spinel

or spi·nelle

[spi-nel, spin-l]

noun

any of a group of minerals composed principally of oxides of magnesium, aluminum, iron, manganese, chromium, etc., characterized by their hardness and octahedral crystals.
a mineral of this group, essentially magnesium aluminate, MgAl2O4, some varieties being used as gems.

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 of spinel

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]
Various
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.
Birds and Nature, Vol. 12 No. 5 [December 1902]
Various
The Spinel rubies differ from the true or corundum rubies in hardness, specific gravity and system of crystallization.
Birds and Nature, Vol. 12 No. 5 [December 1902]
Various
Spinel is singly refracting in polarized light and corundum doubly refracting.
Birds and Nature, Vol. 12 No. 5 [December 1902]
Various

British Dictionary definitions for spinel

spinel

noun

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
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

Word Origin for spinel

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

spinel

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.
Any of a group of minerals that are oxides of magnesium, iron, zinc, manganese, or aluminum.