Brazil, Southern and central Africa, Madagascar, Color: yellow, Hardness: 7, Refractive index: 1.54 1.55, Density: 2.65 2.66, Chemical composition: SiO2, Crystal structure: hexagonal, Origins: Widespread; best stones come from Brazil. Citrine is one of the least expensive gemstones. Even very big pieces, 50 carats and more, can be easily found on the market. Greenish-yellow and orange stones are more valuable, and heat treatment is often applied to enhance the yellow color., Yellow, brown, Yellow, brown, Yellow, brown, Yellow, brown, Yellow, brown, Yellow, brown, Yellow, brown, Yellow, brown, Yellow, brown, Yellow, brown
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, Madagascar, Mozambique, Pakistan, Russia, India, Sri Lanka, 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.