Cleaning Gravestones, Monuments & Stone Sculptures ...
A short list of cleaning techniques based on stone type. Listed in order from the safest, or least aggressive, to the most aggressive: Slate: Clean water, non-ionic detergent,biocide solution. Sandstone: Clean water, non-ionic detergent, biocide solution. Marble/ Limestone: Clean water, non-ionic detergent, biocide solution, ammonia and water solution