The others have basically answered your question, as to what it is called... Nitron.I have been googling trying to find what kind of finish is on Sig Sauer pistols. I haven't found a definitive answer, but the closest I can find is "superblack'. Is that correct?
I'm also trying to find out if the finish can be touched up, if there is a way to minimize wear marks myself without spending much $ and also if CPO pistols refurbished at the factory have the finishes restored.
I guess you can tell that I'm looking at used guns...
Thanks.