cubic Nesosilicates
Hessonite (Trapezohedron)
Formula Ca3Al2(SiO4)3
Crystal Structure
#! Species: Hessonite (Grossular variety)
#! System: Cubic (m3m)
#! Habit: Trapezohedron with dodecahedron
cubic[m3m]:{211}@1.0 + {110}@0.5
cubic
m3m
{211} {110}
Quick Facts
Hardness
6.5
Specific Gravity
3.57
Refractive Index
1.742
Optical Character
Isotropic
Physical Properties
- Crystal System
- cubic
- Hardness (Mohs)
- 6.5
- Specific Gravity
- 3.57
- Cleavage
- None
- Fracture
- Conchoidal to uneven
- Lustre
- Vitreous to resinous
Optical Properties
- Refractive Index
- 1.742
- Optical Character
- Isotropic
- Dispersion
- 0.027
- Pleochroism
- None (isotropic)
Characteristics
Colours
Cinnamon orangeHoney yellowOrange-brownReddish-orange
Localities
Sri LankaIndiaTanzaniaBrazilCanadaMadagascar
Common Inclusions
Roiled appearance (diagnostic)Diopside crystalsApatiteZircon crystals
Known Treatments
None commonly applied
Crystal Forms
trapezohedrondodecahedron
Diagnostic Features
Distinctive roiled or 'heat-haze' internal appearance; orange to cinnamon colour; grossular variety
Related Minerals
Other minerals in the cubic system
