Peridot is an unusual green-gold stone. The ancients loved it - it's found in ancient Egyptian jewellery as well as in Roman jewellery.
Scientists have been a bit puzzled as to how it is formed - it's mainly found in lava deposits, so comes from deep inside the earth. Some peridot has been found in meteorites. Most modern deposits are found in Pakistan, but Peridot from Arizona turns up in Native American jewellery particularly Apache jewelry with stones from mines in Arizona that have been worked for centuries..
Peridots are supposed to protect against negative feelings and they make for a lovely and unique birthstone for those born in August.