Metales Barajas MB

03/01/2026

18/10/2025

Here’s our quick list of some of the most dazzling special optical effects, called phenomena, in the world of gems:

- Asterism / Star Gem: When light hits tiny needle-like inclusions just right, gems like sapphire and ruby can show a mobile star pattern on their surface.
- Cat’s Eye (Chatoyancy): A single bright band of light stretches across the gem, like the slit pupil of a cat. Most famous in chrysoberyl, it can also appear in moonstone, emerald and tourmaline.
- Labradorescence: A dramatic flash of iridescent blue, green or gold seen in labradorite. Caused by layers of feldspar inside the stone scattering light.
- Play-of-Color: The rainbow fire seen in precious opals. Caused by microscopic spheres inside the gem that diffract light like a prism.
- Adularescence: A soft, floating sheen (often bluish) that hovers just beneath the surface of moonstone.
- Iridescence (called Orient in pearls): A rainbow-like shimmer that drifts across the surface. Common in pearls, fire agate, and ammolite.
- Color Change: A gems color appears different under varying light. Most famously seen in alexandrite, which can shift from red to green, but can also occur in sapphires and garnets.
- Aventurescence: A glittery, metallic sparkle caused by tiny mineral inclusions. Most famously seen in aventurine quartz and sunstone.

Which phenomenal gem is your favorite?