Section 13
SEC. 13. This Act shall take effect upon its approval. However, the rates prescribed in Section 3 of this Act shall take effect as follows: On non-metallic minerals and quarry resources, fifty per centum of the rate prescribed therein until March 31, 1981, and thereafter the full rate shall be imposed. On all metallic minerals, fifty per centum of the rate prescribed therein until March 31, 1981, and thereafter the full rate shall be imposed. Approved, September 19, 1980.