- (Britain, Ireland, New Zealand, usually in the plural) A retroreflective device placed on a road surface as a marking that can be seen even at night.
- A glass marble with elongated colourful inclusions running through its axis.
- A gemstone exhibiting chatoyancy, a.k.a the cat's eye effect.
- (mineralogy) cymophane (translucent yellow chatoyant chrysoberyl)
retroreflective device placed on a road surface
glass marble with elongated inclusions
cymophane — see cymophane