Really need help identifying these

[Cassidyrose]

I found these today while collecting quarts next to a creek in pennsylvania. They're dark green and at first I thought they could be glass but I'm not sure because of how thick they are and how they're shaped. I tried scratching glass with them and it barely leaves a mark, just slightly. Could these be gemstones or are they just glass?

 

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[ToddsPoint]

It looks like glass slag the came from an old iron furnace. Just a guess. Gary

 

[Cassidyrose]

Thanks for the response! You're probably right