This is a practice that is being banned in some states and in many cemeteries. Connecticut has particular problems because of the many gravestones that are sandstone. These stones will erode internally leaving the surface (that has hardened over the years due to environmental exposure) seemingly very stable for rubbing when in fact the stone is hollow beneath. The pressure of wax rubbing or cleaning can cause the stone to fracture or implodecausing irrevocable damage to an historic artifact. Many cemeteries now ask for permits before you are allowed to do rubbings - check this information out in advance.
Teachers - Please seek advice before taking a group of school children out in an old graveyard to do rubbings. There are many ways to work with children of all ages using an old graveyard for your resource. Many of them are virtually “no cost” activities.
For more information, contact CGN.