Torture, supposedly, brings out the truth.
At the forefront is Marques Brownlee (aka MKBHD), who obtained what he alleges is the type of screen Apple is currently inserting into its (probably) larger phone.
First, he raked a knife over it. But knives are, in the vast screen of things, soft.
Now, Brownlee is back with what he says is an even truer test of the screen's durability.
In a new YouTube video, he takes two types of sandpaper and rakes them over the screen. He also explains that with the iPhone 5S, the home button is already pure sapphire, so raking over that would help too.
That's where he starts, using garnet sandpaper. The home button of the 5S, which he says is pure sapphire, is left pristine. The screen of the alleged iPhone 6 shows some scratches.
But then he goes for the big one -- the emery sandpaper. It wrecks the iPhone 5S's Gorilla Glass. The sapphire screen does better, but is still, in Brownlee's words "not indestructible."
Brownlee's conclusion is that the alleged screen of the alleged iPhone 6 is allegedly a sapphire composite, not the pure thing. This allows for flexibility, as well as durability.
"As long as you're not carrying high-quality sandpaper in your pocket, you should be good," is his charming conclusion.
Having bathed in all this reassurance and knowing that even if you're a carpenter you'll keep your sandpaper well clear, Brownlee's video ends with one more torture test.
Now this one is just plain mean.