LWilson181@aol.com asks: "Are these "don'ts" based on real data or just passed down opinions garnered by someone else?  If they are based on real data, please provide the location so I can go there and read it for myself" A number of articles can be found on About.com about cemetery preservation. You can read those articles and assess the validity of the authors' credentials by going to: <A HREF="http://genealogy.about.com/cs/cemeterytips/">http://genealogy.about.com/cs/cemeterytips/</A> Several articles speak to the use of shaving cream and one explains thusly: ......To begin with, the exact formulas for shaving creams are corporate trade secrets however, it is common knowledge that most contain emollients to soften the skin, while at the same time protecting it. Shaving Cream also contains a chemical known as stearic acid (defined by Britannica.com as "a c olourless, waxy solid that is almost insoluble in water") which will  cause the surface of the stone to exfoliate, especially if that stone is either granite, marble or limestone. Granite is an igneous rock, and therefore highly susceptible to any type of chemical weathering. By putting shaving cream on the stone, you are doing the same thing acid rain does over a long period of time, only you are hastening the destruction. Marble and Limestone are highly reactive to acids, and will actually sublimate in the presence of hydrochloric acid. That means it will go from a solid to a vapor without a liquid stage, as it releases certain parts of its chemical structure. Further reason for not using shaving cream lies in the potential damage over a very long period of time, not just a few years. The chemicals in shaving cream will permeate into the microscopic pores of the stone and will not be readily washed out. These chemicals, which consist of soaps, mineral oil, fatty alcohols and other skin conditioners are all organic compounds which are biodegradable. Since they are biodegradable, they provide food for microscopic organisms, fungi, mosses, etc. The growth of such organisms in the pores of a stone causes expansive forces which will gradually cause microscopic particles of the stone to be flaked off. These enlarged microscopic pores can also collect moisture in wet freezing weather and the freezing action causes microscopic fractures of the stone because, as you know, water expands upon freezing. In other words, only completely chemically inert materials should ever contact a tombstone.... Gail