Mohs Hardness Scale and Phones

Youtube is flooded with phone gadget reviews, everything from "Top 10 Waterproof Cameras" to "Which Keyboard Cover to Buy". But one day as I was scrolling through the comments section of an iPhone screen protector I say a post by a very agitated individual. The comment was something like:

You stupid &^!@* why are you supporting the *!&@^ companies who make these glass protecters from beer bottles and charges us SO MUCH! They don't even WORK!

The ranting and swearing went on for some time, but the important part of the comment is:

I got this exact screen protector and when I was at the beach I brushed some sand off my phone and it scratched the @&^$# protector!

This comment really made me angry, not because of the swearing or anything, but because I understood the reason behind the scratches and it has nothing to do with the company that makes them. He might as well have said: I smashed my iPhone with a sledgehammer, now it doesn't work! Apple sucks. Here's the reason his screen got scratched.

All materials have different hardnesses. There have been various scales developed by different people but the most common and universal one is the Mohs hardness scale. It was developed to rate mineral hardness, but it can be applied to everyday materials too. The scale goes from 1 to 10 and a material can get scratched by anything equal to or harder than itself.

 Now according to this picture, glass has a hardness of around 5.5. Sand is made mostly out of quartz, which has a hardness of 7. Now is clear why the guy scratched his new phone protector when he brushed off the sand. It is simple not possible to make ordinary glass harder, so even the world's top screen protectors are no match for sand. Apple is developing sapphire glass, which is made of aluminium oxide. Aluminium oxide, aka corundum, ranks at number 9, making it immune to sand. Perhaps one day we will have sapphire glass screen protectors?

Image Citation: N.d. The Mohs Scale of Mineral Hardness. Web. 9 May 2016.