Phenomenal gems

Phenomenal gemstones display optical effects caused by their internal structures or inclusions. These effects often require specific cutting styles (usually cabochon) and proper lighting to appreciate. As trends and collector interests evolve, these gems remain prized for their dynamic beauty and the artistry of revealing the most prized optical appearance.

Below are the phenomenal gemstones that exhibit distinctive optical effects

Asterism (“Star” Effect):
Gemstones -->  Star Sapphire, Star Ruby, Star Garnet, Star Diopside, Star Moonstone
Appearance --> A sharp, floating 4- or 6-rayed star visible when cut en cabochon under a single light source.
Chatoyancy (“Cat’s Eye” Effect):
Gemstones --> Cat’s Eye Chrysoberyl, Cat’s Eye Quartz, Cat’s Eye Tourmaline, Cat’s Eye Apatite
Appearance --> A bright line (“eye”) that moves across the dome of a cabochon as it’s turned.
Adularescence (Moonstone Glow):
Gemstones: Moonstone (Orthoclase/Plagioclase feldspar)
Appearance: Soft, billowy sheen (“floating light”) that seems to glide beneath the surface.
Labradorescence / Schiller:
Gemstones --> Labradorite, Spectrolite, Rainbow Moonstone (white labradorite)
Appearance --> Iridescent flashes of blue, green, gold, or multicolors against a darker base.
Aventurescence (Glittery Sparkle):
Gemstones --> Sunstone (Oregon or Indian), Aventurine Quartz, Iolite Sunstone
Appearance --> Metallic glitter or “sparkle” that shimmers as the stone moves.
Play-of-Color (Opalescence):
Gemstones --> Precious Opal (Black Opal, White Opal, Crystal Opal, Welo Opal)
Appearance --> Dynamic rainbow flashes against a body background.
Color-Change Phenomenon:
Gemstones -->  Alexandrite, Color-Change Garnet, Color-Change Sapphire
Appearance --> Noticeable shift (e.g., Green in Daylight --> Red under Incandescent).
Iridescence / Opalescence:
Gemstones -->  Opalized fossils, Ammolite, Labradorite variants
Appearance --> Rainbow-like sheen or play-of-color on polished surfaces.