Emerald Precious StoneHardness:7.5 - 8.0. Occurrence: Colombia, Brazil, Zimbabwe (Rhodesia), South Africa, Ural mountains (Russia), Zambia, India, Tanzania, Pakistan, Australia, U.S. (Connecticut, Maine, North Carolina), Austria and NorwayAppearance: Emerald refers to the green variety of beryl. There are however, gem quality green beryls which are not emeralds. All emeralds contain inclusions, which are evidence as to the genuineness of the stone. The name is derived from the Greek word Smaragdos, meaning Enhancements: Emerald is usually treated with colorless oil, wax, or natural and synthetic resins into voids to improve appearance. Surface cavities of emerald is commonly filled with a hardened colorless substance. Emerald is also occasionally dyed with dye or colored oil.