cubic Nesosilicates
Andradite (Rhombic Dodecahedron)
Ca3Fe2(SiO4)3
Quick Facts
Hardness
6.5
Specific Gravity
3.82
Refractive Index
1.855
Optical Character
Isotropic
Crystal Structure
#! Species: Andradite
#! System: Cubic (m3m)
#! Habit: Dodecahedron with trapezohedron
cubic[m3m]:{110}@1.0 + {211}@0.7
cubic
m3m
{110} {211}
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
Interactive Preview
Open this crystal in the CDL Playground to rotate, export, and explore in 3D.
Open in Playground #! Species: Andradite
#! System: Cubic (m3m)
#! Habit: Dodecahedron with trapezohedron
cubic[m3m]:{110}@1.0 + {211}@0.7
Related Minerals
Other minerals in the cubic system
