if you mean leaving it out in the sun....then you should just buy some base rock cause you would just kill of any life and coralline algae. You need to keep the rock wet and in saltwater, heated water to be clear, with circulation. You cure live rock to get all the stuff that has died due to shipping of the rock before you put it in your tank so your levels dont spike. If you just left it out in the sun, if that is awhat you mean, then it wouldn't be live rock anymore plus who knows what kinda land bug would make it his new home and then be put into your tank.