225 ILCS 705/35.01

Every person engaged in mining coal for any corporation, company, firm or individual, shall be paid in lawful money of the United States or par check for all coal mined and loaded into the mine car by such person for such corporation, company, firm or individual, including lump, egg, nut, pea and slack, or such other grades as said coal may be divided into, at such price as may be agreed upon by the respective parties.