Alexandrite
Real mineral · very rare · BeAl₂O₄
Chrysoberyl that shifts from green in daylight to red under incandescent light due to absorption of light at the boundary between red and green wavelengths. One of the rarest colour-change minerals, first discovered in the Ural Mountains in 1830.
Identity
- Formula
- BeAl₂O₄
- Chemical class
- oxide
- Also known as
- Color-change chrysoberyl
Crystallography
- Crystal system
- orthorhombic
- Habits
- tabular, prismatic
- Fracture
- conchoidal
Physical properties
- Mohs hardness
- 8.5
- Density
- 3.73 g/cm³
- Luster
- vitreous
- Colors
- green, blue-green, red, purple
- Streak
- white
- Transparency
- transparent
Geology
- Origins
- metamorphic, igneous
- Host rocks
- marble, pegmatite, dolomite
- Associated minerals
- Beryl, Tourmaline, Corundum
- Geography
- Russia (Ural Mountains), Brazil, Sri Lanka, Tanzania, India
Classification
- Rarity
- very rare
- Gem quality
- Yes
Arcane properties
- Affinity
- arcane, time
- Effects
- illusion, time
- Planar origin
- Material Plane
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