law: 16. Royalty.-
  (1) A lessee shall pay royalty to the Central Government in respect of any mineral removed or consumed by him from the area covered under the production lease, at the rate for the time being specified in the First Schedule in respect of that mineral.
  (2) The Central Government may, by notification in the Official Gazette, amend the First Schedule so as to enhance or reduce the rate at which royalty shall be payable in respect of any mineral with effect from such date as may be specified in the notification:
  Provided that the Central Government shall not enhance the rate of royalty in respect of any mineral more than once during any period of three years.