... scientists can actually come to conclusions about environmental pollutants, weather patterns, acid rain, etc. in an area based on the wear patterns/deterioration levels of old tombstones? It really is a fascinating science.
I've noticed in my community, even at cemeteries that are only 15-20 minutes away from each other, some tombstones of the same age are worn differently because of the cemetery's proximity to a facility that pollutes, or because the lay of the land allows for greater weathering. There are even lesson plans out there for teachers to use to teach kids of all ages the significance of certain wear patterns and what they mean about the pollution and weather in the area. These lessons allow for educators to take their students to cemeteries so they can learn first hand. So cool, from an educators stand point. Here are some links about the science of gravestones and teaching others about the science:http://www.livescience.com/18681-cemetery-gravestones-weathering-acid-rain.html
http://connections.smsd.org/csi/GRAVESTONEWEATHERING.pdf
http://www.msnbc.msn.com/id/46545861/ns/technology_and_science-science/#.UEA4itZmSIA
http://www.ehow.com/info_8147762_effects-acid-precipitation-gravestones.html
I know more articles are out there, but this is a good start!