Cerium oxide. The trick to making it work is the right pad and using LOTS of water. I am talking spray bottle in one hand and polisher in the other and you spray it after every pass. It doesn't break down like a normal polish so you just re-wet it to keep working it. It can be done with a DA, but expect to spend some time on it.
So much this! OEM glass is always better than aftermarket glass. No stupid blue streak at the top and they seem to hold up better.