Peridot is the gemstone variety of the mineral olivine.
It's one of only a few minerals that occurs in just one colour. The exact shade can vary depending on the amount of iron that's present.
Peridot forms in Earth's upper mantle rather than in the crust. This section extends to a depth of about 255 miles.
In ancient texts peridot was known as 'topazos'. For many years it was mined on the island by the same name.
On the modern birthstone list peridot is the birthstone for August.
When used for crystal healing peridot is associated with growth, renewal and prosperity. It was once believed to possess protective powers against evil spirits and nightmares.