Kenya, Southern and central Africa
Brazil, Madagascar, Mozambique, Pakistan, Russia, India, Sri Lanka, China, Color: blue to greenish blue, Hardness: 7.5, Refractive index: 1.57 1.59, Density: 2.67 2.75, Chemical composition: Be3Al2(SiO3)6, Crystal structure: hexagonal, Origins: Brazil, Nigeria, China. Aquamarine is a light blue or light greenish-blue variety of beryl, with darker stones being more expensive. Heat enhancement is often applied to enhance the blue color of aquamarines, but only clean pieces can be heated.
(Al,Mg) 8(Al,Si) 6O 20Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Be3Al2SiO6