One interesting stone

I'm posting two photos of something interesting I stumbled upon. I'm not sure if it's 'just a stone' or an implement - perhaps a stone axe or celt.



This picture is of the flip side and is a close up of two very small grooves that run up and down the middle of the stone.



I turned the stone back over and left it exactly as I found it. If anyone has any ideas, please post a comment - thanks!