Natural magnesium carbonate (magnesite); fused magnesia; dead-burned (sintered) magnesia, whether or not containing small quantities of other oxides added before sintering; other magnesium oxide, whether or not pure

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 (including by chemical substances to eliminate 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. 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 2802); (b) earth colours containing 70% or more by weight of combined iron evaluated as Fe2O3 (heading 2821); (c) medicaments or other products of Chapter 30; (d) perfumery, cosmetic or toilet preparations (Chapter 33); (e) setts, curbstones or flagstones (heading 6801); mosaic cubes or the like (heading 6802); roofing, facing or damp-course slates (heading 6803); (f) precious or semi-precious stones (heading 7102 or 7103); (g) cultured crystals (other than optical elements) weighing not less than 2.5 g each, of sodium chloride or of magnesium oxide, of heading 3824; optical elements of sodium chloride or of magnesium oxide (heading 9001). 3. Any reference in heading 2517 to 'dolomite' includes 'sintered or calcined dolomite' (including tarred dolomite). 4. Heading 2530 applies, inter alia, to vermiculite, perlite and chlorites, unexpanded; earth colours, whether or not calcined or mixed together; natural micaceous iron oxides; meerschaum; 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, concrete or brick.