Ulexite, or TV rock

How to transmit images with ulexite

Can a stone trans­late im­ages like a TV? Ulex­ite can!

Safe­ty pre­cau­tions

Safe ex­per­i­ment.

Reagents and equip­ment

  • ulex­ite;
  • a flash­light;
  • a piece of pa­per with an im­age or writ­ing.

Step-by-step in­struc­tions

Take a pa­per with an im­age (or writ­ing) and put ulex­ite on top. Watch how the im­age is be­ing trans­lat­ed onto the sur­face of the stone. Point the flash­light along the ulex­ite fibers. Watch how the stone pass­es light along its fibers, but not across!

Ulex­ite is a min­er­al with a fi­brous struc­ture. Its chem­i­cal for­mu­la is NaCa[B₅O₆(OH)₆] • 5 H₂O. Ulex­ite isn’t trans­par­ent by it­self, but it can “trans­late im­ages through.” If you were to place a ulex­ite stone on top of a text line, the let­ters would come through and ap­pear on the sur­face of the stone. Light is con­duct­ed by its fibers thanks to in­ner re­flec­tion — so that the im­age is trans­lat­ed onto the oth­er side of the stone. Due to this op­ti­cal phe­nom­e­non, ulex­ite is also called a “TV rock.” A sim­i­lar ef­fect oc­curs in an op­ti­cal fiber. Com­mer­cial­ly, ulex­ite ore is also im­por­tant as a source of boron.