Shiny slag/rock, unidentified??

[Rarecoins]

Hello! Found this today.
Most definitely not a rock due to the possible air bubbles (maybe some slag of some type)
Very sharp and tough (couldn t cut a section). Not magnetic. Found next to some old settlements.
Also tried melting a very little piece with a propane torch. Got it red but not melting, so high melting point.
I previously found some more but little pieces only, this is quite large. The AT pro was giving mixed signals.

Thank you for your consideration!

 

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[against the wind]

Melted Wreckage from an Alien Spaceship,,

 

[islamoradamark]

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[ToddsPoint]

Just a guess. Corundum. It even looks a lot like synthetic corundum. Gary