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The Green mountains of Ulexite

This translucent mineral, when placed in direct sunlight, produces an arcing halo of light. The mountainous features are a result of its fracture planes. This mineral is sometimes called TV stone.

Ulexite, also known as "TV Rock," is a fibrous borate mineral that acts like a natural fiber optic cable, transmitting images from its bottom surface to its top through total internal reflection, making it useful for educational displays and novelty items. Found in arid regions like California and Nevada, it's a white or colorless sodium calcium borate (NaCaB5O6(OH)6·5H2O) that's also used as a slow-release source of boron in agriculture. Its unique fiber optic property comes from parallel fibers that conduct light, creating an inverted image on the polished surface.

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Uploaded on January 6, 2026
Taken on January 2, 2026