phosphorite

A sedimentary rock consisting predominantly of apatite and other phosphates.

A name applied originally to a massive variety of apatite, but now used to embrace the more or less impure earthy to compact calcium phosphate which forms beds of considerable magnitude in some localities (Estremadura in Spain, Bohemia, etc.), and is of much economic importance.

A massive variety of apatite.

a sedimentary rock rich in phosphate minerals such as apatite