The stone countertops are places on the cabinets and, after ensuring that everything is leveled, a bead of silicon is applied at the intersection of the cabinets and the underside of the stone. This is sufficient to hold the countertops in place in a normal situation.
If the cabinets are not leveled, which is not uncommon, we have to place shims underneath the countertops to level them. In this situation our installers place small blocks of wood pieces rinsed in epoxy to stabilize the shims.
Learn more about how granite countertops are installed here.