cubic Synthetic synthetic spinel
Synthetic Spinel (Verneuil) (Boule)
Formula MgAl2O4
Crystal Structure
#! Species: Synthetic Spinel (Verneuil)
#! System: Cubic (m3m)
#! Habit: Octahedral habit from flame fusion boule
cubic[m3m]:{111}
cubic
m3m
{111}
Quick Facts
Hardness
8.0
Specific Gravity
3.64
Refractive Index
1.727
Optical Character
Isotropic (with anomalous birefringence)
Physical Properties
- Crystal System
- cubic
- Hardness (Mohs)
- 8.0
- Specific Gravity
- 3.64
- Cleavage
- None
- Fracture
- Conchoidal
- Lustre
- Vitreous
Optical Properties
- Refractive Index
- 1.727
- Birefringence
- 0
- Optical Character
- Isotropic (with anomalous birefringence)
- Dispersion
- 0.02
- Fluorescence
- Variable (blue shows strong red under LW UV due to cobalt)
Origin & Identification
- Origin
- Synthetic
- Growth Method
- Flame Fusion
- First Produced
- 1926
- Diagnostic Features
- Anomalous birefringence (ADR) in polariscope due to strain, RI much higher than natural (1.727 vs 1.712-1.717), gas bubbles, curved striae, often used as simulant for other gems (blue for sapphire, red for ruby, colourless for diamond)
Characteristics
Colours
BlueRedColourlessGreenYellowPink
Common Inclusions
Gas bubblesCurved striaeStrain patterns
Natural Counterpart
The natural gem this synthetic imitates
Related Minerals
Other minerals in the cubic system
