Marble tombstones are a beautiful choice for marking the graves of loved ones. White marble tends to look dirty and stained after being exposed to the elements, however. One of the worst things you can do is to grab a household cleaner and a wire brush and start scrubbing. Cleaning marble headstones takes a gentle hand and patience.
Inspect the marble tombstone for damage. Look for flaking, crumbling, previous repairs, surface fractures and cracks. Don't try to clean the tombstone if the marble has deteriorated in any way because it could cause even more damage.
Saturate the marble tombstone with water at least 30 minutes before cleaning it. This will help prevent any cleaning solution from leaching into the marble and will also loosen up any grit or grime.
Scrub the marble tombstone with a soft-bristled brush dipped in clean water. Brush in a circular motion to remove more dirt. Clean the headstone from the ground up and rinse often so the dirty water doesn't leach into the marble and cause staining or streaking.
Gently scrub off any algae, moss or lichen with a brush or a soft piece of wood. Keep wetting down the marble so this process is easier. Rinse the tombstone thoroughly with the hand-pump sprayer or a new sponge dipped in clean water.
Spot treat any remaining stains with a non-ionic detergent. These detergents have a neutral pH that shouldn't harm marble. Follow the manufacturer's directions to prepare the cleaning solution. Scrub the stains gently with a soft-bristled brush or a new toothbrush.
Clean the etched features of the marble tombstone with a toothbrush dipped in clean water. Scrub gently so you don't damage the marble. Rinse the gravestone thoroughly.
Do not use hand-pump sprayers with a water pressure above 30 psi. This type of sprayer wears away the marble around carvings, etchings and inscriptions. Do not use abrasives or household cleaners. These can streak, stain or yellow the marble.