If you are interested in cleaning your family cemetery stone, the Cemetery Commissioners have successfully used D/2 Biological Solution on their own family stones.

D/2 Biological Solution is specially formulated to remove environmental pollution, dirt, and staining from biological soils such as mold, mildew, lichen, and algae from indoor and outdoor surfaces. D/2 is a Biodegradable cleaner that is pH neutral and contains no salts, bleach, or acids. It is highly effective for removing stains caused by biological growth on surfaces including marble, granite, limestone, masonry, concrete, wood, canvas, and vinyl & aluminum siding. It will not damage glass, metal, or plants.