what metals don't rust
Steel rusts because it contains iron. Iron decomposes over time when it comes in contact with oxygen. Gold, silver and platinum are all pure metals that don't contain iron and, therefore, don't rust. Stainless steel doesn't rust because it is an alloy that contains the metals chromium and nickel. Chromium must comprise at least 10 percent of the steel alloy for stainless steel to be rust resistant.