Iolite and Herderite Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.6-2.7
  
2.90-3.02
  
Fracture
Not Available
  
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
  
Cleavage
3,1
  
Indistinct on {110}
  
Mohs Hardness
7-7.5
  
5-5.5
  
Chemical Composition
Mg2Al4Si5O18
  
CaBePO 4(F,OH)Ulrich Henn and Claudio C.
  
Iolite and Herderite Chemical Formula
While comparing Iolite and Herderite 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 Iolite and Herderite chemical formula.
- Chemical formula of Iolite- Mg2Al4Si5O18
- Chemical formula of Herderite- CaBePO 4(F,OH)Ulrich Henn and Claudio C.
Iolite and Herderite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Iolite and Herderite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Iolite and Herderite Optical Properties during the identification of gemstone. Specific gravity of Iolite is 2.90-3.02 whereas that of Herderite is 2.90-3.02.