Kaolin and Other Kaolinic Clays (Including Calcined)

Kaolin and kaolinic clays — whether raw or calcined to alter their physical and chemical properties — are widely traded industrial minerals serving the paper coating, ceramics, paint, rubber, and plastics industries. A single 10-digit line (2507000000) covers all forms under this heading, with the calcined/uncalcined distinction noted in the heading description but not creating separate US tariff lines. The United Kingdom and Brazil are the leading US import sources, with New Zealand, the Netherlands, and China also supplying this market. Calcination significantly increases brightness and alters particle size, making the processing state commercially important even where it does not change the tariff line.