Cast iron is not only very hard, it's extremely durable. Ever have a cast iron skillet? One of those that is well taken care of can last a lifetime. How do you take care of one? Season it by coating it with cooking oil and heating it in an oven for about 30 minutes. That will develop a non-stick surface that will also protect the skillet and will build up as you fry things in it.
It is important to season a skillet again every now and again should you see rust start to develop.
Still, cast iron makes great cookware that requires very little maintenance. It doesn't do well in a dishwasher, however, as the seasoning can get washed off and rust can develop. Using a scouring pad on cast iron cookware is a bad idea, too.