Marbleized Proterozoic Stromatolites from Michigan

Description: This is a marbleized example of stromatolitic material from the Proterozoic of Radville, Michigan, a locality north of Iron Moutain. Marble is the result of either regional or contact metamorphism of limestone or dolostone, and typically results in the loss any fossils or sedimentary textures of the original rock. The pleasing green coloration is most likely due to serpentine, the result of a high magnesium limestone content.