Please be very careful with these old headstones. Many of them are very porous and brittle. It's easy to accidentally scrub the surface right off. Here's some information off the net... From http://www.hollyhockfarms.com/coweld/cemetery/cleaning_gravestones.htm Approach each project, no matter what material the grave marker is made of, by asking yourself, 'what is the gentlest means possible? The harshest, quickest, or cheapest method is often not the gentlest. And, certainly, blasting with chemicals, sand, pecan shells, glass beads, or even water is not the gentlest means possible. Make test patches of your proposed cleaning technique on an area of the structure that is least visible. Begin with plain water (at garden hose pressure) and a soft bristle brush. You will find that some foreign materials are removed quite satisfactorily with this simple approach-dark algae from a marble surface, for example. Should further action be needed, the next step should be the slow and cautious addition of a mild detergent to the water. However, before any detergent is added, the stone surface should be thoroughly soaked with water, again at garden hose pressure. It takes time to thoroughly soak stone-thirty minutes minimum, and some sources recommend soaking a stone for 24 hours! The reason for the soaking is to make sure that the detergent is applied only to the surface of the gravestone; if not thoroughly saturated, the stone will absorb the detergent, making it impossible to rinse away. It is very important to understand that acids are very damaging to marble and limestone, and chlorine bleach (such as Clorox and Purex) is very bad for almost all stone, including polished granite. Many people have totally lost the polished face of a fine granite marker by conscientiously scrubbing with household bleaches. If you feel you need something in addition to a mild detergent, use a diluted solution of ammonia (1 part ammonia to 3 parts water). You can also try a photographic solution named Triton X, which is recommended by conservators as a gentle cleaner. Water and gentle scrubbing should do the job. Keep in mind that a soft-bristle brush is all that is needed. Metallic brushes are entirely too harsh, and they also leave particles on the surface of the stone that can rust. Always watch carefully to make sure that none of the stone's surface is eroding as you scrub. From http://www.cemeterypreservations.accessgenealogy.com/custom4.html DO NOT DO ANY OF THIS TO HEADSTONES: Shaving Cream: DO NOT USE SHAVING CREAM TO READ HARD TO READ HEADSTONES. Most people who have some experience in the area know that this is not a good practice and by doing so you can cause irreparable damage to the stone itself. Shaving cream, of all kinds, contains perfumes and stearic acid. Stearic acid is a white crystalline fatty acid obtained by hard fats which is used in creams for scar and skin lesion reduction. This acid is stronger than acid rain. 3xs stronger to be exact. Some shaving creams, such as Gillette Series line, have replaced stearic acid with palmitic acid, which is somewhat safer for your face but still has the same effect on stone. Shaving cream contains chemicals, greasy emollients that are sticky and very difficult to remove from the stone with a simple washing. The cream fills the pours of the porous stone as a result will discolor and damage the stone. DONT USE SHAVING CREAM, CHALK, GRAPHITE, DIRT OR OTHER CONCOCTIONS IN AN ATTEMPT TO READ WORN INSCRIPTIONS. Why not use the safest cream? To begin with, the exact formula in shaving creams are corporate trade secrets. ALL creams cause the surface to exfoliate (scale, splinter). Marble and Limestone are highly reactive to acids, and will actually sublimate in the presence of hydrochloric acid. That means it will go from solid to a vapor with out a liquid stage as it releases certain parts of its chemical structure. All chemicals in shaving cream are biodegradable. Since they are biodegradable, they provide food for microscopic organisms, fungi, mosses, etc. Only completely chemically inert materials should ever contact a tombstone. The residue from Styrofoam inert, therefore not chemically damaging. The only problem with this is the pressure being applied to the stone may cause damage. When pressing on old stone it tends to crumble. DO NOT DO ANY OF THIS TO HEADSTONES: What About Rubbing Headstones: Headstone rubbings is another problem. Some people rub chalk directly on the stone and some use paper and black chalk. This is a good method but has a lot of serious problems. When attaching the paper to the stone to get a proper reading you must do this with tape which leaves residue behind and when the initial tape is removed it also takes particles from the stone. The pressure on the stone, especially an old stone, is damaging. You may think that the amount of pressure you put on the stone didnt cause any cracks but it weakens the stone from the inside and at the base. Papers carry chemicals which bonds the particles of the paper together, you dont think its just cut that way from a tree do you. I have seen people apply regular street chalk directly onto stones, which causes damage itself. No matter what the package of street chalk says, it DOES NOT wash way with the next rain. Take some of this chalk out to your street and make a mark you will see that after the next rain it is still there. If this chalk is applied to the stone and the sun shines on it for a period of time it stains the stone that color. God made the weather unpredictable. ALL stones have pores, and this chalk gets into those pores and DOES NOT come out no matter the amount of water that is used. Best way to read warn inscriptions would be foil and a very soft bristle brush. Best foil would be the cheapest you can find. Why? The expensive foils are made to be tough, cheap foil isnt. Why a soft bristle brush and what is the best kind? A soft bristle brush with at least a 3 inch handle is time consuming to use due to it being soft but absolutely no pressure is applied to the stone. The best to use is a paintbrush. A brush with a flat handle is very uncomfortable for the hand to hold for long periods of time and does require pressure that you might not know you are using. For more information on best ways to read hard to read stones please see our How To page for some great tips that we personally use as well as those from experts that have been in working with stones for almost 20 years. Rubbing Dirt Into The Stone For A Better Reading: Some use dirt as a highlighter. Why not, they say, the stone has been in the same elements as the dirt. Granted this is true, but you were to remove a stone and look at the damage that occurred to the portion under ground you would be able to see that it is deteriorated. This is why a lot of stones fall from the base. By rubbing dirt into the inscription you introduce microscopic organisms, fungi, mosses, etc., which deteriorated the base and will do the same to the rest of the stone. Bleaching: DO NOT BLEACH ANY STONE PERIOD!!!! Yes bleaching will kill fungi, moss and other organisms but it will damage the stone. ALL bleaches contain Sodium Hypochlorite, which is an unstable salt. This will eat its way into the stone even if completely cleaned. Bleaches also contain Chlorofluorocarbon. This is a gaseous compound that contains carbon, chlorine, fluorine and hydrogen, which is used in refrigerants, cleaning solvents and aerosol propellants. The problem with that mix is the hydrogen. Every one knows that hydrogen is a gas. When applied to a surface it turns into a flammable liquid. Which is why it removes stains so well and is also highly lethal. This will cause the stone to liquefy in a very short time. What About Using Graphite? Graphite is a carbon substance. Graphite is used in pencil lead and carbon paper as well as in batteries because graphite contains Sulphuric Acid. Sulphuric Acid is a heavy CORROSIVE oily oxidizing and dehydrating agent. I think corrosive explains enough on why not to use Graphite. We want to save these stones not have them fall apart in our hands.