Please note: This richterite is not shaped asbesos like.
FormulaNa[NaCa](Mg; Fe 2+)5Si8O22(OH)2
OriginKoksha Valley (Afghanistan)
Descriptionidiomorphic, elongated, transparent richterite crystal 
Classification (Lapis) Amphiboles
Crystal Systemmonoclinic
Hardness5,0 – 6,0
ColourBrown, yellow, green, brownish red; colorless to pale yellow in thin section
Streakwhite or grayish
Luminescenceyes 
Lustervitreous
Transparency (Opacity)transparent to translucent 
Cleavageperfect
Fractureuneven
Magnetismnegative
Geological SettingCommonly in contact metamorphosed limestones; in alkalic igneous rocks and carbonatites.
Specific Gravity3,1 g/cm3