Hannibal has become somewhat of an expert on death markers. He discusses his work at the museum February 5 in "Rocks of Ages: A Geological Look at Gravestones."
His study emerged from this burning question: Why are there so many marble monuments throughout the Midwest? Hannibal chalks up the white stone's dominance to a 19th-century Greek revival and its easy import via Ohio's once-booming canal system. (Granite became prominent after folks were able to manufacture the tools necessary to cut the hardy stone.) "In Cleveland, you see all this gleaming white marble when you drive by," he says.
Hannibal's work, compiled with the aid of students from local universities, looks at a variety of factors in tombstone aging. If you want your stone to last, stay away from the city: The report, published this past September in the Ohio Journal of Science, presumes that gravestones in urban areas are eight times more likely to weather than gravestones in rural areas.
"If you drive by a cemetery, you can almost date it just by zipping by," says Hannibal. "You develop an eye for it." According to his dead reckoning, you can approximate date of death like this: sandstone prior to the 1830s, marble between 1830 and the late 1800s, and granite from the late 1800s to the present.
Though his study is principally a scholarly endeavor, Hannibal promises that his discussion will not be pedantic, and that there will be something for the whole family. "It's rated 'G' for gravestones," he quips.