masrium

Century Dictionary and Cyclopedia

1. n. The name given to a supposed new chemical element of the same family with barium, strontium, and calcium, occurring as sulphate in the mineral masrite from Egypt. There has been no confirmation of its existence. The place to which the approximate atomic weight reported would assign it in the periodic classification of the elements seems to belong to the more recently discovered radium.

Wiktionary

1. n. chemistry, obsolete A rejected name for indium.