The Redburn Mine was developed to recover fluorspar from a section of the Red Vein begining approximately one kilometer west of the village of Rookhope. The mine is one of the few in Weardale of completely modern origins. Data from surveys conducted by Sir Kingsley Dunham suggested the possibility of commercial-grade deposits along an unproven section of the Red Vein between Rookhope and the Groverake Mine. In 1964 the Weardale Lead Company drove an incline and reached a substantial vein of fluorite at the base of the Great Limestone. The mine was later taken over by SAMUK, and a mineralized section of the vein was worked for over 300 meters to the west. Levels on this section extended down to the Five Yard Limestone. A second mineralized section was discovered 1200 meters west of the first. This section was worked for an additional 610 meters from levels largely in the Great and Little Limestones. Extraction of fluorspar is reported to have been very thorough, and the mine was closed in 1981 when economic reserves were considered depleted (Source - Mindat)