Definition of "hornblende" [horn•blende]

• A green to black amphibolic mineral, CaNa(Mg,Fe)4(Al,Fe,Ti)3Si6O22(OH,F)2, formed in the late stages of cooling in igneous rock. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "This stone is a volcanic rock called hornblende, of very fine grain, with minute specks of mica."
• "An examination of the stones which fell at Fort de France showed them to be of a variety of lava called hornblende and andesite."
• "The remaining rocks from here are richer in lime and iron, and show a series of gradual transitions from micacious granite, through grano-diorite to quartz diorite, with considerable quantities of dark mica, and green hornblende."