actually thermoplastic polyurethane is very great material and can protect your device by hard impact.but main problem is dust or quartz particles....because Corning gorilla glass have maximum scratch protection to 6.4 hardness measures according to mohs scales of hardness...quartz or sand have 7...,so none of the gorilla glass withstand to scratch by sand particles 👍
Btw the solution for your issue is Lamination, Laminate your phone (or get it done by any shop near you) and then you can use any case or cover of your choice. (One thing I wanna mention here is Lamination isn't something to consider if you are a **bleep** user or mobile gamer because it CAN trap the heat inside your phone and alter the performance a little bit).
