2529 - Feldspar; leucite, nepheline and nepheline syenite; fluorspar:

Category 2529 encompasses naturally occurring mineral substances primarily composed of feldspar, leucite, nepheline, nepheline syenite, and fluorspar. These materials are generally classified as earths and stones, falling within Section V of the Harmonized Tariff Schedule, which deals with mineral products. Their classification here is based on their geological origin and primary mineral composition, rather than refined or manufactured states.

Distinguishing this category from its siblings, such as live animals (Chapter 01) or other mineral products like salt or sulfur (Chapter 25), is crucial for accurate tariff application. Category 2529 specifically focuses on these particular silicate minerals and fluorspar, excluding other distinct mineral commodities or raw materials. The key differentiator lies in the specific chemical and geological properties that define feldspar, leucite, nepheline, nepheline syenite, and fluorspar.

Within Category 2529, further subdivisions differentiate between feldspar (2529.10.00.00) and leucite, nepheline, and nepheline syenite (2529.30.00). While all are silicate minerals, these subcategories reflect distinct mineralogical compositions and potential end-uses, such as in ceramics, glass manufacturing, or as fluxes. Fluorspar is also a distinct component within this heading, recognized for its primary use in metallurgy, chemical production, and as a flux.