More than 60 kinds of minerals are found in Qinghai. Deposits of lake salt, sylvites, magnesites, lithium, iodine, natural sulphur, bromine, limestone for the chemical industries, quartzite and asbestos are the largest in the country. Potassium reserves account for 97 per cent of the country's total. The province has abundant reserves of oil and natural gas at the Qaidam Basin. Qinghai Oil Field is one of the four largest natural gas fields in China. The province has about 19 million kilowatts of electric power resources.