What scratches glass--or is it glass?

[Burning Petard]

I turned in a rental car yesterday after driving it for two weeks. It was a '21 Toyota Corolla. ALL the windows were scratched. To me, the scratches looked like straight lines, mostly horizontal, and some vertical. They showed up with the sun shining directly on them at particular angles. To my not-perfect sight, without measurement or calibration they seemed to be about 2-4 inches long and none curved. A brief on-line search said the outer layer of auto glass was glass, but very thin. Years back, my son who was much more technically informed than me about many things, told me to be very careful with ice scrapers, because the plastic was now harder than the outer layer on auto glass. The web also says these scratches probably can be fixed. I suspect the rental company will do that, but wait till they are ready to sell the car.

Never have I scratched the windows on my car. It this stuff something other than glass? Can auto glass be scratched by something with a mohs hardness rating less than diamond?

snailgate

[Jarlaxle]

Sand on window glass will do it. Grit in wipers. I replaced a window on a car I owned because the glass was badly scratched from rubbing a worn door seal going up and down.