2529.21.00.00 - Containing by weight 97 percent or less of calcium fluoride

This HTS classification, 2529.21.00.00, covers fluorspar that contains by weight 97 percent or less of calcium fluoride (CaF₂). Fluorspar, also known as fluorite, is a mineral primarily composed of calcium fluoride. In this specific category, the mineral has a significant presence of other elements or impurities, reducing the calcium fluoride content to 97% or below. This material is typically found in crystalline or granular form and finds applications in various industrial processes, including the production of steel, aluminum, and certain chemicals.

The crucial distinguishing factor for this category lies in its precise calcium fluoride content. It is differentiated from its sibling category, 2529.22.00.00, which exclusively covers fluorspar containing more than 97 percent of calcium fluoride by weight. Therefore, the analytical determination of the calcium fluoride percentage is paramount for correct classification, with the threshold of 97% being the dividing line.

As this HTS code represents a leaf node, there are no further subcategories beneath it. Classification decisions under this heading will therefore depend entirely on the accurate assessment of the material's composition, specifically its calcium fluoride content, and its conformity to the description provided within Chapter 25 of the Harmonized Tariff Schedule.