Qu'est-ce qu'un spinel?
Qu'est-ce qu'un spinel?
- A hard, variously colored mineral with composition MgAl2O4, having usually octahedral crystals, occurring in igneous and metamorphosed carbonate rocks, and valued as a gem. The red variety is sometimes confused with ruby.
- Any of a group of minerals that are oxides of magnesium, iron, zinc, manganese, or aluminum.