Anyone know what this is?

[mdevanitz]

I was walking down the street in the suburbs of Pittsburgh. I found what I think is Agate. It is slightly magnetic.

 

[PamDF]

Ummmm hard to tell by the pic. any closer up higher resolution shots?

 

[austin]

Slag?

 

[DDancer]

Either a green granite or quartzite with magnetite *the black bits*. Quite possibly just a bit of old decorative masonry considering where you found it. Good bit for the collection though.