Charzardite location

okay so i got a delta bulbasaur as my starter but i just got a normal charizard. is there a way to get a charzardite even though i didnt get it as my starter? it doesn’t matter which one i just want a mega charizard

You have to trade for one. Or make a new game in purity and play till you get the stone and have someone help you trade it between accounts. As of now, only charizardite Y can be obtained.