… Siliceous fossil meals (for example, kieselguhr, tripolite and diatomite) and similar … or not calcined, of an apparent specific gravity of 1 or less. …
Explanatory notes
… 25.12 ‑ S iliceous fossil meals (for example, kieselguhr, tripolite and diatomite) and similar … or not calcined, of an apparent specific gravity of 1 or less. These materials are siliceous earths formed of small … siliceous earths are kieselguhr, tripolite, diatomite and moler earth. Although certain earths classified here are …