Barite 'tiff' and lead: one of Missouri's oldest mining districts

Washington County sits in one of Missouri’s oldest mining districts. Long before the Old Lead Belt to the north, the area around Potosi — tied to the early French colonial settlement of Mine au Breton — was worked for lead in the colonial and territorial era. Later, the county became known for barite, a heavy white mineral locally called ‘tiff,’ mined from surface pits and used in products from paint to drilling mud. That two-layer mining history, early lead and then long-running barite, shaped where towns grew and how families made a living for generations. For someone trying to understand the county, this is the central thread. Treat specific ‘firsts’ and dates as claims to confirm: the State Historical Society of Missouri and the Missouri Geological Survey within DNR are the right places to check the lead-and-tiff story rather than assuming the popular version.