Help id rock? plz

[colllt45]

hi
need help if rock. Located vacant farm northeast ne braska. Nonmagnetic, won't scratch, very heavy about size of basketball but weighs about 100lbs, also very sharp cut my hands lifting it, very shiny inside primarily green and black.

 

[Champ Ferguson]

Looks 'glassy'- would you agree with that description?
By 'wont scratch' I assume you mean with a knife? Try scratching with a piece of quartz if you have one.
Hold a fragment up to the light and let us know if you can see light coming thru it.
The broken areas appear to be conchoidal in shape...?

My first thought is obsidian.
As always, if you have a convenient sized piece of it, I recommend you take it to your local community college and search out a geology prof- that is the easiest way to get the best id. After that, take it to a gem/mineral show- they often have a table with local experts for identifying things the public brings in. Its very hard to get it right by just looking a picture on the net, even if we all agree on what we see.

 

[Johnho]

That's a good one for sure. I can't find any references to naturally occurring obsidian in Nebraska. Did find where the Indians made things from obsidian however. Where they got it who knows. I agree though, it does look like obsidian or some glass type material.

 

[Sovguy]

Iwould suspect some type of agate, however, the weight is off for all of these.
Railroad slag or somethi g with pyrite in it could be in this catagory. Only other thi gs that might be in that catagy of weight would be meteorite, lead ie galena, or some metal ore or slag.
Best to find a.rock saw or knock off a piece with a hammer and have someone in the know.look at it

 

[Champ Ferguson]

1 post driveby. I wonder why these folks even bother.

 

[Johnho]

Yup, seems to be a lot of that. I find it on other sites too. You give an answer and nadda.