Vandals sneak into cemeteries under the cover of darkness and overturn markers or spray paint them, but the community's most upstanding citizens do their damage in broad daylight, often receiving the approbations of those who see them.
Who are these tombstone abusers? They go into cemeteries armed with Comet cleanser, Brillo pads, bleach, stiff-bristled brushes, rubber gloves, and other cleaning agents to clean markers and spiffy them up.
If rocks could speak, they would cry, "Ouch!"
Tombstones may be made of rock or metal, but they can't stand up to that kind of abuse.
If your ancestors' grave markers are dirty or decaying, you may want to contact the Association for Gravestone Studies. This organization publishes annual journals and has a bi-monthly newsletter. Among other things, the newsletter gives valuable advice on cleaning gravestones.
It supports preservation, conservation, and restoration of gravestones and archiving information about them and their sites. It also encourages education and historical interpretation.
A rose is a rose, is a rose, is a rose, but a headstone isn't just another rock. Markers may be slate, granite, marble, soapstone, limestone, slate, or a variety of other rocks. Not even all marble is alike, or all granite. The type of stone affects cleaning.
And let's not condemn all cleaning. Lichens not only turn white marble stones black, they can damage the strongest stone. Yellow-orange colored lichens can be especially bad and should be removed.
If you visited family graves over the Memorial Day weekend and noted markers in need of attention, by all means, go back and clean them. But please be gentle. No stiff-bristled brushes. Stone, and even bronze, is more fragile than we imagine. Most soaps contain acids that eat away at them, dissolving stone and pock marking metal--especially in concert with acid rain.
However you clean, your last step should be a thorough rinse with clean water, preferably distilled water, to wash away the acids.
If you want your family's markers to last a long time and retain legible engraving, treat them more like precious jewels than like rocks.
Some folks think that since shaving cream is so soothing on the face, it would be gentle to rocks. Not so. Shaving soaps contain harsh acids as preservatives. When mixed with water, they can cause marble and limestone grave markers to fizz away like a slow-acting Alka-Seltzer.
"A Graveyard Preservation Primer," by Lynette Strangstad, explains about shaving cream:
[indent block]"Our professional conservators tell us it is definitely not a good idea to use shaving cream on porous gravestones because there are chemicals, greasy emollients, in shaving cream that are sticky and very difficult to remove from the stone with a simple washing. Indeed, even with vigorous scrubbing and lots of rinsing, the cream fills in the pores of a porous stone and cannot all be removed. The result of leaving it there is that in time it may discolor or damage the stone."[end indent block]
I'm told chalk, talcum powder, and some other chemically stable salts make good cleaners because their composition is very similar to marble and limestone.
Special caution is in order for cleaning old slate stones used in some parts of the country, especially if they've been exposed to acid rain.
During prolonged exposure to acid rain, old slate stones tend to form layered sheers with air pockets between the layers. Any kind of physical contact with the stone itself can cause damage.
Some suggest only professionals should clean markers. Unfortunately, marker care and preservation is such a new interest, there may be no true professionals anywhere, much less one in your neighborhood. Local stone cutters may be able to provide advice, but still be cautious. Even these experts may not give sound advice for care and restoration. If their advice doesn't include cautions about damage, find another expert.