The first gorgon with the ability to turn you to stone was once you reach Hades, towards the beginning of that level. (At least it was for me, I was playing Normal difficulty, I don't know if you encounter tougher enemies sooner on Hard and above) What you want to do is quite simple, wait until it's one on one, killing off any enemy that might interfere.
Afterwards, simply bait it until it fires off it's beam at you. Stand still for a few seconds until you're stone, then mash L1+R1 to break free. You're gonna want to do it relatively quickly, since if you get struck while petrified you'll die. Do this 5 times in a row, and the trophy is yours. Good luck!