Emerald

Emerald, the chemical formula Be3 (Al, Cr) 2Si6O18 (beryllium aluminosilicate), is a hexagonal mineral. Emerald is the best known and most valuable variety of the mineral beryl. The most famous and valuable - thanks to its unmistakable deep green color - are the emeralds from Colombia. Other important sites include Brazil, Zambia, Namibia and Russia. Green color Prismatic crystal appearance Six-system system Hardness 7.5 - 8 Glassy, matt gloss Fission is imperfect White scratch Density 2.6 - 2.8 g⋅cm − 3 Solubility in HF