Source: Burma (Myanmar), Egypt, Norway, Pakistan, Saudi Arabia, Sri Lanka, USA (Arizona) (Hawaii)
Birthstone: August
The name "Peridot," (Péridot French, Peridoto Spanish or Italian) or "Chrysolite" (golden yellow peridot), means "golden stone" in Greek and is also derived from the French word "Peritot", meaning "unclear" due to significant amounts of inclusions in the stone. Peridot was treasured by the Egyptian Pharos. Some of Cleopatra's emeralds were actually peridots. In the Middle Ages, people wore peridot to gain foresight and divine inspiration as well as to protect them against evil.
Peridot Mining
Peridot mining dates back some 4,000 years. Ancient olivine peridot mineral deposits located on Saint Johns Island off the coast of Egypt in the Red Sea were documented by the greek historian Pliny the Elder (below, left) in his book Naturalis Historia (Natural History) in AD 70. Those ancient deposits on Saint Johns Island, now named Zabargad Island (below, right) still produce high-quality peridot stones, although most modern Peridot comes from the United States in Arizona. One of the largest faceted peridot gems in the world (Smithsonian Institution collection) is a 311.8 carat stone found on Zabargad.
Peridot was called "Topazion" until the 18th century when the British renamed it Peridot. A unique peridot specimen is mines in Pakistan and is called "Kashmir Peridot".
Peridot Composition
Peridot has a hardness of 6 1/2 to 7 on the Mohs scale. The Toughness of Peridot is Fair to Good. Peridot crystallizes in the orthorhombic crystal system, with a "granular mass" crystal habit, usually resulting in rounded pebbles. Peridot has a Vitreous luster. Peridot has a refractive index of 1.654.
Peridot, also called precious olivine (magnesium iron silicate), is a transparent green variant of forsteritic olivine associated with igneous rock. Peridot is classified as a Nesosilicate in the Silicate mineral group. Gem-quality olivine is a mineral that composes a lot of the earth's mantel, the layer below the outer crust. It is also common in basalts on the moon.
Peridot is a gemstone variety of forsterite, the magnesium-rich end of the olivine series. Chrysolite is a golden yellow variety of peridot. Peridot is ideochromatic, getting its distinct green coloration from ferrous iron which is a natural part of its crystal lattice structure. Higher quality peridot generally contain about 10 to 15% iron.
Transparent green olivine peridot (right) and a Peridotite druzy encrustation embedded in a basalt matrix commonly found in lava fields. Transparent olivine is usually found in arid climates such as Arizona, Egypt (Zabargad), Saudi Arabia and Pakistan (Suppatt district) due to its susceptibility to decay when subjected to weathering and rain.
Chemical composition: [Mg,Fe]2SiO4
