2509.00 - Chalk:

This HTS category, 2509.00, encompasses chalk in its various forms. Chalk, a soft, white, porous sedimentary rock, is primarily composed of the mineral calcite, which is a naturally occurring crystalline form of calcium carbonate (CaCO₃). It is often found in layers and is formed from the skeletal remains of marine plankton. This classification is distinct from its sibling categories within Chapter 25, which cover a wide range of raw mineral products such as salt, sulfur, earths, stone, plastering materials, lime, and cement. Unlike these other mineral products, chalk's specific composition and soft texture differentiate it.

The subcategories within 2509.00 differentiate based on the processing or form of the chalk. The primary subdivision is between "Crude" chalk and "Other" chalk. "Crude" typically refers to chalk in its raw, unworked state, as extracted from the ground. The "Other" category would then encompass chalk that has undergone some degree of processing, such as crushing, grinding, or shaping, but without significant alteration of its fundamental composition. This distinction is important for determining the appropriate tariff rate based on the degree of preparation for end-use.