*MINING LAW OF 1872 AS AMENDED

Uncommon varieties of salable type minerals may be locatable provided that the deposits meet certain tests created by various judicial and administrative decisions. Federal mineral examiners determine uncommon varieties on a case-by-case basis.

Since 1963, petrified wood has not been locatable under the mining laws. Hobbyists may remove small amounts for noncommercial use free of charge. The Federal Government may sell larger amounts of petrified wood under applicable regulations (see 43 CFR 3620).

Since 1920, the Federal Government has leased fuels and certain other minerals (see 43 CFR 3000-3590). Leasable minerals today include oil and gas, oil shale, geothermal resources, potash, sodium, native asphalt, solid and semisolid bitumen, bituminous rock, phosphate, and coal. In Louisiana and New Mexico, sulphur is leasable.

Discovery of a Valuable Mineral Deposit

Federal statutes do not describe what constitutes a valuable mineral deposit. However, the Government adopted an "economic" definition of locatable minerals that has resulted in a test that makes use of the concept of an economic ore body. Consequently, several judicial and administrative decisions have established the "prudent man rule" of discovery, a Land Decision of the Department of the Interior in 1894, Castle v.Womble, 19 LD 455 (1894), states: "...where minerals have been found and the evidence is of such a character that a person of ordinary prudence would be justified in the further expenditure of his labor and means, with a reasonable prospect of success in developing a valuable mine, the requirements of the statutes have been met."