Spinel
Spinel is the magnesium–aluminum member of the larger spinel group of minerals with chemical formula MgAl₂O₄. Spinel is actually a large group of minerals. Gahnite, hercynite, ceylonite, picotite, and galaxite are all part of the spinel group. This oxide mineral is a Cubic crystal system with 7.5–8.0 hardness according to the Mohs hardness scale. Spinels […]