Thread: Stone Id

I bought a stone at a flea market yesterday and I could use some help identifying it. Sorry for the bad pics the only camera I have is an old digital. The stone is light green with a pattern and is very smooth it is about 2 1/2 x 6 and an inch thick. It seemed hard but when I sanded the surface a little with 600 grit it was chalky. Slury is same color as the stone. Any idea what grit it would be? Seems like maybe ten K. Thanks for any help you can give me. It is lighter than the pics show.