Red, Pink, Bluish Violet To Greenish Blue, Purple, Lavender, Blue, Bluish-Green, Brown, Black, Colorless, Green, Orange, Yellow
Flame Spinel, Rubicelle, Ceylonite, Pleonaste
refractive index, SR nature, magnification and spectrum. An accurate RI reading can distinguish natural from synthetic spinel, which usually has a higher RI. Red spinel often shows a chromium spectrum with lines in the red, possibly as emission lines.
Spinel frequently occurs in an octahedral form with triangular etch pits on the faces. Also appears in a flat twinned form as a macle. Flame spinel or rubicelle: orange, orange-red to yellowish red spinel usually from Brazilceylonite: dingy blue, gray to black with no iron contentpleonaste: opaque very dark blue or green to black containing iron. Misnomers: Balas ruby, spinel ruby, almandine spinel, sapphire spinel, sapphirine. Blue and red spinel tends to be on the higher side of the RI limit.