… Other clays (not including expanded clays of heading 68.06), andalusite, kyanite and sillimanite, whether or not calcined; mullite; chamotte or dinas earths. …
Explanatory notes
… whether or not calcined; mullite; chamotte or dinas earths (+). 2508.10 ‑ Bentonite 2508.30 ‑ Fire‑clay 2508.40 … ceramic industry (bricks, building tiles, porcelain, china, earthenware, refractory bricks and other refractory goods, …