Mexico
5.63 carats
© Rarestone.com
General Information | ||||||||||
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A variety or type of: | Feldspar | |||||||||
Chemical Formula |
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Physical Properties of Bytownite | ||||||||||
Mohs Hardness | 6 to 6.5Blue Chart Gem Identification (2010) , More from other references | |||||||||
Specific Gravity | 2.72 to 2.75Blue Chart Gem Identification (2010) , More from other references | |||||||||
Tenacity | BrittleGems, Sixth Edition (2006) , | |||||||||
Cleavage Quality | PerfectGemmological Tables (2004) , More from other references | |||||||||
Fracture | Uneven,ConchoidalGems, Sixth Edition (2006) , | |||||||||
Optical Properties of Bytownite | ||||||||||
Refractive Index | 1.561 to 1.583Blue Chart Gem Identification (2010) , More from other references | |||||||||
Optical Character | Biaxial/-Blue Chart Gem Identification (2010) , More from other references | |||||||||
Birefringence | 0.007 to 0.011Blue Chart Gem Identification (2010) , More from other references | |||||||||
Dispersion | Low (0.012)Gems, Sixth Edition (2006) , | |||||||||
Colour | ||||||||||
Colour (General) | Yellowish, reddish-brown, labradorescentGemmological Tables (2004) , More from other references | |||||||||
Transparency | Transparent,TranslucentGemmological Tables (2004) , More from other references | |||||||||
Lustre | Vitreous,Dull (Earthy)Gems, Sixth Edition (2006) , Vitreous to dull | |||||||||
Crystallography of Bytownite | ||||||||||
Crystal System | TriclinicBlue Chart Gem Identification (2010) , More from other references | |||||||||
Geological Environment | ||||||||||
Where found: | It is usually found as compact masses and grains in gabbros, norites, allivalites and anorthosites. It also forms from sodic metasomatism of metamorphic rocks. Often it occurs as part of compositionally zoned feldspars.Gems, Sixth Edition (2006) , | |||||||||
Further Information | ||||||||||
Mineral information: | Bytownite information at mindat.org |