Quick Facts
Formation & Origin
Ulexite forms as an evaporite mineral in arid-region playa lakes and borate deposits. When boron-rich water evaporates in closed desert basins, a sequence of borate minerals precipitates out, with ulexite being one of the most common.
The remarkable 'television stone' property occurs in the fibrous variety. Ulexite can grow as parallel bundles of extremely fine fibers, each acting as a natural optical fiber. When a polished slab is placed on text or an image, internal reflection within each fiber transmits the image from the bottom surface to the top, projecting it onto the surface of the stone. This is the same principle used in modern fiber-optic communication.
The cotton-ball variety grows as round, fibrous aggregates that look exactly like tufts of cotton. These form at the surface of evaporating pools where boron-rich water slowly concentrates.
Identification Guide
The fiber-optic property is the definitive identification test. Place a polished ulexite slab on top of printed text. If the text appears projected onto the surface of the stone, it's ulexite. The cotton-ball variety is identified by its soft, white, fibrous aggregates.
Distinguish from gypsum (higher SG, different fiber structure), selenite (similar optical properties but different crystal system), and colemanite (harder, different crystal habit). Ulexite is soft enough to scratch with a fingernail.
Spotting Fakes
The television stone effect is difficult to fake convincingly. Fiber-optic glass could replicate it but would have a different feel and density. The main issue is quality variation rather than fakes. The best specimens project images clearly and sharply. Lower-quality pieces may produce blurry or incomplete image transfer. Cotton-ball ulexite is generally not faked.
Cultural & Metaphysical Traditions
Presented as cultural traditions, not scientific evidence
Ulexite is associated with vision, clarity, and seeing through illusion in crystal healing traditions. Its natural fiber-optic properties make it a natural symbol for insight and perception. Practitioners use it for meditation focused on gaining clarity on confusing situations and for enhancing creative visualization.
Where It's Found
Major source from borate deposits
Evaporite deposits with borates
Large borate deposits
Andean borate deposits
Price Guide
Good to Know
Scratch test: At hardness 2.5, Ulexite can be scratched with a fingernail. This is a display specimen, not a wearable stone.
Sources: Found in 4 notable locations worldwide, from United States to Argentina.
Heft test: With a specific gravity of 1.95, Ulexite feels lighter than most minerals. This lightness can help identify it.
Related Minerals
Fellow borate mineral from same deposits
Common borate mineral, household name
Similar fibrous habit and optical properties