RIA nickel plating issue?

[Delta959]

So I picked up a new RIA matte nickel 1911 (my first 1911) and, after I cleaned it, took it out to put 50 rds. It ran great and was super accurate! BUT after I got home I noticed that the front strap was discolored and starting to turn black! I tried cleaning it off a little and that didn't really do much. Any ideas of what to do?

 

[simonm2211]

Ammonia?

Did you use a solvent containing ammonia to clean it?

 

[Delta959]

Nope, made sure I got something that didn't. It was almost instant. I suppose I just have some potent sweat that tarnishes the nickel.

 

[RockyMtnTactical]

pics?