Mystery Rock???

[pyrate]

hello!

I found this rock in my back yard and cleaned it up. I live in Reno NV

I have looked at the library in all their books and I cannot figure out what this is....I'm hoping one o fyou will solve the mystery....I put a regular sized coffee cup next to it to give some idea of size.

Thank you!

Attachments:

[charlieb]

It looks like glass slag. The one on the right, correct?

Chuck

[leonardo]

Correct...

[pyrate]

Thanks you guys!~
No wonder I couldn't find it in the library...LOL...I feel very silly now.
Thanks for your help. I do appreciate it!