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Sapphire starry

Sapphire starry

    The studed sapphires are a beautiful curiosity of the Nature. Blues, pink or blacks, they expose under a direct light source an effect of asterism. A six-point star oscillating on the surface of the stone. This visual effect is due to needles of shine on which the light is reflected and comes to create this étoile d' asterism

    To know more about the mineralogy of the studed black sapphire, see Mindat.org->

    Gemological data

    • Chemical formula : Al2 O3
    • Hardness (Mohs) : 9
    • Density : 4
    • Refractive index : ne=1.759-1.761 no=1.767-1.770
    • Birefingence : 0.008-0.009
    • Crystal system : Rhombohedral - Trigonal
    • Group : Corundum

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