((a)) ** General rule** In the case of the mines, wells, and other natural deposits listed in subsection (b), the allowance for depletion under section 611 shall be the percentage, specified in subsection (b), of the gross income from the property excluding from such gross income an amount equal to any rents or royalties paid or incurred by the taxpayer in respect of the property. Such allowance shall not exceed 50 percent (100 percent in the case of oil and gas properties) of the taxpayer’s taxable income from the property (computed without allowance for depletion and without any deduction under section 199A). For purposes of the preceding sentence, the allowable deductions taken into account with respect to expenses of mining in computing the taxable income from the property shall be decreased by an amount equal to so much of any gain which (1) is treated under section 1245 (relating to gain from disposition of certain depreciable property) as ordinary income, and (2) is properly allocable to the property. In no case shall the allowance for depletion under section 611 be less than it would be if computed without reference to this section.

((b)) ** Percentage depletion rates** The mines, wells, and other natural deposits, and the percentages, referred to in subsection (a) are as follows:

((1)) ** 22 percent**

((A)) sulphur and uranium; and

((B)) if from deposits in the United States—anorthosite, clay, laterite, and nephelite syenite (to the extent that alumina and aluminum compounds are extracted therefrom), asbestos, bauxite, celestite, chromite, corundum, fluorspar, graphite, ilmenite, kyanite, mica, olivine, quartz crystals (radio grade), rutile, block steatite talc, and zircon, and ores of the following metals: antimony, beryllium, bismuth, cadmium, cobalt, columbium, lead, lithium, manganese, mercury, molybdenum, nickel, platinum and platinum group metals, tantalum, thorium, tin, titanium, tungsten, vanadium, and zinc.

((2)) ** 15 percent** If from deposits in the United States—

((A)) gold, silver, copper, and iron ore, and

((B)) oil shale (except shale described in paragraph (5)).

((3)) ** 14 percent**

((A)) metal mines (if paragraph (1)(B) or (2)(A) does not apply), rock asphalt, and vermiculite; and

((B)) if paragraph (1)(B), (5), or (6)(B) does not apply, ball clay, bentonite, china clay, sagger clay, and clay used or sold for use for purposes dependent on its refractory properties.

((4)) ** 10 percent** Asbestos (if paragraph (1)(B) does not apply), brucite, coal, lignite, perlite, sodium chloride, and wollastonite.

((5)) ** 7½ percent** Clay and shale used or sold for use in the manufacture of sewer pipe or brick, and clay, shale, and slate used or sold for use as sintered or burned lightweight aggregates.

((6)) ** 5 percent**

((A)) gravel, peat, pumice, sand, scoria, shale (except shale described in paragraph (2)(B) or (5)), and stone (except stone described in paragraph (7));

((B)) clay used, or sold for use, in the manufacture of drainage and roofing tile, flower pots, and kindred products; and

((C)) if from brine wells—bromine, calcium chloride, and magnesium chloride.

((7)) ** 14 percent** All other minerals, including, but not limited to, aplite, barite, borax, calcium carbonates, diatomaceous earth, dolomite, feldspar, fullers earth, garnet, gilsonite, granite, limestone, magnesite, magnesium carbonates, marble, mollusk shells (including clam shells and oyster shells), phosphate rock, potash, quartzite, slate, soapstone, stone (used or sold for use by the mine owner or operator as dimension stone or ornamental stone), thenardite, tripoli, trona, and (if paragraph (1)(B) does not apply) bauxite, flake graphite, fluorspar, lepidolite, mica, spodumene, and talc (including pyrophyllite), except that, unless sold on bid in direct competition with a bona fide bid to sell a mineral listed in paragraph (3), the percentage shall be 5 percent for any such other mineral (other than slate to which paragraph (5) applies) when used, or sold for use, by the mine owner or operator as rip rap, ballast, road material, rubble, concrete aggregates, or for similar purposes. For purposes of this paragraph, the term “all other minerals” does not include—

((A)) soil, sod, dirt, turf, water, or mosses;

((B)) minerals from sea water, the air, or similar inexhaustible sources; or

((C)) oil and gas wells.

((c)) ** Definition of gross income from property** For purposes of this section—

((1)) ** Gross income from the property** The term “gross income from the property” means, in the case of a property other than an oil or gas well and other than a geothermal deposit, the gross income from mining.

