Emeralds

Emerald (Be 3 Al 2 (SiO 3 ) 6 ) is a gemstone of the mineral beryl. It has a green color caused by the presence of trace amounts of chromium and/or vanadium. It has a hardness of 7.5 – 8 on the Mohs hardness scale. Colombian emeralds are widely regarded as the best quality, and Colombia is the largest producer of emeralds in the world.