Explanatory notes
… ), and wurzite (also a natural zinc sulphide) ( heading 25.30 ). (3) Cadmium sulphide (CdS). The artificial … excludes natural cadmium sulphide (greenockite) ( heading 25.30 ). (4) Ammonium hydrogen sulphide (ammonium … or copper (bornite, chalcopyrite) fall in headings 25.30 and 26.03 , respectively. (7) Strontium sulphide …