Uneven color of frost?

[JJH]

Is the 22K gold coin easy to oxidize? Under strong light, I found that the color of the frost surface on the coin is different, at the bottom of the nose and the corner of the mouth across the cheeks, and there are some on the neck, but under non-strong light, the same part (the bottom of the nose and the corner of the mouth across the cheeks) seems to have the same horizontal lines, but it's not a scratch, does anyone have this uneven color in the cream, or is it a fingerprint? But I'm not sure