- Color: green
- Hardness: 7.5 - 8
- Refractive index: 1.57 - 1.59
- Density: 2.67 - 2.75
- Chemical composition: Be3Al2(SiO3)6
- Crystal structure: hexagonal
- Lustre: vitreous
- Origins: Colombia, Zambia, Brazil, Madagascar, South Africa, Zimbabwe, Russia, India, Pakistan, Australia, USA, Pakistan.
Unlike other beryl varieties clean pieces of emerald are extremely rare end expensive. Emeralds are usually treated by polymers or colorless oil in order to hide microfissures and to improve their appearance. Emerald prices depend highly on the stone's color and clarity, and for this reason it is rather difficult to carry out an online valuation of them. We recommend referring to the Gemval.com online appraisal as a value approximation with a 15-20% maximum possible error.