Tiger's Eye

Big Photo

Thailand
13.6 carats
© gemselect.com

Tiger's eye is a variety of Quartz which exhibits a fascinating and constantly shifting light effect since the alternating silky gold and brown bands keep reversing their appearance with the slightest change in position of the light source or of the stone. This effect is caused by parallel intergrowth of Quartz crystals and altered amphibole fibres that mostly turned into limonite.

Tiger's eye was believed to be a Quartz pseudomorph after the blue asbestos known as crocidolite. The iron from the decomposed crocidolite has oxidized to a brown colour, keeping the fibrous structure. Recently Heaney and Fisher (2003) gave another interpretation of Tiger's eye origin: ".. we argue that tiger's-eye classically exemplifies synchronous mineral growth through a crack-seal vein-filling process."

Tiger's Eye is widely used as an ornamental and lapidary rock.

Tiger's Eye Gemstones by Colour

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

Tiger's Eye Gemstones by Size

This table shows distribution of Tiger's Eye 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:5.34 cts
Heaviest:511.94 cts
Average:40.13 cts
Total photos:29
Do you have a larger Tiger's Eye? Why not upload a photo?
5.34ct to 56.00ct56.00ct to 106.66ct106.66ct to 157.32ct157.32ct to 207.98ct207.98ct to 258.64ct258.64ct to 309.30ct309.30ct to 359.96ct359.96ct to 410.62ct410.62ct to 461.28ct461.28ct to 511.94ct
General Information
A variety or type of:Quartz
Varieties/Types:
Chemical Formula
SiO
 
2
Michael O’Donoghue, Gems, Sixth Edition (2006)
Photos of natural/un-cut material from mindat.org
Tiger's Eye Treatments
May be bleached to lighten the color and dyed to any color. Also heat-treated to produce the dark red "Bull's eye" - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7
Physical Properties of Tiger's Eye
Mohs Hardness6.5 to 7
Walter Schumann, Gemstones of the world (2001)
More from other references
Specific Gravity2.58 to 2.64
Walter Schumann, Gemstones of the world (2001)
More from other references
Cleavage QualityNone
Arthur Thomas, Gemstones (2009)
FractureConchoidal
Michael O’Donoghue, Gems, Sixth Edition (2006)
Optical Properties of Tiger's Eye
Refractive Index1.534 to 1.540
Walter Schumann, Gemstones of the world (2001)
More from other references
Optical CharacterUniaxial/+
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
BirefringenceNone
Walter Schumann, Gemstones of the world (2001)
PleochroismAbsent
Walter Schumann, Gemstones of the world (2001)
DispersionNone
Walter Schumann, Gemstones of the world (2001)
ChatoyancyChatoyant
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Colour
Colour (General)Gold-yellow, gold-brown
Walter Schumann, Gemstones of the world (2001)
More from other references
TransparencyOpaque
Walter Schumann, Gemstones of the world (2001)
More from other references
LustreVitreous
Gemdat.org, Management Team (2012)
Fluorescence & other light emissions
Fluorescence (General)None
Walter Schumann, Gemstones of the world (2001)
Crystallography of Tiger's Eye
Crystal SystemTrigonal
Gemdat.org, Management Team (2012)
HabitFibrous aggregate
Walter Schumann, Gemstones of the world (2001)
Further Information
Mineral information:Tiger's Eye information at mindat.org
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