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.
jade refers to an ornamental mineral, often known for its green types, though appears naturally in other colors as well, especially yellow and white. jade can refer to either of two different silicate minerals: nephrite, or jadeite.
agate is a common stone formation, consisting of chalcedony and quartz as its main components, consisting of a wide variety of colors. agates are primarily formed within volcanic and metamorphic stones.