Energy commodities include electricity, gas, coal and oil. It closed following privatisation of the coal mining industry. These mineral resources include billions of tons of lignite coal. Solar energy gets dinged for its dependence on mining coal and quartz. The borough expanded dramatically in population with the development of coal mining. Dagestan is rich in oil, natural gas, coal, and many other minerals. Petroleum-derived naphthalene is usually purer than that derived from coal tar. Denmark depends almost entirely on thermal power generated from coal, oil and gas. North Staffordshire was a centre for coal mining. Montan wax is a fossilized wax extracted from coal and lignite. Ash is formed in gasification from inorganic impurities in the coal. Propane combustion is much cleaner than that of coal or unleaded gasoline. He comes from a family of coal miners. Early steamships were fueled by wood, later ones by coal or fuel oil. There are no substantial deposits of iron, coal, or oil.