Fibrolite

Big Photo

Myanmar
4.81 carats
© Palagems

Fibrolite is a fibrous form of Sillimanite. This name is because the mineral appears like a bunch of fibres twisted together when viewed in thin section or even by the naked eye.

Fibrolite Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 
General Information
A variety or type of:Sillimanite
Chemical Formula
Al
 
2
SiO
 
5
Arthur Thomas, Gemstones (2009)
Physical Properties of Fibrolite
Mohs Hardness6 to 7
Arthur Thomas, Gemstones (2009)
Specific Gravity3.14 to 3.25
Arthur Thomas, Gemstones (2009)
Cleavage QualityPerfect
Arthur Thomas, Gemstones (2009)
FractureUneven
Arthur Thomas, Gemstones (2009)
Optical Properties of Fibrolite
Refractive Index1.658 to 1.678
Arthur Thomas, Gemstones (2009)
Optical CharacterBiaxial/+
Arthur Thomas, Gemstones (2009)
BirefringenceStrong
Arthur Thomas, Gemstones (2009)
PleochroismDistinct
Arthur Thomas, Gemstones (2009)
Dispersion0.015
Arthur Thomas, Gemstones (2009)
Colour
Colour (General)Blue, brown, colourless, green, grey
Arthur Thomas, Gemstones (2009)
TransparencyTransparent,Translucent
Arthur Thomas, Gemstones (2009)
LustreVitreous
Arthur Thomas, Gemstones (2009)
Crystallography of Fibrolite
Crystal SystemOrthorhombic
Arthur Thomas, Gemstones (2009)
HabitPrismatic
Arthur Thomas, Gemstones (2009)
Further Information
Mineral information:Fibrolite information at mindat.org
Significant Gem Localities
Myanmar
 
  • Mandalay Region
    • Pyin-Oo-Lwin District
      • Mogok Township
        • Mogok Valley
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
        • Pein-Pyit (Painpyit; Pyan Pyit)
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
Ted Themelis (2008) Gems & mines of Mogok
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