Browse by Optical Phenomena
Discover gemstones with unique optical effects. From the star patterns of asterism to the color-shifting magic of alexandrite, these phenomena make certain gems truly extraordinary.
All Optical Phenomena
Star Ruby
6 gemsStar-shaped light reflection caused by needle-like inclusions arranged in intersecting patterns.
Trichroism
4 gemsDisplay of different colors when viewed from different crystallographic directions.
Fluorescent Ruby
3 gemsEmission of visible light when exposed to ultraviolet radiation.
Color-Change Sapphire
3 gemsGems that display different colors under different light sources (daylight vs incandescent).
Cat's Eye
3 gemsA luminous band of light across the gem's surface, resembling a cat's eye.
Labradorescence
3 gemsSpectral colors that appear to move across the stone when viewed from different angles.
Play of Color
3 gemsFlashes of spectral colors that change with viewing angle, iconic in opals.
Fire Iridescence
2 gemsRainbow-like colors caused by light diffraction on thin layers within the gem.
Adularescence
1 gemA floating, billowy light effect seen in moonstones, caused by light scattering.
Aventurescence
1 gemGlittery effect caused by tiny reflective inclusions, common in aventurine.
Understanding Optical Phenomena
Optical phenomena in gemstones are caused by the interaction of light with a gem's internal structure. These effects can result from inclusions, crystal structure, or layered composition. Phenomena like asterism and chatoyancy typically require cabochon cutting to display their effects properly.
Reflection Effects
Asterism, chatoyancy, and aventurescence are caused by light reflecting off inclusions within the gem.
Interference Effects
Iridescence, play of color, and labradorescence result from light interfering as it passes through thin layers.
Luminescence Effects
Fluorescence and phosphorescence occur when gems absorb and re-emit light energy at different wavelengths.