trigonal Synthetic synthetic corundum
Flux-Grown Ruby (Crystal)
Formula Al2O3:Cr
Crystal Structure
#! Species: Flux-Grown Ruby
#! System: Trigonal (-3m)
#! Habit: Tabular to prismatic from flux growth
trigonal[-3m]:{10-10}@1.0 + {10-11}@0.8 + {0001}@0.5
trigonal
-3m
{10-10} {10-11} {0001}
Quick Facts
Hardness
9.0
Specific Gravity
3.99
Refractive Index
1.762
Optical Character
Uniaxial -
Physical Properties
- Crystal System
- trigonal
- Hardness (Mohs)
- 9.0
- Specific Gravity
- 3.99
- Cleavage
- None (parting on {0001} and {10-11})
- Fracture
- Conchoidal
- Lustre
- Vitreous to adamantine
Optical Properties
- Refractive Index
- 1.762
- Birefringence
- 0.008
- Optical Character
- Uniaxial -
- Dispersion
- 0.018
- Pleochroism
- strong: purplish-red / orangey-red
- Fluorescence
- Strong red (LW and SW UV)
Origin & Identification
- Origin
- Synthetic
- Growth Method
- Flux
- Manufacturer
- Chatham, Kashan, Knischka, Ramaura
- First Produced
- 1960
- Diagnostic Features
- Flux remnants (wispy veils, fingerprints of flux), platinum platelets from crucible, characteristic flux feather inclusions, may contain twisted veils resembling natural silk
Characteristics
Colours
RedPinkish-red
Common Inclusions
Flux remnants (wispy veils)Platinum plateletsFlux fingerprints
Natural Counterpart
The natural gem this synthetic imitates
Related Minerals
Other minerals in the trigonal system
