Prehnite and Almandine Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.80-2.95
  
3.95-4.30
  
Fracture
Uneven, Yellow, White, UnevenWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Metallic
  
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
  
Cleavage
Distinct on [001]
  
none
  
Mohs Hardness
6-6.5
  
7-7.5
  
Chemical Composition
Ca2Al2Si3O12(OH)
  
Fe 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
  
Prehnite and Almandine Chemical Formula
While comparing Prehnite and Almandine 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 Prehnite and Almandine chemical formula.
- Chemical formula of Prehnite- Ca2Al2Si3O12(OH)
- Chemical formula of Almandine- Fe 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
Prehnite and Almandine Specific Gravity
Another important criteria for qualitative analysis of gemstones is Prehnite and Almandine Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Prehnite and Almandine Optical Properties during the identification of gemstone. Specific gravity of Prehnite is 3.95-4.30 whereas that of Almandine is 3.95-4.30.