I'm not a geologist, but I know that sandstone is formed of loosely compressed layers that flake easily - as anyone can see by looking at old gravestones make of sandstone. I saw some up in Knox Co. that had the faces completely flaked away - fortunately someone had transcribed the information before it was gone. Perhaps the geologist didn't realize the fragile materials that were sometimes used - if everyone had used granite or marble, we wouldn't have the problem! I respect people's need to read what's on the ancestors' stones, but they won't be there for the next generation if we aren't careful. Joanne Gaudio