In mineralogy, spinel classifies a whole group of realted minerals, only a dew are of gemstone quality, and are the ones Roosik & Co selected for this jewels. The coloring agents are iron, chromium, vanadium and cobalt. Large stones are rare.
Color: Violet, purple, red, orange
Moh's hardness: 8
Chemical composition:MgAl2O4 Mangesium aluminium oxide