Harlequin Opal

A variety of Precious Opal in which the play-of-color is arranged in a vivid harlequin (therefore its name), diamond-shaped, chessboard or rectangular-shaped pattern. Counted among the most desirable opals.
General Information
A variety or type of:Precious Opal, which is a variety of Opal
Chemical Formula
SiO
 
2
· nH
 
2
O
Walter Schumann, Gemstones of the world (2001)
Physical Properties of Harlequin 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 Harlequin 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)
TransparencyTransparent,Translucent
Walter Schumann, Gemstones of the world (2001)
Crystallography of Harlequin Opal
Crystal SystemAmorphous
Walter Schumann, Gemstones of the world (2001)
HabitKidney- or grape-shaped aggregates
Walter Schumann, Gemstones of the world (2001)
Further Information
Mineral information:Harlequin Opal information at mindat.org
Significant Gem Localities
Australia
 
  • New South Wales
    • Finch Co.
  • South Australia
    • Central North
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