Alexandrite
What is Alexandrite?
Alexandrite is a variety of chrysoberyl that displays a color change depending on the lighting conditions. It’s primarily found in Russia, Sri Lanka, and Brazil. Alexandrite is often used as a gemstone and is popular for its unique color-changing ability.
Alexandrite is a rare and unique gemstone that changes color depending on the lighting conditions. Its unique appearance makes it a popular choice for jewelry, especially rings and pendants.
Chemical Classification | Inorganic - Oxide (Chrysoberyl) |
Color | Changes from green in daylight to reddish-purple under incandescent light. |
Streak | White |
Luster | Vitreous. |
Transparency | Transparent to translucent. |
Occurrence | Russia, Brazil, and Sri Lanka. |
Formation | Found in granitic pegmatites and mica schists. |
Diaphaneity | Transparent |
Cleavage | None |
Mohs Hardness | 8.5. |
Specific Gravity | Approximately 3.73. |
Diagnostic Properties | Color change under different lighting. |
Chemical Composition | BeAl3O12 |
Pleochroism | Strong; different colors can be observed when viewed from different angles. |
Crystal System | Orthorhombic (variety of Chrysoberyl) |
Optical Properties | Biaxial (+) |
Refractive Index | 1.741 - 1.760 |
Birefringence | 0.008 - 0.010 |
2V angle | Measured: 85° to 90° |
Dispersion | 0.014. |