Mendip Hills In some areas the limestone and the dolomitic conglomerate have been mineralised with lead and zinc ores. From the time of Roman Britain until 1908, the hills were an important source of lead. These areas were the centre of a major mining industry in the past and this is reflected in areas of contaminated rough ground known locally as "gruffy". The word "gruffy" is thought to derive from the grooves that were formed where the lead ore was extracted from veins near the surface. Other commodities obtained included calamine (zinc ore), manganese, iron, copper and baryte. The eastern area reaches
Ore Metal Exchange aims to add uranium to its list of metals on warrant. The World Bank reports that China was the top importer of ores and metals in 2005 followed by the US and Japan. DILL, H.G. (2010) "The “chessboard” classification scheme of mineral deposits: Mineralogy and geology from aluminum to zirconium," Earth-Science Reviews, Volume 100, Issue 1-4, June 2010, Pages 1-420 Ore An ore is an occurrence of rock or sediment that contains sufficient minerals with economically important elements, typically metals, that can be economically extracted from the deposit. The ores are extracted from the earth through mining; they