Jiangsu boasts a network of rivers and lakes. The Yangtze River runs over 400 km through the province from west to east while the Beijing-Hangzhou Grand Canal runs 690 km from north to south. There is the Qinhuai River in its southwest; Northern Jiangsu General Irrigation Canal, Xinmu River and Nantong-Yanzhou Canal in the northern part. The province also boasts more than 290 lakes including the Taihu Lake and Hongze Lake. Jiangsu has a wide distribution of mineral resources with a rich variety. The mineral products discovered so far total 120. Major energy resources include coal, petroleum and natural gas. Non-metallic resources include sulphur, phosphorus, sodium salt, crystal, cyanite, sapphire, diamond, kaolin, limestone, quartz sand, marble and pottery clay. The metallic resources include copper, lead, zinc, silver, gold, strontium and manganese. The province is particularly rich in clay, building materials, chemical raw materials, metallurgic auxiliary materials, minerals for special uses and non-ferrous metals.