Neptunite and Grandidierite Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.19-3.23
  
2.85-3.00
  
Fracture
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
  
Brittle, UnevenArthur Thomas, Gemstones (2009), Brittle, Uneven
  
Cleavage
{110} good
  
Perfect
  
Mohs Hardness
5-6
  
7.5
  
Chemical Composition
KNa 2Li(Fe2+ ,Mn2+ ) 2Ti 2Si 8O 24Michael OâDonoghue , Gems, Sixth Edition (2006)
  
(Mg,Fe)Al 3(BO 4)(SiO 4)OUlrich Henn and Claudio C.
  
Neptunite and Grandidierite Chemical Formula
While comparing Neptunite 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 Neptunite and Grandidierite chemical formula.
- Chemical formula of Neptunite- KNa 2Li(Fe2+ ,Mn2+ ) 2Ti 2Si 8O 24Michael OâDonoghue , Gems, Sixth Edition (2006)
- Chemical formula of Grandidierite- (Mg,Fe)Al 3(BO 4)(SiO 4)OUlrich Henn and Claudio C.
Neptunite and Grandidierite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Neptunite and Grandidierite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Neptunite and Grandidierite Optical Properties during the identification of gemstone. Specific gravity of Neptunite is 2.85-3.00 whereas that of Grandidierite is 2.85-3.00.