Ulexite

Ulexite is a rare, borate mineral, known as the "TV rock" or "television stone" due to its unique fiber-optic property: it transmits images from one side to the other, acting like a natural fiber optic cable. This white, silky mineral, often found in fibrous masses or cotton-ball-like clusters, can be cut into cabochons to enhance its "cat's eye" effect (chatoyancy) but is too fragile for most jewelry.

Key Characteristics:
Optical Property: Displays natural fiber optics, projecting images from underneath onto its surface.
Appearance: Typically white, translucent, with a silky luster, formed in fibrous bundles or rounded masses.
Chemical Formula: Sodium calcium borate
Hardness: Very soft (2-2.5 on the Mohs scale), making it brittle.
Formation: Found in arid areas, often associated with borax deposits.

Uses:
Collector's Item: Prized by mineral collectors for its novelty and unique visual effect.
Cabochons: When polished, it can show strong "cat's eye" chatoyancy, but faceting is difficult due to its fibrous nature.
Metaphysical: Marketed for mental clarity and intuition. 
Where it's Found: Major deposits are in Boron, California (USA) and Turke