Spinel – spinel group

colourless, yellow, brown, blue, pink, red, violet, orange, green, black

Transparent, Translucent, Opaque

red/pink: red - blue: inert - deep purple: red - pale blue and violet: green

red/pink: red

inclusion: spinel octahedrons, boehmite tubes, apatite, octahedral negative crystals, healing cracks, absorption spectrum: red and pink spinels: "organ pipes" (not in synthetic spinels) in the red; blue, green, violet spinels: Fe bands (not in synthetic spinels)! =>SPECTRUM

7,5 - 8

MgAI₂O₄

Cubic

1