Peridot is the accepted birthstone for August. It is also the accepted anniversary gemstone for the 16th year of marriage. Peridot should be a lively lime green, without a brownish or olive cast. Peridot is the child of volcanic action. Tiny peridot crystals are sometimes combed from the black sands of Hawaii. Peridots were favored by pirates, considered powerful amulets against all evil, and when set in gold, were said to protect the wearer from the terrors of the night. They had medicinal uses, too. If fashioned into a chalice from which medicines were drunk, they intensified the effects of the drug. Care should be taken to protect peridot from scratches, sharp blows, household chemicals and extreme temperature changes. Do not use a home ultrasonic machine for cleaning. The peridot is abundant, and is available in larger sizes. It is found in Burma and the U.S. The most important source of peridot in the world is the San Carlos Apache Indian Reservation near Globe, Arizona, where it is mined by native Americans. Large sizes are mined in Myanmar (Burma) and peridot is also found in China.