I bought a wok today and used it for the first time, I washed it before using it and it kept its beautiful grey/waxy sheen inside and out. I made fried rice using a metal wok spoon and then ate, after washing the wok I noticed the grey sheen is gone wherever I used the spoon and all I see is metal on the whole bottom half of the wok. It does flake off pretty easy with my finger, I think the wok is made from carbon steel and I bought it from this chinese restaurant supply store. I'm really worried, I hope it doesnt participate in me getting stomach cancer. Please help!!!!