Afghanite and Goethite Physical Properties
Tenacity
Not Available
  
Not Available
  
Solubility
Not Available
  
HCl soluble
  
Durability
Not Available
  
Not Available
  
Specific Gravity
2.55-2.65
  
4.27-4.29
  
Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle, Conchoidal, Brittle
  
Uneven, torn surfaces, (e.g. fractured metals)., Uneven, Gemstones (2009), torn surfaces, (e.g. fractured metals).
  
Cleavage
Perfect {10 1 0}
  
Perfect {010}
  
Mohs Hardness
5.5-6
  
5-5.5
  
Chemical Composition
(Na,Ca,K) 8(Si,Al) 12O 24(SO 4,Cl,CO 3) 3(H 2O)Arthur Thomas , Gemstones (2009)
  
FeO(OH)Arthur Thomas , Gemstones (2009)
  
Afghanite and Goethite Chemical Formula
While comparing Afghanite and Goethite 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 Afghanite and Goethite chemical formula.
- Chemical formula of Afghanite- (Na,Ca,K) 8(Si,Al) 12O 24(SO 4,Cl,CO 3) 3(H 2O)Arthur Thomas , Gemstones (2009)
- Chemical formula of Goethite- FeO(OH)Arthur Thomas , Gemstones (2009)
Afghanite and Goethite Specific Gravity
Another important criteria for qualitative analysis of gemstones is Afghanite and Goethite Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Afghanite and Goethite Optical Properties during the identification of gemstone. Specific gravity of Afghanite is 4.27-4.29 whereas that of Goethite is 4.27-4.29.