Found blue rock. Anyone know what this is?

[MimiG]

Found this digging into the hill on our property. We have done many searches on the internet but can't seem to find anything. Any info is much appreciated.

 

[smokeythecat]

That's man made slag from a furnace. See the air bubbles where it melted off? Some people make jewelry out of them.

 

[MimiG]

Tried to reply but it didn't show. Was hoping for something more exciting but furnace slag makes a lot of sense. Thank you for the help.

 

[CRUSADER]

Yeap, slag glass mix.