Hello, recently on my phone (iPhone 5) some black dots and scratches started to appear on the edges and on the back of the phone. They look dirty, but it's not. I don't know how they came about. I usually carry it with a case and I've never dropped it. I searched the internet for how to remove them and found that they are removed with Sandpaper. If you know how, please help, because they look very ugly when I remove the case. I have never seen a phone like mine with such black scratches on the internet. Please give advice on how to remove them.