Crystal Thought Condenser

A spectator selects a card from an ordinary deck. Performer displays a small, solid, crystal cube which he explains will condense the thought rays of the spectator. The cube is held right under the spectator’s nose so he can look completely through it. The spectator is asked to concentrate on his chosen card and suddenly an image of it appears inside the cube! Then as quickly as it appeared, it disappears! The cube can then be examined.