2517 - Pebbles, gravel, broken or crushed stone, of a kind commonly used for concrete aggregates, for road metalling, or for railway or other ballast; shingle and flint, whether or not heat-treated; macadam of slag, dross or similar industrial waste, whether or not incorporating the materials cited in the first part of the heading; tarred macadam; granules, chippings and powder, of stones of heading 2515 or 2516, whether or not heat-treated:

Heading 2517 encompasses a range of natural mineral materials primarily used in construction and infrastructure development. This category includes various forms of stone that have been broken, crushed, or otherwise processed, specifically designated for applications such as concrete aggregates, road surfacing, and railway ballast. It also covers natural materials like shingle and flint, regardless of whether they have undergone heat treatment. A significant portion of this heading is dedicated to processed mineral waste, such as macadam derived from slag or similar industrial byproducts, which can be combined with other stones.

Distinguishing heading 2517 from its sibling categories within Chapter 25 (Salt, Sulfur, Earths, and Stone) is crucial. While Chapter 25 generally deals with raw minerals, heading 2517 focuses on specific types of stone and processed mineral waste characterized by their particle size, fragmentation, and intended bulk use in construction and civil engineering projects, rather than as raw building stone (like dimension stone classified elsewhere) or finer mineral powders for other industrial purposes. The emphasis here is on materials prepared for their aggregate or ballast properties.

Within heading 2517, further subdivisions (subheadings) differentiate based on the specific form and origin of the material. Subheading 2517.10 distinguishes between natural, fragmented stones and flint, while subheadings 2517.20 and 2517.30 delineate different types of macadam, specifically those derived from industrial waste and tarred macadam, respectively. The final, unnumbered category addresses granules, chippings, and powder derived from specific types of stone, further refining the classification based on particle size and source rock.