Golden honey, greenish-yellow, to olive-brown body color bisected by a razor-sharp silvery-white band of light (chatoyancy), often showing...
Chemical formula
BeAl₂O₄ with parallel microscopic rutile/growth tubes
Chrysoberyl • Chrysoberyl
Alexandrite
Exhibits the 'Alexandrite Effect'—appearing bluish-green to grass-green in daylight or fluorescent light and shifting to raspberry-red or purplish-red under incandescent/warm candlelight due to balanced transmission windows in the blue-green and red regions of the spectrum.
BeAl₂O₄ + Cr³⁺ (Beryllium Aluminum Oxide with trace Chromium)Mohs 8.5 Mohs
Mineralogical & Gemological Profile
| Mineral Family | Chrysoberyl |
|---|---|
| Mineral Species | Chrysoberyl |
| Gemological Variety | Alexandrite (Color-Change Chrysoberyl) |
| Chemical Composition | BeAl₂O₄ + Cr³⁺ (Beryllium Aluminum Oxide with trace Chromium) |
| Crystal System | Orthorhombic (Often forms cyclic 'trilling' twins) |
| Mohs Hardness | 8.5 Mohs |
| Specific Gravity | 3.70 – 3.78 |
| Refractive Index | 1.746 – 1.755 (Birefringence 0.008–0.010) |
Color Characteristics & Optical Behavior
Exhibits the 'Alexandrite Effect'—appearing bluish-green to grass-green in daylight or fluorescent light and shifting to raspberry-red or purplish-red under incandescent/warm candlelight due to balanced transmission windows in the blue-green and red regions of the spectrum.
Geological Context & Pakistani / Global Localities
Requires the rare geological convergence of beryllium (from granitic pegmatites) and chromium (from ultramafic rocks) in Russia, Sri Lanka, Brazil, Tanzania, and Madagascar.
Collector Interest & Rarity Factors
Natural alexandrite with a crisp 80–100% color change is one of the rarest and most valuable collector gemstones in the world.
Fine Jewelry Applications
Mohs 8.5 hardness and excellent toughness make it extraordinary for heirloom rings and pendants.
Treatment Considerations & Disclosure
Natural alexandrite is almost never heat-treated; however, synthetic flux-grown/Czochralski alexandrite and color-change synthetic corundum are common in the market. Laboratory certification is essential.
Care & Cleaning Instructions
Clean safely with warm soapy water and a soft brush.
Traditional Meaning
Traditional Symbolism & Cultural Heritage
Poetically described as 'emerald by day, ruby by night'; symbolizes adaptability, balance, and discernment. Official June birthstone.
Note: Cultural and birthstone traditions are presented strictly as historical folklore, never as scientifically verified medical or metaphysical effects.
Chrysoberyl
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