(b) The measure of damages in any civil action for the unauthorized extraction, severance, injury or removal of coal from land, including but not limited to, action for trespass or conversion, when the extraction, severance, injury or removal is in good faith shall be the fair market value of the coal in place before severance as of the time of extraction, severance, injury or removal. The fair market value of the coal in place shall be calculated as the royalty rate prevailing at the time and place of severance. The measure of damages in all other civil actions for the unauthorized extraction, severance, injury or removal of coal from land, including but not limited to, actions for trespass or conversion, shall be the fair market value of the coal after severance, at the time and place of severance, without allowance for labor and expenses.