The listing, Unique Deep Unique Yellow Cat's Eye- has an 'eye', please read has ended.
It appears a green in the photos but it is yellow. This one has a clear spot you can see through that magnifies what's below it. The spot appears as the dark mark seen in photo one but it is clear in person. It's on just one of the caps when the cat's eye ring is placed like an equator on the sphere. Really unique pieces were used quite often in healing and the eye developed.