Actinolite

Category: Inosilicates

 

Chemical formula: Ca2(Mg4.5-2.5Fe2+0.5-2.5) Si8O22(OH)2

 

Mohs scale hardness: 5–6

 

Specific gravity: 3.00 (+0.10, -0.05)

 

Optical properties: Biaxial (-)

 

Refractive index: nα = 1.613–1.628 nβ = 1.627–1.644 nγ = 1.638–1.655

 

Birefringence: 0.0250-0.0270

 

2V angle: 78–82° (calc), 84-73° (meas)

 

 

Done