1.1(6)Notwithstanding any other provision in this Act, a person who, before May 18, 1986, worked any deposit of sand, gravel, clay or soil for the purpose of using it for its chemical or special physical properties, or both, or for its contained minerals, shall not hereafter be required to pay any royalty or rent with respect to the sand, gravel, clay or soil taken from the deposit for those purposes.