Boulder Opal and Topaz Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.98-2.25
  
3.49-3.57
  
Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
  
Subconchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle
  
Cleavage
Not Available
  
[001] Perfect
  
Mohs Hardness
5-6.5
  
8
  
Chemical Composition
SiO 2 + H 2OUlrich Henn and Claudio C.
  
Al2SiO4(F,OH)2
  
Boulder Opal and Topaz Chemical Formula
While comparing Boulder Opal and Topaz physical properties, the important data you should know is its chemical composition. Since chemical formula defines the molecular structure of the crystal, most of the physical properties like color, tenacity, solubility are governed by Boulder Opal and Topaz chemical formula.
- Chemical formula of Boulder Opal- SiO 2 + H 2OUlrich Henn and Claudio C.
- Chemical formula of Topaz- Al2SiO4(F,OH)2
Boulder Opal and Topaz Specific Gravity
Another important criteria for qualitative analysis of gemstones is Boulder Opal and Topaz Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Boulder Opal and Topaz Optical Properties during the identification of gemstone. Specific gravity of Boulder Opal is 3.49-3.57 whereas that of Topaz is 3.49-3.57.