spə̇ˈnel sometimes ˈspin ə l noun
or spi·nelle spə̇ˈnel
( -s )
Etymology: Italian spinella, spinello, diminutive of spina thorn, from Latin; from the pointed crystals — more at spine
1.
a. : a mineral MgAl 2 O 4 consisting of an oxide of magnesium and aluminum that is noted for its great hardness, that usually forms octahedral crystals varying in color (as from colorless to ruby-red to black), and that is used as a gemstone — see almandine , balas , ceylonite , rubicelle , spinel ruby
b. : a synthetic substance similar to the mineral spinel that is used as a gemstone, as bearings for watches and various instruments, and as a refractory
2.
a. : a member of the spinel series
b. : a member of the spinel group
3. : a substance (as a sulfide) that has a similar formula and the same crystal structure as a spinel