225 ILCS 745/160

(a) Using or attempting to use an expired license is a Class A misdemeanor. (b) Each of the following acts is a Class A misdemeanor for the first offense and a Class 4 felony for a second or subsequent offense: (1) A violation of any provision of this Act or its rules, except as noted in subsection (a) of this Section. (2) The making of any willfully false oath or affirmation in any matter or proceeding where an oath or affirmation is required by this Act. (3) Using or attempting to use an inactive, suspended, or revoked license or the license or seal of another, or impersonating another licensee, or practicing geology as a Licensed Professional Geologist in Illinois while one's license is inactive, suspended, or revoked. (4) The practice, attempt to practice, or offer to practice professional geology in Illinois without a license as a Licensed Professional Geologist. Each day of practicing professional geology or attempting to practice professional geology, and each instance of offering to practice professional geology, without a license as a Licensed Professional Geologist constitutes a separate offense. (5) Advertising or displaying any sign or card or other device that might indicate to the public that the person or entity is entitled to practice as a Licensed Professional Geologist, unless that person holds an active license as a Licensed Professional Geologist in the State of Illinois. (6) Fraud, misrepresentation, or concealment in applying for or procuring a license under this Act, or in connection with applying for the renewal of a license under this Act. (7) The inability to practice with reasonable judgment, skill, or safety as a result of habitual or excessive use or addiction to alcohol, narcotics, stimulants, or any other chemical agent or drug. (8) Engaging in dishonorable, unethical, or unprofessional conduct of a nature likely to deceive, defraud, or harm the public. (9) A violation of any provision of this Act or any rules adopted under this Act.