Section 06 Products of the chemical or allied 28 Inorganic chemicals; organic or inorganic compounds of precious metals, of rare earth metals, of radioactive elements or isotopes 28 05 Alkali or alkaline-earth metals; rare-earth metals, scandium and yttrium, whether or not intermixed or interalloyed; mercury 28 05 12 - - Calcium 28 05 12 00 - - Calcium Commodity Code Description 28 05 12 00 000 - - Calcium