Binghamite

A chatoyant variety of Chalcedony containing fibres of goethite and/or hematite. Similar to tiger's eye.
General Information
A variety or type of:Chalcedony, which is a variety of Quartz
Chemical Formula
SiO
 
2
Arthur Thomas, Gemstones (2009)
Physical Properties of Binghamite
Mohs Hardness6.5 to 7
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Specific Gravity2.55 to 2.70
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Optical Properties of Binghamite
Refractive Index1.530 to 1.543
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Optical CharacterUniaxial/+
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Birefringence0.003 to 0.009
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
ChatoyancyYes
Gemdat.org, Management Team (2012)
Colour
Colour (General)Yellowish to reddish
Gemdat.org, Management Team (2012)
TransparencyTranslucent,Opaque
Arthur Thomas, Gemstones (2009)
LustreWaxy,Resinous
Arthur Thomas, Gemstones (2009)
Crystallography of Binghamite
Crystal SystemTrigonal
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
HabitFibrous to grained aggregate
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Inclusions in Binghamite
Dense and parallel fibres of Goethite and/or Hematite
Further Information
Mineral information:Binghamite information at mindat.org
Significant Gem Localities
USA
 
  • Minnesota
    • Crow Wing Co.
Gemstones of the world, W. Schumann, 2001, p. 204
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