Harmonized System
Section V > Chapter 25 > Heading 2506
Quartz (other than natural sands); quartzite, whether or not roughly trimmed or merely cut, by sawing or otherwise, into blocks or slabs of a rectangular (including square) shape.
Section V > Chapter 25 > Heading 2507
Kaolin and other kaolinic clays, whether or not calcined.
Section V > Chapter 25 > Heading 2507 > 2507.00
Kaolin and other kaolinic clays, whether or not calcined
Section V > Chapter 25 > Heading 2508
Other clays (not including expanded clays of heading 68.06), andalusite, kyanite and sillimanite, whether or not calcined; mullite; chamotte or dinas earths.
Section V > Chapter 25 > Heading 2508 > 2508.40
Other clays
Section V > Chapter 25 > Heading 2508 > 2508.50
Andalusite, kyanite and sillimanite