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Webster 1913 Edition

Noun.

[Gr.

πλάγιοσ

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.

plagionite

(mineralogy) A monoclinic-prismatic mineral containing antimony, lead, and sulfur.

plagionite Barthelmy, David (accessed 29 August 2016) Webmineral Mineralogy Database