SECTION VI - PRODUCTS OF THE CHEMICAL OR ALLIED INDUSTRIES > CHAPTER 28 - INORGANIC CHEMICALS; ORGANIC OR INORGANIC COMPOUNDS OF PRECIOUS METALS, OF RARE-EARTH METALS, OF RADIOACTIVE ELEMENTS OR OF ISOTOPES > VI. MISCELLANEOUS > 2850 00 Hydrides, nitrides, azides, silicides and borides, whether or not chemically defined, other than compounds which are also carbides of heading 2849 > Borides