philippium

Century Dictionary and Cyclopedia

1. n. A supposed new chemical element announced by Delafontaine as present in the mineral samars-kite. Its existence has not been confirmed; what was supposed to be its oxid has been shown to be a mixture, probably, for the most part, of terbia and yttria.

Wiktionary

1. n. chemistry, obsolete A supposed metallic element obtainable from samarskite, later discovered to be a mixture of yttrium and terbium.

GNU Webster's 1913

1. n. (Chem.) A rare and doubtful metallic element said to have been discovered in the mineral samarskite.