Something weird happening to my Xperia Z1's aluminium frame since 2 months ago. I begin to notice there are some dark spots or pitting on the bottom right of the aluminium frame. Now those dark spots are appearing even more. I tried using my fingers to feel those dark spots and it feels like when I'm scratching a corroded steel
Coincidentally, those dark spots appears in the area where my hand usually touch the phone. I live in a tropical country and this probably happens because my sweat somehow harm the aluminium frame. Anyone experiencing this issue? And does anyone knows how to make these dark spots gone?