( 1 ) THIS batch of writ petitions is filed seeking issuance of a Mandamus declaring the Note to Rule 12 (5) (e) and Rules 12 (5) (f) (i) and (f) (ii) of the Andhra Pradesh Minor Mineral Concession Rules, 1966, as ultra vires the Mines and 10 Minerals (Regulation and Development) Act, 1957 and the provisions in Part XIII of the Constitution of India.

( 2 ) THE petitioners are quarry lease-holders of black granite and coloured granite in the State of Andhra Pradesh. The order granting the lease stated that the grantee should abide by the Andhra Pradesh Minor Mineral Concession Rules, 1966 (hereinafter referred to as the Rules ).

( 3 ) THE petitioners aggrieved of the conditions envisaged in the impugned rules, namely, establishment of a granite cutting and polishing unit within the State itself, interfering with the free trade in granite even after its extraction, and imposing penal rate (double the rate) of seigniorage in regard to granite exported through harbours, other than in the State of Andhra Pradesh, resorted to these proceedings.

( 4 ) BEFORE dealing with the merits in detail, it is necessary to refer to some of the relevant provisions of the Central Ac