Blame It To The Sand! Screen protectors aren't as necessary as they once were, but they can still be useful. Glass screen can still get scratched with the sand in your pocket, and can crack if you drop your phone. Yes, you read it right. SAND. Most modern smartphones use scratch-resistant glass on their screens, but every once in awhile you'll see that your phone still gets some fine scratches. It's not the coins or the keys in your pocket, it's the sand. There was an experimentation with a number of screen protectors, which use tempered glass to keep scratches off your phone. They test it against keys, coins, sand, and other materials to see what scratches it the most. Surprisingly, most materials didn't leave a mark, but that hard, gritty sand that's floating around in your pocket—or on your desk, or anywhere else—actually has the potential to leave some scratches in your phone, showing us that screen protectors can still be useful. The bad news is that tempered glass protectors are also fallible to the same issues, but it's far easier to replace the glass protector than your phone's screen itself. If you've had one too many scratches in the past, it's a good way to protect your phone and get that superior glass feel.