'Magnesite' definitions:

Definition of 'magnesite'

(from WordNet)
noun
A white mineral consisting of magnesium carbonate; a source of magnesium

Definition of 'Magnesite'

From: GCIDE
  • Magnesite \Mag"ne*site\, n. [Cf. F. magn['e]site.] (Min.) Native magnesium carbonate occurring in white compact or granular masses, and also in rhombohedral crystals. [1913 Webster]