Coffee, sugar, and bananas are the leading commercial and export crops in Guatemala's mainly agricultural economy. There is some manufacturing, primarily of refined sugar, textiles and clothing for the U.S. market, furniture, and chemicals. Zinc and lead concentrates are mined. There are nickel and petroleum deposits in the north, and a petroleum industry has developed, although it has been limited by political unrest and environmentalist opposition. Extensive jade deposits are found in E central Guatemala. The Mayan town of Chichicastenango is a popular site for the nation's tourist industry. The leading imports include fuel, machinery, transportation equipment, construction materials, grain, fertilizers, and electricity. The United States, El Salvador, and Mexico are the major trading partners.