psilomelane Meaning, Definition & Usage

  1. noun a mineral consisting of hydrated basic oxide of manganese and barium; a source of manganese

WordNet

Psi*lom"e*lane noun
Etymology
Gr. bare + , , black.
Definitions
  1. (Min.) A hydrous oxide of manganese, occurring in smooth, botryoidal forms, and massive, and having an iron-black or steel-gray color.

Webster 1913