Thread: ID this pretty rock for me?

I found this in my childhood home while cleaning out the basement. I recall my dad using it to sharpen kitchen knives. Its entirely possible that this may have even belonged to the G-dad I never met. It may be horribly dished, and I doubt its a finisher, but I would love to know for my own knowledge, what kind of stone this may be. Its pattern is pretty distinct, so I'm sure one of you guys will have a good idea!