Agate Opal

Opal that is banded like agate or onyx.
General Information
A variety or type of:Common Opal, which is a variety of Opal
Chemical Formula
SiO
 
2
· nH
 
2
O
Walter Schumann, Gemstones of the world (2001)
Physical Properties of Agate Opal
Mohs Hardness5.5 to 6.5
Walter Schumann, Gemstones of the world (2001)
Specific Gravity1.98 to 2.50
Walter Schumann, Gemstones of the world (2001)
TenacityBrittle
Walter Schumann, Gemstones of the world (2001)
Cleavage QualityNone
Walter Schumann, Gemstones of the world (2001)
FractureConchoidal,Splintery
Walter Schumann, Gemstones of the world (2001)
Optical Properties of Agate Opal
Refractive Index1.37 to 1.52
Walter Schumann, Gemstones of the world (2001)
BirefringenceNone
Walter Schumann, Gemstones of the world (2001)
PleochroismAbsent
Walter Schumann, Gemstones of the world (2001)
DispersionNone
Walter Schumann, Gemstones of the world (2001)
Colour
Colour (General)All colours
Walter Schumann, Gemstones of the world (2001)
TransparencyTranslucent,Opaque
Walter Schumann, Gemstones of the world (2001)
Crystallography of Agate Opal
Crystal SystemAmorphous
Walter Schumann, Gemstones of the world (2001)
Further Information
Mineral information:Agate Opal information at mindat.org
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