Opal and Almandine Physical Properties
Tenacity
BrittleWalter Schumann
  
Not Available
  
Solubility
hot salt water
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.98-2.25
  
3.95-4.30
  
Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Brittle
  
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
  
Cleavage
None
  
none
  
Mohs Hardness
5-6.5
  
7-7.5
  
Chemical Composition
SiO2 · nH2O
  
Fe 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
  
Opal and Almandine Chemical Formula
While comparing Opal and Almandine 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 Opal and Almandine chemical formula.
- Chemical formula of Opal- SiO2 · nH2O
- Chemical formula of Almandine- Fe 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
Opal and Almandine Specific Gravity
Another important criteria for qualitative analysis of gemstones is Opal and Almandine Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Opal and Almandine Optical Properties during the identification of gemstone. Specific gravity of Opal is 3.95-4.30 whereas that of Almandine is 3.95-4.30.