'gray manganese ore' definitions:

Definition of 'gray manganese ore'

From: GCIDE
  • Manganite \Man"ga*nite\, n.
  • 1. (Min.) One of the oxides of manganese; -- called also gray manganese ore. It occurs in brilliant steel-gray or iron-black crystals, also massive. [1913 Webster]
  • 2. (Chem.) A compound of manganese dioxide with a metallic oxide; so called as though derived from the hypothetical manganous acid. [1913 Webster]