Slag-glazed stones are the most important diagnostic artifact for locating and identifying the small pit iron smelters of Ohio. Nothing like these stones can be found as the result of natural processes.
Instead, these stones indicate the presence of an pit iron smelter nearby. Those shown above were found in the bed of Hoover Reservoir just below the furnace mound. The shoe-shaped stone is 7 " long and 3.25" wide.