royal mines

Gold and silver mines owned by the king at common law as within his prerogative, although on private property. At common law, mines of gold and silver were by the prerogative of the sovereign, the property of the crown, though discovered in the land of private owners. They were termed "royal mines," and belonged to the sovereign wherever they were found. The prerogative is supposed to have originated as a necessary incident of the king's right of coinage in order to supply him with materials; metals in which there was no gold or silver, however, belonged to the proprietor of the soil. 36 Am J1st Min & M § 6.