Peridot, as an untouched gemstone, is notable for its striking olive-green color, which can range from yellowish-green to a darker, brownish-green depending on the iron content. This gem is part of the olivine mineral group and is distinguished by its glassy luster and transparency. Peridot is often found in volcanic areas, where it crystallizes from magma. It's one of the few gemstones that occur in only one color, though the intensity of green can vary. This natural variation adds to its unique charm, making it a prized stone in jewelry-making for its natural, unaltered beauty.