The Blackdene Mine is located just north of the River Wear, between the villages of St. John's Chapel and Ireshopeburn. Lead mining on many of numerous veins in this area dates back to at least the early 15th century. The Blackdene Mine proper was originally developed by the Beaumont Company in the early 19th century for lead. The main workings follow the Blackdene Vein northeastward from near the banks of the River Wear, and eventually intersected those of the Elmsford Mine which worked a nearby section of the Slitt Vein.
Fluorspar was mined from both the Blackdene and Slitt Veins during the early 20th century, but the mine appears to have been abandoned when acquired by United Steel in 1949. Extensive exploration and development in the Blackdene occurred during the 1950's at levels between the Three Yard Limestone to below the Scar Limestone. By 1973 commercial reserves on the Blackdene Vein appeared exhausted, and a new incline was driven to access unmined portions of the Slitt Vein. With nationalization of the steel industry, ownership of the mine passed to British Steel, but it was disposed of when the industry crashed in 1982. Weardale Mining and Processing continued to operate the mine until 1987 when it was finally closed. Most of the mine is now inaccessable due to flooding and what is still accessible is badly understoped. (Source - Mindat)