APEX RULE

apex rule.Mining law. The principle that a vein of ore may be mined if it extends beyond the

vertical  boundaries  of  the  surface  claim  on  which  the  vein  apexes.  —  Also  termed  extralateral

right. Cf. INTRALIMINAL RIGHT. [Cases: Mines and Minerals    30. C.J.S. Mines and Minerals

§ 69.] [Blacks Law 8th]