Mining and prospecting are controlled primarily by the Mining Act of 1926, by its amendments, and by regulations made thereunder. Special acts apply to coal (Coal Mines Act of 1925, and amendments), petroleum (1937), radioactive minerals (Atomic Energy Act of 1945), bauxite (1959), and iron and steel (1959), and to quarries (1944) which comprise all surface workings with faces over 15 ft high, including opencast coal workings. The detailed privileges and obligations regarding prospecting and mining are complex, and depend upon the ownership and form of title of the land, and, if separate, of the minerals.
Most Crown land, most Maori land so declared, and certain alienated Crown and Maori lands are open for prospecting, which may be carried out by the holder of a miner's right, which has particular significance in the case of gold; a prospecting warrant which covers specified lands; a prospecting licence which gives the exclusive right to prospect over marked land of up to 1,000 acres; a tunnel prospecting licence; or a mineral prospecting warrant, which gives the exclusive right to prospect for the specified mineral(s) over an area of up to 10,000 acres. All warrants and licences require vigorous and continuous prospecting to be undertaken, and the reporting to the Inspector of Mines of all mineral discoveries. Provided these conditions are fulfilled, they also give priority in obtaining new prospecting licences or warrants over the same area, and mining privileges over a specified smaller portion of it. In addition, any land is available for prospecting with the consent of the owner or occupier. The Minister of Mines has the sole right to prospect for ironsands and bauxite, but can authorise others to do so.
All precious metals belong to the Crown. Any holder of a miner's right may apply for a claim licence, in an existing or newly proclaimed mining district, in which he is entitled to sole occupancy for mining and to any gold it may contain. Mineral licences may be granted by the Mining Warden for the mining of the specified mineral(s), other than gold, on Crown and certain related lands. Rent and royalties are payable. Depending on the nature of the mineral reservation, licences to work minerals on privately owned land can be obtained under the Mining Act. All workings, however, must conform to the legal requirements of the Mining Act and its regulations, and of the Inspector of Mines or Quarries.