monoclinic Inosilicates
Spodumene (Prismatic)
Formula LiAlSi2O6
Crystal Structure
#! Species: Spodumene
#! System: Monoclinic (2/m)
#! Habit: Elongated prismatic with flat faces
monoclinic[2/m]:{110}@1.0 + {010}@0.8 + {100}@0.4 + {001}@1.2 | elongate(c:3.0)
monoclinic
2/m
{110} {010} {100} {001}
Quick Facts
Hardness
6.5
Specific Gravity
3.15
Refractive Index
1.66
Optical Character
Biaxial +
Physical Properties
- Crystal System
- monoclinic
- Hardness (Mohs)
- 6.5
- Specific Gravity
- 3.15
- Cleavage
- Perfect {110} at ~87°
- Fracture
- Uneven to splintery
- Lustre
- Vitreous
Optical Properties
- Refractive Index
- 1.66
- Birefringence
- 0.015
- Optical Character
- Biaxial +
- Dispersion
- 0.017
- Pleochroism
- moderate: Varies with variety / Paler shade
Characteristics
Colours
Pink-violet (kunzite)Green (hiddenite)YellowColorless
Localities
BrazilAfghanistanMadagascarUSA (California, North Carolina)Pakistan
Common Inclusions
Growth tubesFractures along cleavageFluid inclusions
Known Treatments
Irradiation (to produce green)
Crystal Forms
prismpinacoid
Diagnostic Features
Perfect prismatic cleavage; moderate RI; lithium pyroxene; produces kunzite (pink) and hiddenite (green)
Related Minerals
Other minerals in the monoclinic system
