Staurolite and Grandidierite Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.7-3.8
  
2.85-3.00
  
Fracture
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
  
Brittle, UnevenArthur Thomas, Gemstones (2009), Brittle, Uneven
  
Cleavage
Distinct on {010}
  
Perfect
  
Mohs Hardness
7-7.5
  
7.5
  
Chemical Composition
(Fe,Mg,Zn) 2Al 9(Si,Al) 4O 22(OH) 2Ulrich Henn and Claudio C.
  
(Mg,Fe)Al 3(BO 4)(SiO 4)OUlrich Henn and Claudio C.
  
Staurolite and Grandidierite Chemical Formula
While comparing Staurolite and Grandidierite 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 Grandidierite chemical formula.
- Chemical formula of Staurolite- (Fe,Mg,Zn) 2Al 9(Si,Al) 4O 22(OH) 2Ulrich Henn and Claudio C.
- Chemical formula of Grandidierite- (Mg,Fe)Al 3(BO 4)(SiO 4)OUlrich Henn and Claudio C.
Staurolite and Grandidierite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Staurolite and Grandidierite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Staurolite and Grandidierite Optical Properties during the identification of gemstone. Specific gravity of Staurolite is 2.85-3.00 whereas that of Grandidierite is 2.85-3.00.