'Plagionite' definitions:

Definition of 'Plagionite'

From: GCIDE

Plagionite \Pla"gi*o*nite\, n. [Gr. pla`gios oblique. So called in allusion to its usually oblique crystallization.] (Min.) A sulphide of lead and antimony, of a blackish lead-gray color and metallic luster. [1913 Webster]