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Semi Precious Stone Spinel

Spinel is one of the groups of minerals that crystallize in the isometric system with an octahedral habit, and whose chemical compositions are also analogous. These minerals are combinations of bivalent and trivalent oxides of magnesium, zinc, iron, manganese, aluminum and also chromium, the general formula being represented as R''O•R'''2O3. The bivalent oxides may be MgO, ZnO, FeO and MnO, and the trivalent oxides may be Al2O3, Fe2O3, Mn2O3 and Cr2O3.

Historical Facts of Spinel

Refractive Index: 1.712 - 1.762

Chemical Composition: MgAl2O4

Hardness: 8

Crystal habit: Cubic, Octahedral

Crystal system: Isometric

Density: 3.54 - 3.63

Luster: Vitreous

Occurrence: Sri Lanka, Burma, Thailand, Australia, Kenya, Brazil

Types of spinel: Gahnite, Franklinite, Ringwoodite, Magnetite, Ulvöspinel, Hercynite, Jacobsite, Trevorite, Chromite

Color: Orange, Pink, Black, Blue, Lavender, Mauve, Greenish blue, Vivid Red

Gem Jewelry Spinel