Siliceous Fossil Meals & Earths (Diatomite, Kieselguhr, Tripolite)

Classified under a single 10-digit line (2512000000), diatomite and related siliceous fossil meals are distinguished by their unusually low apparent specific gravity of 1 or less — a physical property that drives their use as filtration media, functional fillers, and mild abrasives across food processing, brewing, and industrial applications. Canada and Mexico are the leading US import sources, with Germany, Japan, and India also contributing meaningfully to supply. Importers should note that calcined versus flux-calcined grades carry different performance profiles and may affect classification decisions at the 10-digit level.