CLEVELAND, OHIO—An analysis of fossils embedded in nineteenth-century millstones in Ohio shows that many of them were made of imported materials. The popular stone, known as French buhr, originated near Paris, France, even though it resembles Ohio chert, also known as flint. The French stone is made from rock derived from freshwater deposits, and can be identified by fossils of a type of algae that occurs in the rocks of the Paris Basin and freshwater snails. Ohio chert contains saltwater marine fossils that are older than the ones in French buhr. “Based on the stones we have examined, it is clear that the French stone was more popular. Examples of millstones made of this stone are widespread in North America and throughout the world,” Joseph Hannibal of The Cleveland Museum of Natural History told Science Daily. The French stone was considered to be superior for producing white flour.