Olivine is also the mineral of the gemstone known as “peridot.” It is a yellow-green to green gemstone that is very popular in jewelry. Peridot serves as a birthstone for the month of August. The most valued colors are dark olive green and a bright lime green. These specimens are of the mineral forsterite because the iron-rich fayalite is usually a brownish, less desirable color.

Much of the world’s peridot used in mass-production jewelry is mined at the San Carlos Reservation in Arizona. There, a few basalt flows containing nodules of granular olivine are the source of the peridot. Most of the stones produced there are a few carats or less in size and often contain visible crystals of chromite or other minerals. They are cut in Asia and returned to the United States in commercial jewelry.

Higher quality and larger peridot crystals are mined in Pakistan and Myanmar. There, crystals of olivine are found in metamorphic rocks. These are usually found in association with serpentine or dolomitic marble.