Peridot is formed of magnesium iron silicate – it only occurs in an olive-green colour. The intensity of the green depends on the amount iron, so the colour of different peridot gems can vary from yellow to brownish-green, with the most valuable colour being dark olive-green.
Most peridot is mined in Arizona, although in the past it was found in Hawaii. However, peridot has also been found on meteorites, then turned into jewellery – cosmic jewellery!
Peridot is softer than many other gemstones, so it should be stored carefully to avoid damage.