Meaning of cummingtonite

cum•ming•ton•ite

Pronunciation: (kum'ing-tu-nīt"), [key]
— n.
  1. an amphibole mineral, magnesium-iron silicate, similar in composition to anthophyllite but richer in iron.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.