🌊 Aquamarine Optics Lab: Refractive Index 1.567-1.590 (typically 1.577-1.583), Dispersion and Brilliance of a Cut Aquamarine

Aquamarine (Be3Al2Si6O18 with Fe2+/Fe3+): refractive index 1.567-1.590 (typically 1.577-1.583), Mohs hardness 7.5-8, dispersion 0.014. Aquamarine is the pale blue to blue-green variety of beryl, the same mineral as emerald, coloured by iron instead of chromium. Crystals grow large and clean, and the stone has Mohs hardness 7.5 to 8 and a refractive index near 1.58.