Peridot (Olivine)

Big Photo

Myanmar
80.73 carats

Peridot is a gem-quality Olivine. The name "Peridot" is believed to have originated from the Arabic word faridat, meaning "gem", or alternatively, as the Oxford English Dictionary suggests, it came from classical Latin pæderot - a kind of opal.

The colour of peridot gems can vary from yellow- to olive- to brownish-green, depending on quantity of iron in the crystal structure. The most valued colour is a dark olive-green.

Peridot Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 
 
 
 
 

Peridot Gemstones by Size

This table shows distribution of Peridot gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:0.25 cts
Heaviest:80.73 cts
Average:5.66 cts
Total photos:92
Do you have a larger Peridot? Why not upload a photo?
0.25ct to 8.30ct8.30ct to 16.35ct16.35ct to 24.39ct24.39ct to 32.44ct32.44ct to 40.49ct40.49ct to 48.54ct48.54ct to 56.59ct56.59ct to 64.63ct64.63ct to 72.68ct72.68ct to 80.73ct
General Information
Varieties/Types:
Fayalite - An iron-dominant olivine mineral.
Forsterite - A magnesium-dominant olivine mineral.
Other Names/Trade Names:
Chemical Formula
(Mg,Fe)
 
2
SiO
 
4
Arthur Thomas, Gemstones (2009)
Photos of natural/un-cut material from mindat.org
Peridot Simulants
Imitations are often constructed of corundum and spinel syntheses. Evergreen bottle glass can be mistaken for peridot. - Gemstones of the world, Walter Schumann, 2001, p 158
Physical Properties of Peridot
Mohs Hardness6.5 to 7
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Specific Gravity3.27 to 3.48
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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TenacityBrittle
Walter Schumann, Gemstones of the world (2001)
Cleavage QualityIndistinct
Walter Schumann, Gemstones of the world (2001)
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FractureConchoidal
Arthur Thomas, Gemstones (2009)
Optical Properties of Peridot
Refractive Index1.650 to 1.710
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Optical CharacterBiaxial/+
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Birefringence0.035 to 0.038
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) DoublingMore from other references
PleochroismWeak: yellow-green - green - (colorless)
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Dispersion0.020
Arthur Thomas, Gemstones (2009)
ChatoyancyRarely star 4/6
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Colour
Colour (General)Green, yellow-green, brown-green
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
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Causes of ColourYellowish green, Fe2+ in octahedral series coordination. Green, Fe2+ with minor amounts of Cr3+ in octahedral coordination
W. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011)
TransparencyTransparent
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
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LustreVitreous,Greasy
Walter Schumann, Gemstones of the world (2001)
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Fluorescence & other light emissions
Fluorescence (General)None
Walter Schumann, Gemstones of the world (2001)
Crystallography of Peridot
Crystal SystemOrthorhombic
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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HabitShort, compact prisms, vertically striated.
Walter Schumann, Gemstones of the world (2001)
More from other references
Spectrographic Data
Calculated Spectra:
Click spectra for more information
Peridot - Locality: Pakistan
Peridot - Locality: Pakistan
Inclusions in Peridot
Disk-like "lily pad", black chromite octahedrons, glassy rounded drops - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 4

Discoidal cracks often with a dark chromite crystal at the centre (lily pads), needle-like inclusions, healing cracks, minute fluid droplets - Gemmological Tables, Ulrich Henn and Claudio C. Milisenda, 2004, p 17
Further Information
Mineral information:Peridot information at mindat.org
Significant Gem Localities
China
 
  • Jilin Province (Manchuria; Dongbei Region)
    • Jilin Prefecture
      • Jiaohe Co.
Henn (1999)
Egypt
 
  • Red Sea
Brooker et al. (2004)
Ethiopia
 
  • Sidamo-Borana Province
    • Megado
Kammerling and Koivula (1995)
Kyrgyzstan
 
  • Naryn Oblast
Myanmar
 
  • Mandalay Division
    • Pyin-Oo-Lwin District
      • Mogok Township
        • Bernardmyo
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
          • Pyaung Gaung
Kammerling et al. (1994)
Ted Themelis (2008) Gems & mines of Mogok
Norway
 
  • Møre og Romsdal
    • Vanylven
      • Almklovdalen
[var: Forsterite] mindat.org
Pakistan
 
  • Khyber Pakhtunkhwa (North-West Frontier Province)
    • Mansehra District
      • Kaghan Valley
gemexplorer.org
Hammer (2004)
Sri Lanka
 
  • Sabaragamuwa Province
    • Ratnapura District
      • Ratnapura
[var: Forsterite]
USA
 
  • Arizona
    • Gila Co.
      • San Carlos Indian Reservation
        • San Carlos
gemexplorer.org
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