Peridot is an ancient Gem of the mineral Olivine.

The peridot gemstone is known for its greenish-yellow coloring and ranges from a solid green to green with hints of brown or yellow. 

The term peridot refers to green, gem-quality olivine. Forsterite is the magnesium (Mg)-dominant end, while fayalite is the iron (Fe)-dominant end. As idiochromatic gems, peridots get their characteristic green color from iron, an essential element of their chemical structure.