Gemological properties of Afganite

 

Afganite Properties

S.No	Description	Physical properties / Optical properties
1	Chemical formula	(Na,Ca,K)8(Si,Al)12O24(SO4,Cl,CO3)3•(H2O)
2	Group	Cancrinite
3	Crystal system	Hexagonal
4	Color	Mostly Blue
5	Specific gravity	2.56 to 2.85
6	Hardness	5.5 to 6
7	Durability	Fair
8	R.I	1.522 to 1.533
9	Fluoresce	Bright orange in long waves / inert in short waves
10	Optical sign	Uniaxial negative
11	Inclusions	May be speckled of dark blue inclusions of Lazurite