When visiting a gravesite, my Jewish relatives always place small stones on the gravestone as a showing of respect for the dead. They typically place one stone on the gravestone, but I find myself wondering how many stones is a visitor expected to place on a gravestone. Is there a minimum or maximum count? Is it considered disrespectful to place too many or too few?
Orach Chaim 224:12 Beer Haitaiv 8 says the reason that either grass or stone is placed on the grave is as a honor for the person buried there, as it shows that people came to his grave. There is no mention as to placing more than or less than one.