If it had gorilla glass Jiayu would have mentioned it on their site given that it is a big selling point.
http://www.ejiayu.com/en/Product-19.html
Anyway, my G2S dropped from about 120cm high flat on its screen on hard floor and it did not break. Pure luck I guess.
I guessed so as well, but thought it worth to ask those who already have it. Anyhow GG doesn't protect from breaking when dropped, but very resistant to scratches.