Sub-Chapter20052006
Salt (including table salt)$17,129$14,471
Natural sands of all kinds$375 
Other clays (not including expanded clays of heading 68.06), andalusite, ky ...$1,140$736
Chalk.$1,131$3,259
Pebbles, gravel, broken or crushed stone $352
Gypsum; anhydrite; plasters$714$2,450
Limestone flux; limestone$7 
Quicklime, slaked lime and hydraulic lime$45 
Portland cement, aluminous cement, slag cement$766,127$851,344
Natural steatite, whether or not roughly trimmed$726$771
Mineral substances$1,111$1,167
Total$788,505$874,550