mineral

Ulexite

NaCaB5O6(OH)6·5H2O

AI-generated identification · may be incorrect

Hardness: 2.5 on Mohs scale. Color: White, colorless, or grey. Luster: Silky to vitreous. Crystal structure: Triclinic, often forming fibrous masses or 'cotton ball' aggregates. Cleavage: Perfect on {010}. Specific gravity: 1.95 to 1.96.

Hardness: 2
Color: White, colorless, or grey
Luster: Silky to vitreous

Identified August 3, 2026More mineral →

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Physical properties

Formation & geological history

Formed as an evaporite mineral in arid regions, particularly in boron-rich playa lakes and salt pans through the evaporation of water over millions of years.

Uses & applications

Used as a major source of boron and borax compounds for the manufacturing of fiberglass, ceramics, and detergents. Also popular among mineral collectors for its unique fiber-optic property.

Geological facts

Ulexite is famously known as 'TV rock' (television rock) because the fibers act as natural fiber optics, projecting an image placed beneath the crystal onto the top surface.

Field identification & locations

Identified by its fibrous appearance, very low specific gravity, and the distinct fiber-optic text-projecting phenomenon. Found in playas of the southwestern United States, Chile, Argentina, and Kazakhstan.