Green gem is a term used to describe a variety of precious stones that are green in color. The most common green gems are PERIDOT, JADE, BERYL, EMERALD, prase, and jadeite. PERIDOT is a yellow-green gemstone that is composed of magnesium iron silicate. JADE is a green gemstone that is composed of two minerals, nephrite and jadeite. BERYL is a mineral composed of beryllium aluminum cyclosilicate and is found in a variety of colors, including green. EMERALD is a green gemstone composed of beryllium aluminum silicate. Prase is a green gemstone composed of quartz and feldspar. Jadeite is a green gemstone composed of sodium aluminum silicate.