Peridot

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Art Nouveau Pendant Set with Peridot.
Image courtesy of Lang Antiques

The golden green gemstone peridot is the gem variety of the mineral forsterite. Long valued for its exceptional color, peridot has been used in jewelry since antiquity.


From the mid 1800s, peridot was a favored stone in jewelry, reaching the height of its popularity during the aesthetic period of the Victorian era and the reign of Edward VII of England, who designated it as his favorite gemstone[1]. Almost every school of the day - the Pre-Raphaelites, the Arts and Crafts movement, Art Nouveau as well as those working in the Edwardian style - incorporated this gemstone into their designs.


As a compliment to King Edward VII, whose favourite stone they were, there was a fashion for translucent green peridots for necklaces and pendants usually set round with diamonds...[2]

Generally peridot is classified as being a member of the olivine group, but it is actually a member of the isomorphous forsterite-fayalite group. A magnesium-iron silicate, finer quality stones contains a much higher proportion of magnesium to iron. Peridot is a type II gemstone on the GIA clarity scale with distinctive disc like gas inclusions called "lily pads". Another notable characteristic is its strong double refraction.


A prominent ancient source of peridot was St. John's Island, Egypt (also known as Topazios, Zabargad and Zebirget). Originally peridot was referred to as topazios by the ancient Greeks, hence the early name for this peridot rich region - Topazios. Historically, peridot has also been misnamed chrysolite (a yellowish-green variety of olivine) and olivine. The main commercial source for this gemstone is currently Arizona, USA with higher quality specimens mined from the more traditional sources of Myanmar, Pakistan and Egypt. The rarest source of gem quality peridot must be the stony-iron meteorites called pallasites.[3].


Peridot is the gift for the 16th anniversary and the birthstone for the month of August.


Unusual Victorian Brooch Featuring a 17.0 Carat Peridot Cameo with Diamond Surround.
Image courtesy of Lang Antiques
Gemological information for peridot
Color Green, yellow-green
Crystal Structure Orthorhombic
Refractive Index 1.654-1.690
Durability Sensitive to heat
Hardness 6.5-7
Treatments None known
Similar stones Peridot might be confused with many transparent green stones and glass, usually the strong double refraction is a good indicator
Peridot care
Ultrasonic cleaning Not safe
Steam cleaning Not safe
Warm soapy water Safe
Chemical attack Avoid
Light sensitivity Stable
Heat sensitivity May fracture

Notes

  1. Romero, 120
  2. Scarisbrick p.144.
  3. Gems & Gemology, 43

Sources consulted

  • Amstel-Bos, E.G.G van. Sieraden uit de negentiende eeuw. Lochem, The Netherlands: De Tijdstroom, 1981
  • Bennett & Mascetti, David & Daniela. Understanding Jewellery. Antique Collectors' Club. 1991.
  • Kunz, George Frederick. The Curious Lore of Precious Stones. Dover, 1971.
  • Robert Webster/ B.W. Anderson. Gems Their Sources, Descriptions and Identification 4th Edition. 1990.
  • Romero, Christie. Warman's Jewelry. Iola, WI, USA: Krause Publications, 2002
  • Scarisbrock, Diana. Ancestral Jewels: Treasures of Britain's Aristocracy. New York: The Vendome Press, 1990.
  • Sinkankas & Koivula, John & John I, and Becker, Gerhard. Peridot as an Interplanetary Gemstone. GIA Journal, Gems & Gemology. Spring 1992.

Online G&G articles on peridot

Lang Antiques
Lang Antiques