MINERAL RESOURCES Minerals of Illinois.—Somewhat more than a thousand min erals make up the rocks of the world, about one hundred forming the larger part of the common rocks. Ninety-one of these min erals have been found in larger or smaller amounts in the solid rocks and glacial drift of Illinois. Specimens of nearly all of these Illinois minerals are displayed in the State Museum at Springfield. About a dozen of these minerals are found in the rocks of Illinois in commercial quantities and constitute the valuable mineral resources of the state. The value of these minerals produced in 1917 ranged from $162,000,000 for coal to $5,900 for silver, with a total value of $238,000,000.
Importance of mineral resources.—Illinois ranks third among the states in the value of annual mineral production. The following table is based on mineral values for 1915: Thus Illinois produces about 5 per cent of the total mineral values of the United States. The value of the mineral products of Illinois in 1915 was three times the value of the total silver production of the United States; it exceeded the gold output of the United States, including Alaska, by $14,000,000; it was greater than the total value of the mineral products of 21 states having the smaller output of minerals. Minerals are the most valuable of the primary resources of Illinois except the products of the soil.
The foregoing table (II) of the mineral products of Illinois for 1915 shows the variety, amount, and value of the minerals of the state. The table for 1917 shows, in comparison with 1915, the influence of war activities on production and value of important minerals.
Coal.—The first discovery of coal in the United States was made in Illinois near Ottawa, La Salle County, by Father Hennepin, one of the early explorers, in 1679. Coal was first mined in Tllinois for commercial purposes in 1510 along the bluffs of the Big Muddy River in Jackson County. This first shipment of Illinois coal was made on a flatboat on the Big Muddy and Mississippi rivers to New Orleans. In 1532 several boat loads
were shipped to the same market. In 1533. 6,000 tons of coal were mined in St. Clair County and carried by wagons to St. Louis. The coal industry of St. Clair County induced the building of the first railroad in Illinois and the first west of the Allegheny Mountains. The cars were drawn by animal power. The Cool Report of the State Department of Mines and Minerals gives complete data concerning the coal industry of the state. In 1564 the annual output was 1.000,000 tons: in 1571 it had reached 3.000,000 tons. This amount was doubled in nine year with a production of 6.000.000 tons in 155'0. The output was again doubled in the short space of three years with 12.000,000 tons in 1553. In seven years more the annual production was again doubled with 25.000,000 tons in 1900. During the next eleven years the doubling process was again accomplished with an output of 50,000,000 tons in 1911. In the seven years following 1911 the increase has been SO per cent, with a production of 90.000.000 tons in 1915. So marked was the influence of war demands on the output of Illinois coal that the production for the year ending June 30. 1917. was 24 per cent greater than that of the previous year. and the production for the year ending June 30, 1915. was 11 per cent greater than for 1917. an increase of 55 per cent over the output of 1910. and 31 times the output of 1900.
Illinois ranks third among the coal-producing states. Pennsylvania ranks first with a production of 46 per cent of the total. followed by \Vest Virginia with 14 per cent. Illinois with 11 per cent. and Ohio with 4 per cent of the total.
Two-thirds of Illinois is underlain by beds or "veins" or "seams" of bituminous coal. The coal area of the state lies south of an east-west line joining Rock Island and Joliet, and is connected with the coal fields of southwestern Indiana and western Kentucky.