World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0000045162
Reproduction Date:

Title: Peridot  
Author: World Heritage Encyclopedia
Language: English
Subject: Birthstone, Topaz, Jewellery, Gemstones of Pakistan, Olivine
Collection: Gemstones, Silicate Minerals
Publisher: World Heritage Encyclopedia


Category Mineral
(repeating unit)
(Mg, Fe)2SiO4
Color Yellow, to yellow-green, olive-green, to brownish, sometimes a lime-green, to emerald-ish hue
Crystal system Orthorhombic
Cleavage Poor
Fracture Conchoidal
Mohs scale hardness 6.5–7
Luster Vitreous (glassy)
Streak None
Specific gravity 3.2–4.3
Refractive index 1.64–1.70
Birefringence +0.036

Peridot ( or ) is gem-quality olivine. Olivine is a silicate mineral with formula of (Mg, Fe)2SiO4. As peridot is the magnesium-rich variety (forsterite) the formula approaches Mg2SiO4.


  • Etymology 1
  • Appearance 2
  • Occurrence 3
    • Geologically 3.1
    • In meteorites 3.2
  • Gemology 4
  • Gallery 5
  • References 6
  • External links 7


The origin of the name peridot is uncertain. The Oxford English Dictionary suggests an alteration of AngloNorman pedoretés (classical Latin pæderot-), a kind of opal, rather than the Arabic word faridat, meaning "gem".

The Middle English Dictionary's entry on peridot includes several variations : peridod, peritot, pelidod and pilidod – other variants substitute y for the i's seen here. [1]

The earliest use in England is in the register of the St Albans Abbey, in Latin, and its translation in 1705 is possibly the first use of "peridot" in English. It records that on his death in 1245 Bishop John bequeathed various items to the Abbey: "He gave also three noble Rings, in one whereof is an Oriental Sapphire, of wonderful bigness: In another is the Stone call'd Peridot, in the middle whereof is set a Sapphire of great beauty; it is said to be good against the Cramp, and is made almost in the form of a Buckler: in the third Ring is also an Oriental Sapphire, but less than the former."[2]


Peridot is one of the few gemstones that occur in only one color, an olive green. The intensity and tint of the green, however, depends on how much iron is contained in the crystal structure, so the color of individual peridot gems can vary from yellow--to olive--to brownish-green. The most valued color is a dark olive-green.



Olivine, of which peridot is a type, is a common mineral in mafic and ultramafic rocks, and it is often found in lavas and in peridotite xenoliths of the mantle, which lavas carry to the surface; but gem quality peridot only occurs in a fraction of these settings. Peridot can be also found in meteorites.

Olivine in general is a very abundant mineral, but gem quality peridot is rather rare. This is due to the mineral's chemical instability on the Earth's surface. Olivine is usually found as small grains, and tends to exist in a heavily weathered state, unsuitable for decorative use. Large crystals of forsterite, the variety most often used to cut peridot gems, are rare; as a result olivine is considered to be precious.

Peridot olivine is mined in Arkansas, Arizona on the San Carlos Reservation, Hawaii, Nevada, and New Mexico at Kilbourne Hole, in the US; and in Australia, Brazil, China, Egypt, Kenya, Mexico, Myanmar (Burma), Norway, Pakistan, Saudi Arabia, South Africa, Sri Lanka, and Tanzania.

In meteorites

Peridot crystals have been collected from some Pallasite meteorites. A famous Pallasite was offered for auction in April 2008 with a requested price of close to $3 million at Bonhams, but remained unsold.[3]


It is sometimes mistaken for

  • USGS peridot data
  • Emporia Edu
  • Florida State University – Peridot

External links

  1. ^ Middle English Dictionary Ed Kuhn Part 3
  2. ^ The antiquities and history of Ireland By Sir James Ware, 1705: Cotton Library Folio 88 b, Nero D VII
  3. ^ Fukang Meteorite auction at Bonhams
  4. ^ Kunz, Gems and Precious Stones, on Peridot
  5. ^ "August Birthstone". American Gem Society. Retrieved June 28, 2013. 




Peridot olivine is the birthstone for the month of August.[5]

The largest cut peridot olivine is a 310 carat (62 g) specimen in the Smithsonian Museum in Washington, D.C.

, Germany. Cologne of Dom" treasure in the Three Magi, notably the "treasures church and peridots in many emeralds discussed the confusion between [4]

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.