Azerbaijan is rich in natural resources which provide energy, especially in crude oil and natural gas, and hydroelectricity and wind power. Other natural resources include minerals such as gold, silver, iron, copper, titanium, chromium, manganese, cobalt, molybdenum, complex ore and antimony which are mined. Crude oil and natural gas, are the most important products of Azerbaijan's economy and the main sources of export contributing to its economic growth. They are also the basis for an widespread system of refineries, which produce gasoline, herbicides, fertilizers, kerosene, synthetic rubber, and plastics. The oil and natural gas are carried through pipelines from the Caspian Sea to the Black Sea ports of Novorossiysk in Russia and Suspa in Georgia and to the Mediterranean Sea port Ceyhan in Turkey. Hydroelectric power plants supply 20% of the country's electric capacity and wind power production is slowly increasing. Other major industries include cement, fertiliser, steel, chemicals, automobiles, and machinery.