Lost something special in the trash! HELP!!!!! FAST!!! PLZZZZZZZ!?

OK, i have a dog who loves to eat Kleenex... i know, weird... yes, the Kleenex out of the trash can.so i bought a little trash can for my room, you know the kind with a lid on it. well, he found out how to get it open! so i took a rock that we got from the S. part of mexico (its painted) and that rock is very special and i put it in the garbage on top of the Kleenex. and it worked! but the sad thing is, i for got that it was in there and accidentally collected the trash and put it in the dumpster. and by the time i remembered it, it was too late!! :( so what should i do if i want it back??!!??