Peridot is a gem-quality variety of olivine and is one of the few gemstones that comes in a single color. The depth of green depends on its level of iron content. Peridot's color can vary from yellow-green and olive to brownish green and looks best under natural daylight.
Its vivid green color does not change under artificial light. The best colored peridot has an iron percentage of less than 15% and typically includes some trace elements of nickel and chromium, which contribute to its color. A deep and intense green colored peridot is considered the most desirable and the most valuable.
Peridot occurs with excellent transparency. Eye-clean specimens are abundant. Larger stones may appear slightly cloudy owing to the presence of inclusions and impurities. When cut and polished, peridot has an attractive, greasy and vitreous luster.