1.- Except where their context or Note 4 to this Chapter otherwise requires, the headings of this Chapter cover only products which are in the crude state or which have been washed (even with chemical substances eliminating the impurities without changing the structure of the product), crushed, ground, powdered, levigated, sifted, screened, concentrated by flotation, magnetic separation or other mechanical or physical processes (except crystallisation), but not products which have been roasted, calcined, obtained by mixing or subjected to processing beyond that mentioned in each heading.
The products of this Chapter may contain an added anti‑dusting agent, provided that such addition does not render the product particularly suitable for specific use rather than for general use.
2.‑ This Chapter does not cover :
(a) Sublimed sulphur, precipitated sulphur or colloidal sulphur (heading 28.02);
(b) Earth colours containing 70 % or more by weight of combined iron evaluated as Fe2O3 (heading 28.21);
(c) Medicaments or other products of Chapter 30;
(d) Perfumery, cosmetic or toilet preparations (Chapter 33);
(e) Setts, curbstones or flagstones (heading 68.01); mosaic cubes or the like (heading 68.02); roofing, facing or damp course slates (heading 68.03);
(f) Precious or semi‑precious stones (heading 71.02 or 71.03);
(g) Cultured crystals (other than optical elements) weighing not less than 2.5 g each, of sodium chloride or of magnesium oxide, of heading 38.24; optical elements of sodium chloride or of magnesium oxide (heading 90.01);
(h) Billiard chalks (heading 95.04); or
(ij) Writing or drawing chalks or tailors’ chalks (heading 96.09).
3.‑ Any products classifiable in heading 25.17 and any other heading of the Chapter are to be classified in heading 25.17.
4.‑ Heading 25.30 applies, inter alia, to : vermiculite, perlite and chlorites, unexpanded; earth colours, whether or not calcined or mixed together; natural micaceous iron oxides; meerschaum (whether or not in polished pieces); amber; agglomerated meerschaum and agglomerated amber, in plates, rods, sticks or similar forms, not worked after moulding; jet; strontianite (whether or not calcined), other than strontium oxide; broken pieces of pottery, brick or concrete.