Periclase and Onyx Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.7-3.9
  
2.55-2.70
  
Fracture
Conchoidal, Brittle
  
Not Available
  
Cleavage
{001} perfect; {111} imperfect, may exhibit parting on , {011}
  
Indiscernible
  
Mohs Hardness
5.5-6
  
6.5-7
  
Chemical Composition
MgOMichael OâDonoghue , Gems, Sixth Edition (2006)
  
SiO2
  
Periclase and Onyx Chemical Formula
While comparing Periclase and Onyx 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 Periclase and Onyx chemical formula.
- Chemical formula of Periclase- MgOMichael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Onyx- SiO2
Periclase and Onyx Specific Gravity
Another important criteria for qualitative analysis of gemstones is Periclase and Onyx Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Periclase and Onyx Optical Properties during the identification of gemstone. Specific gravity of Periclase is 2.55-2.70 whereas that of Onyx is 2.55-2.70.