Today I was talking to someone who told me he used a small marble slab as a finishing stone for his straight razors. He said it was 3" X5" and was polished on one side. He also stated that it gave him really smooth edges on his razors. He seemed to be genuine (he knew a lot about finishing stones), but I have not heard anyone mention marble here on the forum. I'm still relatively green when it comes to finishing stones so I couldn't say. Is Marble a good medium to use as a finisher?