Ulexite

Ulexite is a hydrous borate (a boron compound) of sodium and calcium, found as silky white rounded masses or in parallel fibres. Wikipedia explains that its fibres carry light along their length, so a polished piece can show an image of whatever lies beneath it, which is why it is sometimes called TV stone or TV rock. Hall describes a clear, silky, squarish crystal that magnifies, easily obtained. Hall associates ulexite with clarity and objectivity, with understanding dreams and visions, with meditation and relaxation when placed on the third eye, and with imagination and creativity, especially in business. She also says it is used for clearer eyesight and as a skin elixir, and warns that it dissolves if left in water too long.