Webster’s Revised Unabridged Dictionary · 1913
Polyhalite
Pol′y·ha′lite (pŏl′ĭ·hā′līt), n. [Poly- + Gr. ἅλς salt.] (Min.) A mineral usually occurring in fibrous masses, of a brick-red color, being tinged with iron, and consisting chiefly of the sulphates of lime, magnesia, and soda.