orthorhombic Synthetic synthetic chrysoberyl
Synthetic Alexandrite (Czochralski Boule)
Formula BeAl2O4:Cr
Crystal Structure
#! Species: Synthetic Alexandrite (Czochralski)
#! System: Orthorhombic (mmm)
#! Habit: Chrysoberyl habit from Czochralski boule
orthorhombic[mmm]:{110}@1.0 + {010}@0.6 + {111}@0.4
orthorhombic
mmm
{110} {010} {111}
Quick Facts
Hardness
8.5
Specific Gravity
3.71
Refractive Index
1.744
Optical Character
Biaxial +
Physical Properties
- Crystal System
- orthorhombic
- Hardness (Mohs)
- 8.5
- Specific Gravity
- 3.71
- Cleavage
- Distinct on {110}, poor on {010}
- Fracture
- Conchoidal
- Lustre
- Vitreous
Optical Properties
- Refractive Index
- 1.744
- Birefringence
- 0.011
- Optical Character
- Biaxial +
- Dispersion
- 0.015
- Pleochroism
- very strong: green / orange / purple-red
- Phenomenon
- Colour change (alexandrite effect)
- Fluorescence
- Strong red (LW UV)
Origin & Identification
- Origin
- Synthetic
- Growth Method
- Czochralski
- Manufacturer
- Creative Crystals, Seiko
- First Produced
- 1972
- Diagnostic Features
- Curved striae, gas bubbles (Czochralski method), too-perfect colour change, no natural inclusions, may show strong red fluorescence
Characteristics
Colours
Green (daylight)Red (incandescent)
Common Inclusions
Curved striaeGas bubblesIridescent platelets
Natural Counterpart
The natural gem this synthetic imitates
Related Minerals
Other minerals in the orthorhombic system
