[ too r-muh-lin, -leen ]
/ ˈtʊər mə lɪn, -ˌlin /


any of a group of silicate minerals of complex composition, containing boron, aluminum, etc., usually black but having various colored, transparent varieties used as gems.
Also tour·ma·lin [too r-muh-lin] /ˈtʊər mə lɪn/, turmaline.

Origin of tourmaline

1750–60; earlier tourmalin < German Turmalin, ultimately < Sinhalese tōramalliya carnelian; see -in2


tour·ma·lin·ic [too r-muh-lin-ik] /ˌtʊər məˈlɪn ɪk/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Examples from the Web for tourmaline

British Dictionary definitions for tourmaline

/ (ˈtʊəməˌliːn) /


any of a group of hard glassy minerals of variable colour consisting of complex borosilicates of aluminium with quantities of lithium, sodium, calcium, potassium, iron, and magnesium in hexagonal crystalline form: used in optical and electrical equipment and in jewellery

Derived forms of tourmaline

tourmalinic (ˌtʊəməˈlɪnɪk), adjective

Word Origin for tourmaline

C18: from German Turmalin, from Sinhalese toramalli carnelian
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

Scientific definitions for tourmaline

[ turmə-lĭn, -lēn′ ]

Any of several minerals having the general chemical formula (Na,Ca)(Mg,Fe,Al,Li)3Al6(BO3)3Si6O18(OH)4. Tourmaline occurs in many different translucent colors, usually in crystals shaped like 3-, 6-, or 9-sided prisms. It occurs in igneous and metamorphic rocks, especially in pegmatites.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.