(1) For the past three years, Jesse Fisher and his colleagues have spent the summer months extracting the mineral fluorspar from what they believe is the only existing mine of its kind in Britain.(2) The Northern Pennine orefield has been an important source of lead, fluorspar (commercial fluorite), and other metallic and nonmetallic ores for many centuries.(3) Problems with the treatment of the fluorspar ores to remove silica evidently limited the success of the mine during this period.(4) The name fluorine comes from the mineral fluorspar , or calcium fluoride, in which it was found.(5) The mining of nonmetallic ores - fluorspar , witherite, and barytes (commercial barite ore) - in the northern Pennines began about the time lead and iron mining were in decline.
