emerald is a gemstone and a type of the mineral beryl colored green by trace amounts of chromium and sometimes vanadium. emerald in antiquity were mined in Egypt at locations on Mount Smaragdus since 1500 BCE.
peridot is gem-quality olivine and a silicate mineral. its green color is affiliate on the iron contents within the structure of the gem. the molecular structure of peridot consist of isomorphic olivine, silicate, magnesium and iron in an orthorhombic crystal system.