The chemical composition of peridot is (Mg, Fe)2SiO4, with Mg in greater quantities than Fe. The origin of the name “peridot” is uncertain.

Peridot is occurs only in one color – an olive green. The intensity and the shade of the green depends on the amount of iron contained in the crystal structure. The color of individual peridot gem can vary from yellow, to olive green, to brownish-green. The most valued color is a dark olive-green.

Peridot olivine is the birthstone for the month of August. It is sometimes mistaken for other green colored gems. Olivine to which peridot belongs is a common mineral in mafic rocks and ulramafic rocks.

It is often found in lavas. But gem quality peridot forms a small fraction of these. Peridot can be also found in meteorites. Olivine in general is a very abundant mineral, but gem quality peridot is precioius and rare

Peridot olivine is mined in Egypt, Arizona, North Carolina, Hawaii, Nevada, New Mexico, Australia, Brazil, China, Kenya, Mexico, Myanmar, Norway, Pakistan, Saudi Arabia, South Africa, Sri Lanka and Tanzania.

High quality peridot weighing 13, 000 carats was recovered from anthills in Wyoming. Peridot crystals have been collected from some Pallasite meteorites. The largest cut peridot olivine is a 310 carat (62 g) specimen in the Smithsonian Museum in Washington, D.C.