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 > 2843 Colloidal precious metals; inorganic or organic compounds of precious metals, whether or not chemically defined; amalgams of precious metals > Colloidal precious metals