2508.40.01.10 - Common blue clay and other ball clays

This HTS category, 2508.40.01.10, specifically enumerates "common blue clay and other ball clays." Ball clays are fine-grained, plastic clays that are typically white or gray when fired, and are distinguished by their high plasticity and bonding strength. "Common blue clay" refers to a specific type of ball clay known for its characteristic blue-grey color before firing, often associated with its mineral composition and geological origin. These clays are primarily utilized in industries requiring high-quality ceramic materials, such as the manufacturing of sanitaryware, tiles, and electrical porcelain, as well as in foundry molds due to their excellent plasticity and firing properties.

It is important to differentiate this classification from its sibling categories within 2508.40.01. Category 2508.40.01.20 covers "decolorizing earths and fuller's earth," which are clays primarily valued for their adsorptive properties, used for filtering and purifying oils and other liquids. Category 2508.40.01.50 encompasses "other" clays within this broader group, serving as a residual category for clays not fitting the specific descriptions of ball clays or decolorizing earths. Therefore, 2508.40.01.10 is exclusively for ball clays and their common blue variant, focusing on their physical plasticity and ceramic utility rather than absorptive capabilities.

As this classification is a leaf node, there are no further subcategories. The classification of common blue clay and other ball clays under 2508.40.01.10 is definitive and does not involve further subdivision within the HTS. Classification decisions should therefore hinge on the inherent properties of the clay, specifically its plasticity, particle size, and suitability for ceramic applications, confirming it aligns with the established characteristics of ball clay.