Linked from
The 47 pages that link to Rare-earth element, each with the reason it gives.
PhosphorRelated: Rare-earth ions such as europium and terbium are common phosphor activators.
FluoriteRelated: Trace rare-earth ions can contribute to fluorite’s color and luminescence.
Fiber laserRelated: Rare-earth ions such as ytterbium and erbium provide the gain.
Phosphate mineralRelated: Monazite and other phosphates can serve as sources of rare-earth elements.
AllaniteRelated: These elements occupy major cation sites in allanite’s structure.