Codex entry·Ores
Zirconium node
Entries
- Entry 1
The principal ore of zirconium is zircon, ZrSiO₄, usually recovered from heavy-mineral sands alongside ilmenite and rutile. Natural zircon contains hafnium with zirconium at roughly a 1-to-50 ratio.
- Entry 2
Zirconium alloys are valuable in nuclear reactors because they resist corrosion while absorbing very few neutrons. Hafnium behaves chemically almost the same but absorbs neutrons strongly, so reactor-grade zirconium must be purified.
- Entry 3
Zircon crystals are exceptionally durable geological clocks. Grains from Western Australia's Jack Hills have been dated to about 4.4 billion years old, making them the oldest known terrestrial material.