Ulexite

Also called the "TV rock" or "television stone," ulexite is known for its unusual optical characteristics, notably its ability to transmit images through its natural fibers. A piece of writing placed underneath the stone appears on the surface of the stone! Ulexite was named for German chemist G. L. Ulex, who first correctly analyzed the species in 1850. Most specimens are milky and very poor quality, but those stones that are cut as cabochons often display a strong cat's eye effect.