Site Contents

Blue Gemstones

 


Gemstone Crystal System Density Hardness Refractive index Treatments
lapisAgate microcrystalline 2.66 6.5-7.0 1.544-1.553 dying
aquamarineAquamarine hexagonal 2.72 7.5-8.0 1.577-1.583 heat

apaiteApatite

hexagonal 3.2 5 1.63-1.64 heat
azuriteAzurite monoclinic 3.7-3.8 3.5-4.0 1.730-1.838 none
benitoiteBenitoite hexagonal 3.64 6.0-6.5 1.757-1.804 none
chrysocollaChrysocolla microcrystalline 2.00-2.24 2-4 1.54 none
sapphireCorundum trigonal 4.00 9.0 1.762-1.770 heat
diamondDiamond cubic 3.52 10 2.417 radiation, drilling, fracture filling
lapisLapis Lazuli various 2.75 5.50 1.500 none
moonstoneMoonstone monoclinic 2.56 6.0-6.5 1.518-1.526 none
sapphireSapphire hexagonal 4.00 9 1.762-1.770 heat, fracture filling
spinelSpinel cubic 3.60 8 1.718 none
tanzaniteTanzanite orthorhombic 3.30 6.0-7.0 1.690-1.700 heat
topazTopaz orthorhombic 3.53 8.0 1.619-1.627 blue is irradiated
tourmalineTourmaline trigonal 3.06 7.0-7.5 1.624-1.644 heat
turquoiseTurquoise triclinic 2.73 5.0-6.0 1.610-1.650 dying, sealing
zirconZircon tetragonal 4.00 6.50 1.810-1.815 none