1. A rare variety of chrysoberyl that appears green in daylight or fluorescent light and red under incandescent light, valued as a gemstone.
Usage: mineralogy; gemology

Examples

• The alexandrite in her engagement ring shifted from green to red as she moved it under different lighting.
• Alexandrite is one of the most prized gemstones because of its color-changing property.
• Collectors seek high-quality alexandrite specimens from Russia and Brazil.
• The jeweler explained that true alexandrite is much rarer and more expensive than synthetic versions.
• Under the museum's display lights, the alexandrite exhibited its characteristic pleochroism.