2510 | | Natural calcium phosphates, natural aluminum calcium phosphates and phosphatic chalk: | | | | |
2511 | | Natural barium sulfate (barytes); natural barium carbonate (witherite), whether or not calcined, other than barium oxide of heading 2816: | | | | |
2511.20.00 | 00 | Natural barium carbonate (witherite) | kg | Free | | 30% |
2512.00.00 | 00 | Siliceous fossil meals (for example, kieselguhr, tripolite and diatomite) and similar siliceous earths, whether or not calcined, of an apparent specific gravity of 1 or less | t | Free | | Free |
2515 | | Marble, travertine and other calcareous monumental or building stone of an apparent specific gravity of 2.5 or more, and alabaster, whether or not roughly trimmed or merely cut, by sawing or otherwise, into blocks or slabs of a rectangular (including square) shape: | | | | |
2515.20.00 | 00 | Other calcareous monumental or building stone; alabaster | t | 3% | Free (A,AU,BH,CA, CL,E,IL,J,JO,MA, MX,P,SG) | 50% |
2517 | | Pebbles, gravel, broken or crushed stone, of a kind commonly used for concrete aggregates, for road metalling, or for railway or other ballast; shingle and flint, whether or not heat-treated; macadam of slag, dross or similar industrial waste, whether or not incorporating the materials cited in the first part of the heading; tarred macadam; granules, chippings and powder, of stones of heading 2515 or 2516, whether or not heat-treated: | | | | |
2517.20.00 | 00 | Macadam of slag, dross or similar industrial waste, whether or not incorporating the materials cited in subheading 2517.10 | t | Free | | 30% |
2517.30.00 | 00 | Tarred macadam | t | Free | | 30% |
2518 | | Dolomite whether or not calcined or sintered, including dolomite roughly trimmed or merely cut, by sawing or otherwise, into blocks or slabs of a rectangular (including square) shape; dolomite ramming mix: | | | | |
2518.10.00 | 00 | Dolomite, not calcined or sintered | t | Free | | Free |
2518.20.00 | 00 | Calcined or sintered dolomite | t | 3% | Free (A,AU,BH,CA, CL,E,IL,J,JO,MA, MX,P,SG) | 30% |
2519 | | Natural magnesium carbonate (magnesite); fused magnesia; dead-burned (sintered) magnesia, whether or not containing small quantities of other oxides added before sintering; other magnesium oxide, whether or not pure: | | | | |
2519.10.00 | 00 | Natural magnesium carbonate (magnesite) | t | Free | | $10.33/t |
2519.90.20 | 00 | Caustic calcined magnesite | t | Free | | $20.70/t |
2520 | | Gypsum; anhydrite; plasters (consisting of calcined gypsum or calcium sulfate) whether or not colored, with or without small quantities of accelerators or retarders: | | | | |
2521.00.00 | 00 | Limestone flux; limestone and other calcareous stone, of a kind used for the manufacture of lime or cement | t | Free | | Free |
2522 | | Quicklime, slaked lime and hydraulic lime, other than calcium oxide and hydroxide of heading 2825: | | | | |
2525 | | Mica, including splittings; mica waste: | | | | |
2525.10.00 | | Crude mica and mica rifted into sheets or splittings | | Free | | Free |
2525.10.00 | 10 | Split block mica | kg | | | |
2525.10.00 | 20 | Mica splittings | kg | | | |
2525.20.00 | 00 | Mica powder | kg | Free | | 20% |
2525.30.00 | 00 | Mica waste | kg | Free | | 8.8¢/kg |
2528 | | Natural borates and concentrates thereof (calcined or not), but not including borates separated from natural brine; natural boric acid containing not more than 85 percent of H3BO3 calculated on the dry weight: | | | | |