Peridot erupts out of volcanoes and is flung at us from outer space, how cool is that?
Peridot is the gem version of the mineral olivine. Peridot forms in upper mantle magmas between 20-55 miles deep and erupts in alkaline balsaltic magma flows most often as OITs (ocean island basalt) flows. Its a silicate mineral with a composition of (Mg, Fe)2SiO4
Peridot has been dug since as least 1500 B.C. for gem and ritual purposes by the Egyptians and other ancient cultures. Peridot has been mined at Zabargad an ancient island which was lost for several centuries because the island is tiny and can easily be lost in the fog. Mining only stopped in Zabargad about 80 years ago.
In the United States, most peridot comes from Arizona and is so prevalent that there is an entire town named for it and mined by the native peoples. Ants often bring the little gems to the surface.
Peridot is a 6.5-7 on the mohs scale of hardness making it a good choice for earrings and pendants and it is the birthstone of August.
A very rare form of peridot comes from nickel-iron meteorites called pallasite.