• synonyms


or spi·nelle

[spi-nel, spin-l]
  1. any of a group of minerals composed principally of oxides of magnesium, aluminum, iron, manganese, chromium, etc., characterized by their hardness and octahedral crystals.
  2. a mineral of this group, essentially magnesium aluminate, MgAl2O4, some varieties being used as gems.
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Origin of spinel

1520–30; < French spinelle < Italian spinella, equivalent to spin(a) thorn (< Latin spīna) + -ella -elle
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for spinel

Historical Examples

  • The hardness of Spinel is 8, or about that of topaz, and the specific gravity 3.6.

    Birds and Nature, Vol. 12 No. 5 [December 1902]


  • A ring with a spinel ruby in it dropped out: she recognised the stone—it was Miss Minerva's ring.

    Heart and Science

    Wilkie Collins

  • The natives of India call the Spinel the pomegranate ruby and believe to this day that it possesses valuable medicinal properties.

  • The Spinel rubies differ from the true or corundum rubies in hardness, specific gravity and system of crystallization.

  • Spinel is singly refracting in polarized light and corundum doubly refracting.

British Dictionary definitions for spinel


  1. any of a group of hard glassy minerals of variable colour consisting of oxides of aluminium, magnesium, chromium, iron, zinc, or manganese and occurring in the form of octahedral crystals: used as gemstones
  2. a hard, glassy mineral composed of magnesium-aluminium oxide found in metamorphosed limestones and many basic and ultrabasic igneous rocks. Formula: MgAl 2 O 4
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Word Origin

C16: from French spinelle, from Italian spinella, diminutive of spina a thorn, from Latin; so called from the shape of the crystals
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

spinel in Science


  1. A hard, variously colored cubic mineral, having usually octahedral crystals and occurring in igneous and metamorphosed carbonate rocks. The red variety is valued as a gem and is sometimes confused with the ruby. Chemical formula: MgAl2O4.
  2. Any of a group of minerals that are oxides of magnesium, iron, zinc, manganese, or aluminum.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.