/diy/ - Do It Yourself

Surely there are some chemists here that can answer my question. I etched some steel a while back using salt water and a battery charger. I left the container to sit for a couple weeks and when I came back the particulates in the water had settled to the bottom. I was wondering what this greyish green-blue stuff is exactly. This is what made up the bottom layer and on top of that was a very thin layer of rust, and on top of that is some very acidic water. Oh yeah, I guess I should mention I used iodized table salt in case that has anything to do with it.