[too r-muh-lin, -leen]


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
Related formstour·ma·lin·ic [too r-muh-lin-ik] /ˌtʊər məˈlɪn ɪk/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for tourmaline

Historical Examples of tourmaline

  • The "Tourmaline's" men appeared highly delighted at our defeat.

    In Eastern Seas

    J. J. Smith

  • This plate of tourmaline can be turned round by the observer.

    The Story of the Heavens

    Robert Stawell Ball

  • I can't resist this tourmaline, and have carried it off with me.

  • Rutile is much lighter, 4·2, and the streak light-brown; tourmaline is only 3·2.

    Getting Gold

    J. C. F. Johnson

  • Of these minerals, beryl, garnet and tourmaline are the most abundant.

British Dictionary definitions for tourmaline



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 Formstourmalinic (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

Word Origin and History for tourmaline

complete silicate of aluminum and boron, 1759, ultimately from Sinhalese toramalli, a general name for cornelian.

Online Etymology Dictionary, © 2010 Douglas Harper

Science 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.