is the back.

[Les Presmyk]

I still question whether it is natural or something resulting from molten copper from a smelter or other refining process.

[Jordi Fabre]

[Eduardoo]

My copper specimen looks a lot like this one: wwwdotjohnbetts-finemineralsdotcom/jhbnyc/gifs/48856dothtm

It is described as a hackly mass of copper, so I guess there are no crystals.

[GneissWare]

This is a pretty typical specimen of copper--its attractive and has a nice patina.
Crystallized copper is relatively rare, and commands higher prices. Lots of the copper from Michigan and even Arizona looks a bit like your specimen. Enjoy it..