… Siliceous fossil meals (for example, kieselguhr, tripolite and diatomite) and similar siliceous earths, whether or not calcined, of an …
Explanatory notes
… (for example, kieselguhr, tripolite and diatomite) and similar siliceous earths, whether or not calcined, of an apparent … with the true tripoli known as “rotten‑stone”, which, since it results from the natural decomposition of certain …