Chapter 28 — Inorganic chemicals; organic or inorganic compounds of precious metals, of rareearth metals,of radioactive elements or of isotopes

Heading 2805 — Alkali or alkalineearth metals; rareearth metals, scandium and yttrium, whether or not intermixed or interalloyed; mercury.

National subdivision 2805.1 — Alkali or alkalineearth metals:

Subheading 2805.12 — Calcium