[ ak-tin-l-ahyt, ak-tuh-nl- ]
/ ækˈtɪn lˌaɪt, ˈæk tə nl- /

noun Mineralogy.

a variety of amphibole, occurring in greenish bladed crystals or in masses.

Origin of actinolite

First recorded in 1825–35; actino- + -lite

Related forms

ac·tin·o·lit·ic [ak-tin-l-it-ik, ak-tuh-nl-] /ækˌtɪn lˈɪt ɪk, ˌæk tə nl-/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for actinolite

British Dictionary definitions for actinolite


/ (ækˈtɪnəˌlaɪt) /


a green mineral of the amphibole group consisting of calcium magnesium iron silicate. Formula: Ca 2 (Mg,Fe) 5 Si 8 O 22 (OH) 2

Word Origin for actinolite

C19: from actino- (from the radiating crystals in some forms) + -lite
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for actinolite


[ ăk-tĭnə-līt′ ]

A greenish variety of amphibole. Actinolite is a monoclinic mineral, and occurs in long, slender, green needlelike crystals, or in fibrous, radiated forms in metamorphic rocks. Chemical formula: Ca2(Mg,Fe)5Si8O22OH2.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.