cubic Nesosilicates
Andradite (Rhombic Dodecahedron)
Ca3Fe2(SiO4)3
Crystal Structure
#! Species: Andradite
#! System: Cubic (m3m)
#! Habit: Dodecahedron with trapezohedron
cubic[m3m]:{110}@1.0 + {211}@0.7
cubic
m3m
{110} {211}
Quick Facts
Hardness
6.5
Specific Gravity
3.82
Refractive Index
1.855
Optical Character
Isotropic
Physical Properties
Crystal Systemcubic
Hardness (Mohs)6.5
Specific Gravity3.82
CleavageNone
FractureConchoidal to uneven
LustreAdamantine to vitreous
Optical Properties
Refractive Index1.855
Optical CharacterIsotropic
Dispersion0.057
PleochroismNone (isotropic)
Colours
Green (demantoid)Yellow-green (topazolite)Black (melanite)Brown
Localities
Russia (Urals)NamibiaMadagascarIranItaly
Common Inclusions
Horsetail (chrysotile) in demantoidCrystal inclusions
Known Treatments
None commonly applied
Crystal Forms
dodecahedrontrapezohedron
Diagnostic Features
Highest dispersion of any garnet (0.057); adamantine lustre; very high RI
Related Minerals
Other minerals in the cubic system
