Crossword clue: a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite

The most common answer is terbium (7 letters).

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

Possible answers

terbium 7 letters wn-def

a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite