Well, nuts

After my shave tonight, I noticed a small spec of black on the back side of the blade of my 4 month old Dovo Bismarck! It's not huge, doesn't effect performance and doesn't look like rust. Maybe some sort of either waterspot or one of those black mystery spots.

From reading in the past, everyone has recommended some metal polish...so off to get my simichrome I went. After a careful application so as to not get any on the gold, I started working...but it didn't come off...<sigh>

I don't think it's much to be worried about, but want to confirm it with you guys.