| Peridot | |
|---|---|
| |
| |
| General | |
| Category | Mineral |
| Formula | (Mg, Fe)2SiO4 |
| Identification | |
| Colour | Yellow to yellow-green |
| System | Orthorhombic |
| Cleavage | Poor |
| Fracture | Conchoidal |
| Hardness | 6.5-7 |
| Lustre | Vitreous |
| RI | 1.64-1.70 (DR +0.036) |
| Streak | White |
| SG | 3.2-4.3 |
Peridot (pronounced "pear-uh-dot" or "pear-uh-doe", IPA: /pɛɹɪdɑːt/ or Fr. /peʁido/) is the gem quality variety of forsterite olivine. The chemical composition of peridot is (Mg, Fe)2SiO4. The name of the gemstone is believed to come from either the Arabic word faridat meaning "gem" or the French word peritot meaning "unclear." Peridot is one of the few gemstones that comes in only one color. The depth of green depends on how much iron is contained in the crystal structure, and varies from yellow-green to olive to brownish green. Peridot is also often referred to as "poor man's emerald". Olivine is a very abundant mineral, but gem-quality peridot is rather rare. Peridot crystals have been collected from iron-nickel meteorites.
Occurrence
Peridot is found in Arizona, Hawaii, Nevada, and New Mexico, in the US, and in Australia, Brazil, China, Kenya, Mexico, Myanmar (Burma), Norway, Pakistan, South Africa, Sri Lanka, and Tanzania. Peridot of high quality is commercially mined in the eastern lava fields of Saudi Arabia. The largest cut peridot is a 310 carat (62 g) specimen in the Smithsonian Museum in Washington, D.C.. A special variety of a peridot from Pakistan is known as "Kashmir" peridot. Due to the large size of the rough stones found there, cutters have successfully created faceted stones of over 100 carats (20 g) from the rough gems of this area. Who gives a blood?
History and Lore
It is the birthstone for the month of August. According to folklore, the peridot will bring its wearer success, peace, and good luck. Peridot has been found in Egyptian jewellery from the early second millennium BCE and was mined from the volcanic island of Zebirget, or St. Johns Island, in the Red Sea. Native Hawaiians referred to peridot crystals as the tears of Pele, their goddess of fire.
External links
References
- Saudi Aramco World "Volcanic Arabia" by Peter Harrigan. March/April 2006. Peridot mining in Saudi Arabia.
- 1995-2002 Amethyst Galleries, Inc. "OLIVINE (Magnesium Iron Silicate)" Retrieved July 13, 2006.
- Hall, Cally, Gemstones (Smithsonian Handbooks), (1994, 2002) p113. NYU Press, ISBN 0-7894-8985-6
- 1998-2006 Bernardine Fine Art Jewelery "August Birthstone - Peridot" Retrieved July 14, 2006.