'Wollastonite' definitions:

Definition of 'wollastonite'

(from WordNet)
noun
A white or greyish mineral typically found in metamorphic limestone; a silicate of calcium

Definition of 'Wollastonite'

From: GCIDE
  • Wollastonite \Wol"las*ton*ite\, n. [After Dr. W. H. Wollaston, an English chemist, who died in 1828.] (Min.) A silicate of lime of a white to gray, red, or yellow color, occurring generally in cleavable masses, rarely in tabular crystals; tabular spar. [1913 Webster]