Opal and Periclase Physical Properties
Tenacity
BrittleWalter Schumann
  
Brittle
  
Solubility
hot salt water
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
1.98-2.25
  
3.7-3.9
  
Fracture
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Brittle
  
Conchoidal, Brittle
  
Cleavage
None
  
{001} perfect; {111} imperfect, may exhibit parting on , {011}
  
Mohs Hardness
5-6.5
  
5.5-6
  
Chemical Composition
SiO2 · nH2O
  
MgOMichael OâDonoghue , Gems, Sixth Edition (2006)
  
Opal and Periclase Chemical Formula
While comparing Opal and Periclase 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 Periclase chemical formula.
- Chemical formula of Opal- SiO2 · nH2O
- Chemical formula of Periclase- MgOMichael OâDonoghue , Gems, Sixth Edition (2006)
Opal and Periclase Specific Gravity
Another important criteria for qualitative analysis of gemstones is Opal and Periclase Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Opal and Periclase Optical Properties during the identification of gemstone. Specific gravity of Opal is 3.7-3.9 whereas that of Periclase is 3.7-3.9.