| 2507.00.00 | 00 | Kaolin and other kaolinic clays, whether or not calcined | t | Free | | $2.46/t |
| 2508 | | Other clays (not including expanded clays of heading 6806), andalusite, kyanite and sillimanite, whether or not calcined; mullite; chamotte or dinas earths: | | | | |
| 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: | | | | |
| 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 |
| 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% |
| 2519.90.20 | 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: | | | | |
| 2522 | | Quicklime, slaked lime and hydraulic lime, other than calcium oxide and hydroxide of heading 2825: | | | | |
| 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: | | | | |
| 2528.10.00 | 00 | Natural sodium borates and concentrates thereof (whether or not calcined) | kg | Free | | Free |
| 2528.90.00 | 10 | Natural calcium borates | kg | | | |
| 2529.21.00 | 00 | Containing by weight 97 percent or less of calcium fluoride | t | Free | | 13.5% |
| 2529.22.00 | 00 | Containing by weight more than 97 percent of calcium fluoride | t | Free | | $5.51/t |
| 2606.00.00 | 30 | Bauxite, calcined: | | | | |
| 2713.11.00 | 00 | Not calcined | t | Free | | Free |
| 2713.12.00 | 00 | Calcined | t | Free | | 45% |
| 2805.12.00 | 00 | Calcium | kg | 3% | Free (A+,AU,BH, CA,CL,D,E,IL,J, JO,MA,MX, P,SG) | 25% |
| 2827.20.00 | 00 | Calcium chloride | kg | Free | | Free |
| 2827.59.25 | 00 | Of ammonium, of calcium or of zinc | kg | Free | | 25% |
| 2827.60.10 | 00 | Of calcium or of copper | kg | Free | | 25% |
| 2828 | | Hypochlorites; commercial calcium hypochlorite; chlorites; hypobromites: | | | | |
| 2828.10.00 | 00 | Commercial calcium hypochlorite and other calcium hypochlorites | kg | 2.4% | Free (A,AU,BH, CA,CL,E,IL,J,JO, MA,MX,P,SG) | 25% |
