The peridot is one of only two precious gems to form within the earth’s mantle rather than its crust. It is usually created in the upper mantle somewhere between 20-55 miles below the ground (diamonds, the other exception, form in the lower mantle at a depth of 100-150 miles). Peridot is brought to the surface naturally by way of volcanic activity, but can be mined through man-made methods.
Peridot was originally discovered and mined on a small Egyptian island called Topazios (now St. John’s Island or Zabargad). For years, people confused the stone with Topaz, thanks to its island of origin. It has also been mistaken for emeralds over the centuries. In fact, there is speculation that Cleopatra’s famous collection of emeralds may have actually been Peridot.