Anyone know what this could be?

[-=METAL=-]

Hey guys,

This belongs to a friend of mine. He got it from his sister, but she is no longer around to answer questions about it, so I don't have any background information on it, or know where it came from. Is it anything significant?

 

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[BurntBear]

Appears to be slag glass to me.

 

[BenjiDaa]

I would agree.