Identify mineral / semi-precious stone?

[Michael88]

Hi!

Maybe someone knowledgeable about stones and minerals can help me here, I'd like to identify what I have found in Iceland on the edge of the Vatnajökull glacier. It kind of looks like green stone but I'm not sure. The deposit feels like glass, is teal colored and nontransparent.

Thanks in advance!

(Size reference, the small stone is a little bigger than my thumb)

 

[Danoff]

Green Obsidian?

 

[turbolefty78]

I think it's this stuff: Volcanic Glass
There's many different hues depending on the impurities that were with the silica as it was being melted way back when. Notice that not every specimen is clear. Some are opaque like your's is.