Definition of "spinel" []

• A hard, variously colored mineral with composition MgAl2O4, having usually octahedral crystals and occurring in igneous and carbonate rocks. The red variety is valued as a gem and is sometimes confused with ruby. (noun)
• Any of a group of minerals that are oxides of magnesium, iron, zinc, manganese, or aluminum. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Violet red spinel is sometimes called "_almandine spinel_.""
• "Nissan and NEC say their laminated cell batteries use a stable crystal structure called spinel manganese that will eliminate the risk of overheating."
• "The magnesium salt Mg (AlO_ {2}) _ {2} is called spinel, and many other of its salts, called aluminates, are found in nature."