monoclinic Inosilicates
Augite (Prismatic)
Formula (Ca,Na)(Mg,Fe,Al)(Si,Al)2O6
Crystal Structure
#! Species: Augite
#! System: Monoclinic (2/m)
#! Habit: Short prismatic monoclinic
monoclinic[2/m]:{010}@1.0 + {110}@0.8 + {100}@0.6 + {001}@0.4
monoclinic
2/m
{010} {110} {100} {001}
Quick Facts
Hardness
5.5
Specific Gravity
3.2
Refractive Index
1.68
Optical Character
Biaxial +
Physical Properties
- Crystal System
- monoclinic
- Hardness (Mohs)
- 5.5
- Specific Gravity
- 3.2
- Cleavage
- Good {110} at ~87°
- Fracture
- Uneven to conchoidal
- Lustre
- Vitreous to resinous
Optical Properties
- Refractive Index
- 1.68
- Birefringence
- 0.023
- Optical Character
- Biaxial +
Characteristics
Colours
Dark greenBlackBrown
Localities
Worldwide (common rock-forming mineral)Italy (Vesuvius)Canada
Common Inclusions
Exsolution lamellae
Known Treatments
None
Crystal Forms
prismpinacoid
Related Minerals
Other minerals in the monoclinic system
