Actinolite (Prismatic) crystal structure
monoclinic Inosilicates

Actinolite (Prismatic)

Ca2(Mg,Fe)5Si8O22(OH)2

Quick Facts

Hardness
5.0
Specific Gravity
3.0
Refractive Index
1.613
Optical Character
Biaxial -

Crystal Structure

#! Species: Actinolite #! System: Monoclinic (2/m) #! Habit: Elongated prismatic monoclinic[2/m]:{110}@1.0 + {010}@0.8 + {100}@0.4 + {001}@0.9 | elongate(c:3.0)
monoclinic
2/m
{110} {010} {100} {001}

Physical Properties

Crystal Systemmonoclinic
Hardness (Mohs)5.0
Specific Gravity3.0
CleavagePerfect {110} at 56°
FractureSplintery
LustreVitreous to silky

Optical Properties

Refractive Index1.613
Birefringence0.022
Optical CharacterBiaxial -
Pleochroismmoderate: Yellow-green / Deep green

Colours

GreenDark greenGrey-green

Localities

TanzaniaMadagascarCanadaNew ZealandTaiwan

Common Inclusions

Fibrous structureMagnetite inclusions

Known Treatments

None commonly applied

Crystal Forms

prismpinacoid

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#! Species: Actinolite #! System: Monoclinic (2/m) #! Habit: Elongated prismatic monoclinic[2/m]:{110}@1.0 + {010}@0.8 + {100}@0.4 + {001}@0.9 | elongate(c:3.0)