APEX (I at., the extreme end of a thing; point, summit). A term used in mining to des ignate the outcropping edge of a mineral vein or lode. As interpreted legally, it is not necessary that the edge of the vein should project above the surface of the ground, but simply above the surface of the inclosing bedrock, and both vein and bedrock may therefore be covered by soil or drift. The term outcrop in the legal sense, as used above, does not agree with the geological application of the term in all cases; for if a vein dips nearly parallel with a sloping surface, and may be exposed at a point below the apex, due to an irregularity in its dip, this second ex posure, while constituting an outcrop in the geo logical sense, would not be one legally. Accord ing to the Revised Statutes of 1872, a miner hav ing the apex of a vein within the boundaries of his claim is allowed to follow it along the strike until it intersects the end lines of his claim ex tended vertically downward. On the dip, how
ever, he is at liberty to follow it indefinitely, even if it extends outside the vertical side lines of his surface location. This prohibits another person from sinking to the first party's vein from a point outside the latter's surface claim. This apex rule has led to many lawsuits, some of which were costly, involving property worth several million dollars. Thus, where two veins join below the surface and each is worked by a different party, both may endeavor to claim pos session of the true apex. but under the apex law slighter pretenses are sometimes used by one person to gain ownership of another's vein. See LQDE ; MINING CLAIMS; OUTCROP ; DIP: STRIKE: ORE DEPOSITS; and consult: Barringer and Adams. The of 11 hies and Mining in the Cnited States (Boston. 1807).