yellow emitting fluorescent lamp phosphor compositions comprise cerium and manganese activated alkali - earth fluoroapatite compositions containing sodium having the approximate formula . sub . t ce . sub . v na . sub . w mn . sub . x . sub . y f z wherein s is from 0 to 1 t is from about 3 . 43 to about 4 . 01 v is about 0 . 3 w is about 0 . 3 x is from about 0 . 3 to about 0 . 4 y is about 3 . 00 z is from about 1 . 0 to about 4 . 0 . an improved two step firing process for producing the disclosed phosphors is described and an improved fluorescent lamp employing the disclosed phosphors is also described .