((2)) ** Mining** The term “mining” includes not merely the extraction of the ores or minerals from the ground but also the treatment processes considered as mining described in paragraph (4) (and the treatment processes necessary or incidental thereto), and so much of the transportation of ores or minerals (whether or not by common carrier) from the point of extraction from the ground to the plants or mills in which such treatment processes are applied thereto as is not in excess of 50 miles unless the Secretary finds that the physical and other requirements are such that the ore or mineral must be transported a greater distance to such plants or mills.

((3)) ** Extraction of the ores or minerals from the ground** The term “extraction of the ores or minerals from the ground” includes the extraction by mine owners or operators of ores or minerals from the waste or residue of prior mining. The preceding sentence shall not apply to any such extraction of the mineral or ore by a purchaser of such waste or residue or of the rights to extract ores or minerals therefrom.

((4)) ** Treatment processes considered as mining** The following treatment processes where applied by the mine owner or operator shall be considered as mining to the extent they are applied to the ore or mineral in respect of which he is entitled to a deduction for depletion under section 611:

((A)) In the case of coal—cleaning, breaking, sizing, dust allaying, treating to prevent freezing, and loading for shipment;

((B)) in the case of sulfur recovered by the Frasch process—cleaning, pumping to vats, cooling, breaking, and loading for shipment;

((C)) in the case of iron ore, bauxite, ball and sagger clay, rock asphalt, and ores or minerals which are customarily sold in the form of a crude mineral product—sorting, concentrating, sintering, and substantially equivalent processes to bring to shipping grade and form, and loading for shipment;

((D)) in the case of lead, zinc, copper, gold, silver, uranium, or fluorspar ores, potash, and ores or minerals which are not customarily sold in the form of the crude mineral product—crushing, grinding, and beneficiation by concentration (gravity, flotation, amalgamation, electrostatic, or magnetic), cyanidation, leaching, crystallization, precipitation (but not including electrolytic deposition, roasting, thermal or electric smelting, or refining), or by substantially equivalent processes or combination of processes used in the separation or extraction of the product or products from the ore or the mineral or minerals from other material from the mine or other natural deposit;

((E)) the pulverization of talc, the burning of magnesite, the sintering and nodulizing of phosphate rock, the decarbonation of trona, and the furnacing of quicksilver ores;

((F)) in the case of calcium carbonates and other minerals when used in making cement—all processes (other than preheating of the kiln feed) applied prior to the introduction of the kiln feed into the kiln, but not including any subsequent process;

((G)) in the case of clay to which paragraph (5) or (6)(B) of subsection (b) applies—crushing, grinding, and separating the mineral from waste, but not including any subsequent process;

((H)) in the case of oil shale—extraction from the ground, crushing, loading into the retort, and retorting (including in situ retorting), but not hydrogenation, refining, or any other process subsequent to retorting; and

((I)) any other treatment process provided for by regulations prescribed by the Secretary which, with respect to the particular ore or mineral, is not inconsistent with the preceding provisions of this paragraph.

((5)) ** Treatment processes not considered as mining** Unless such processes are otherwise provided for in paragraph (4) (or are necessary or incidental to processes so provided for), the following treatment processes shall not be considered as “mining”: electrolytic deposition, roasting, calcining, thermal or electric smelting, refining, polishing, fine pulverization, blending with other materials, treatment effecting a chemical change, thermal action, and molding or shaping.

((d)) ** Denial of percentage depletion in case of oil and gas wells** Except as provided in section 613A, in the case of any oil or gas well, the allowance for depletion shall be computed without reference to this section.

((e)) ** Percentage depletion for geothermal deposits**

((1)) ** In general** In the case of geothermal deposits located in the United States or in a possession of the United States, for purposes of subsection (a)—

((A)) such deposits shall be treated as listed in subsection (b), and

((B)) 15 percent shall be deemed to be the percentage specified in subsection (b).

((2)) ** Geothermal deposit defined** For purposes of paragraph (1), the term “geothermal deposit” means a geothermal reservoir consisting of natural heat which is stored in rocks or in an aqueous liquid or vapor (whether or not under pressure). Such a deposit shall in no case be treated as a gas well for purposes of this section or section 613A, and this section shall not apply to a geothermal deposit which is located outside the United States or its possessions.

((3)) ** Percentage depletion not to include lease bonuses, etc.** In the case of any geothermal deposit, the term “gross income from the property” shall, for purposes of this section, not include any amount described in section 613A(d)(5).