This is a Thumbnail Size Green Emerald from Gutu, Masvingo, Zimbabwe
Dimensions: 2cm (0.7”) x 1cm (0.3”)
Weight: 2.6 grams = 13 carats
Emerald is a gemstone and a variety of the mineral beryl colored green by trace amounts of chromium or sometimes vanadium
Chemical formula: Be₃Al₂SiO₆
