Staurolite and Iolite Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.7-3.8
  
2.6-2.7
  
Fracture
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
  
Not Available
  
Cleavage
Distinct on {010}
  
3,1
  
Mohs Hardness
7-7.5
  
7-7.5
  
Chemical Composition
(Fe,Mg,Zn) 2Al 9(Si,Al) 4O 22(OH) 2Ulrich Henn and Claudio C.
  
Mg2Al4Si5O18
  
Staurolite and Iolite Chemical Formula
While comparing Staurolite and Iolite 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 Staurolite and Iolite chemical formula.
- Chemical formula of Staurolite- (Fe,Mg,Zn) 2Al 9(Si,Al) 4O 22(OH) 2Ulrich Henn and Claudio C.
- Chemical formula of Iolite- Mg2Al4Si5O18
Staurolite and Iolite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Staurolite and Iolite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Staurolite and Iolite Optical Properties during the identification of gemstone. Specific gravity of Staurolite is 2.6-2.7 whereas that of Iolite is 2.6-2.7.