What material is used to make the second hand in an oyster perpetual steel watch?

[Coolshades]

Does anyone know what material is used to make the second hand on an oyster perpetual steel watch? I’ve always heard the markers are white gold and I assumed the hands were probably white gold as well. I was recently scrutinizing a relatively new oyster perpetual 39 mm steel watch at an AD. They said they sold it originally and someone traded it back in. It appeared to have what looked like rust on the second hand. You could not see it with the naked eye. I didn’t buy the watch. Is the second hand made out of steel on steel watch? I was concerned either it had some non-Rolex parts or it had some water intrusion at some point. Has anyone else seen this before? Thanks.