That $10,000 Android we looked at a couple weeks back, the Vertu Ti, might not have been the most impressive phone in the specs department, but it did have one killer feature: a screen made of synthetic sapphire. Single crystals of aluminum oxide like this have a Mohs scale hardness of nine, meaning you’re going to need something in the same league of hardness as other sapphires or diamonds in order to scratch them. At the MWC this year, we got to check out a demonstration of just what kind of damage sapphire ...