Copper slag?

[agbkyle]

Hi, I'm new to this forum. I'm from Southeast Mass. Found this next to a river in the woods.
Rang up as copper and is green so I'm assuming it is copper.
Just wondering how to tell if it's an artifact or the result of a melted copper blob.
Search on the internet for "copper slag" shows a couple like it and they're in museums.
Thanks for any info

 

[Cannonman17]

It does look like slag, I don't know why they would have slag in museums though unless it was a mining museum? The natives didn't smelt/refine their copper by heating it to the melting point so this slag you found must be from historic times.

 

[greg0074]

I found something similar in one of my fields: http://www.treasurenet.com/forums/rocks-gems/294793-solid-copper-rock.html#post2784556

 

[Monette]

It's copper if it's heavy enough, and sometimes you can fit a big of copper color showing through the green. It does appear to be a little too rough to be float copper, but that would be my first thought. The natives sometimes melted down copper pots to reshape into tools but I don't think it would turn that green that fast.