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tourmaline

American  
[toor-muh-lin, -leen] / ˈtʊər mə lɪn, -ˌlin /
Also tourmalin

noun

  1. 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.


tourmaline British  
/ ˌtʊəməˈlɪnɪk, ˈtʊəməˌliːn /

noun

  1. 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

"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

tourmaline Scientific  
/ trmə-lĭn,-lēn′ /
  1. Any of several minerals having the general chemical formula (Na,Ca)(Mg,Fe,Al,Li) 3 Al 6 (BO 3 ) 3 Si 6 O 18 (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.


Usage

What does tourmaline mean? Tourmaline is a mineral that is commonly black but also has transparent, colored varieties considered gemstones, including in pink and green.Tourmaline varies in composition and is typically categorized into three types: iron tourmaline (a black variety, also called schorl), magnesium tourmaline (a brown variety, also called dravite), and alkali tourmaline.As a gemstone, tourmaline is classified as semiprecious, a label given to gemstones that are not as valuable as those considered precious. Tourmaline is generally inexpensive due to its abundance, but certain varieties are more expensive, such as those from Paraiba, Brazil, which are valued for their color saturation.Tourmaline is one of the birthstones for the month of October. It is associated with the zodiac signs Libra and Scorpio. It is also the gem designated for an eighth wedding anniversary.Tourmaline has the ability to become electrically charged when heated and is also used in electrical equipment.Tourmaline can also be spelled tourmalin and turmaline.Example: Many people mistake the red tourmaline stone in my ring for a ruby.

Other Word Forms

  • tourmalinic adjective

Etymology

Origin of tourmaline

1750–60; earlier tourmalin < German Turmalin, ultimately < Sinhalese tōramalliya “carnelian”; -in 2

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Like obsidian, in fact, their edges are sharp but the shards have an almost twirly shape and lack the crystalline structure of black-colored minerals like augite or tourmaline.

From Salon

Then we each get a piece of black tourmaline, considered a so-called “grounding stone” that is said to offer protection.

From Los Angeles Times

The crown glitters with stones including tourmalines, white and yellow topazes, rubies, amethysts, sapphires, garnet, peridot, zircons, spinel and aquamarines.

From Seattle Times

It’s set with rubies, amethysts, sapphires, garnet, topazes and tourmalines.

From Seattle Times

Weighing five pounds, with a velvet cap and band of ermine fur, the crown includes a dazzling array of rubies, amethysts, sapphires, topazes, tourmalines and garnet.

From Salon