BLACK STONE
By Richard Robinson

The magician places a small box on his table. Lifting the lid, he removes five polished black stones. Each stone is of a different shape and has a design painted on it of a unique color.

Asking a spectator to step to the table, the magician moves downstage so his back is to the spectator and the table.

He asks the spectator to lift the box bottom and tilt it forward so that everyone can see the box is empty. He then tells the spectator to pick up one of the stones and hold it in his closed right hand. When spectator informs the magician he's done this, the magician tells the spectator to use his left hand to put the remaining stones back in the box.

The magician asks the spectator to imagine that the color of the design on the stone he holds in his hand is becoming brighter and brighter until he can see the light escaping through his fingers.

When the spectator says he has done this, the magician tells the spectator to put the stone he holds into the box and place the lid on the box.

The magician moves towards the spectator, picks up the box, removes the lid, reaches into the box and brings his closed hand out of the box.

He asks the spectator to call out the color of the design on stone he selected. The spectator does so. The magician slowly opens his hand to show he is holding the stone chosen by the spectator.

Black Stone is a variation of a coin trick that is described in various old magic books. The method when used with coins is so dodgy that I doubt anyone has ever performed it, although it is possible that a few hundred years ago when coins were struck from a single metal the principle may have been more reliable. However using small stones and the proper presentation the probability of success is dramatically increased.

The secret of the trick is heat and thermal conductivity. After the stone has been held in the closed hand it will be warmer than the other stones. Reaching into the box the magician locates the warm stone with his finger tips. The manner in which the effect is presented is important in that the magician must introduce some business which keeps the selected stone in the spectator's closed hand as long as possible.

Props

A quantity of small, black polished stones. These stones are available from florist shops and floral and decorative suppliers. The stones in the photographs are all less than 2 inches long by 1-1/2 inches wide by 1/2 to 3/4 inches thick / 50 mm by 38 mm by 12 to 19 mm. This general size allows the spectator to comfortably close his hand around a stone.

A symbol, hieroglyphic or glyph decorates each stone. The design should be identical, but the color must be different. The design can be painted on or, as seen in the photographs, printed and pasted.

The box is made of wood or stiff cardboard or any other material that doesn't quickly conduct heat or cold. The interior of the box can be lined/insulated with a felt if desired. The lid is simply a square that rests on top of the box.

The dimensions of the box side to side and front to back should be greater than the area taken up by the stones when they are in the box. This allows the performer to put his fingers into the box, touch each stone, then slide that stone out of the way until the warm stone is located. The box pictured measures 5 inches / 12.7 cm square and 2 inches / 5.1 cm high with the lid and bottom 6 inches / 15.2 cm square.

Setup

The stones are put in the box with their designs up which should result briefer handling as the stones are removed from the box and put on the table. The loaded box should be kept in location that doesn't exceed the room's temperature. I suppose it is possible to rest the box on an ice pack prior to working the trick.

Routine

The box is introduced, placed on a table. Lid removed. Stones taken out and positioned slightly apart from each other on the center of the table.

The magician steps forward so the table is behind him. A spectator is asked to stand behind the table, look down at the stones, and choose a design color stone.

The spectator is told to pick up that stone and hold it in his hand so no one can see it.

The spectator is told to use his opposite hand to collect up the remaining stones and put them in the box.

The business of the spectator imagining the color he selected glowing brighter and brighter is conducted.

The spectator is told to put the stone into the box and put the lid on the box.

The magician immediately turns, goes behind the table to stand next to the spectator, lifts the box and holds it out so it is obvious neither he nor spectator can easily see into the box, the reaches into the box, sorts through the stones and removes the selected stone.

Test Mode

The stones can be used as an accessory in another effect, giving the performer a chance to locate the heated stone. For instance, the spectator is asked to select a stone and hold it, the magician deals a number of cards face down on the table. The spectator is asked to touch any card with the stone, then drop the stone into the box and turn the card face up. The magician reaches into the box as if taking out a stone at random, touches two other cards with the stone and when the cards are turned face up one matches the suit and the two total the value of the spectator's choice.

Performance Notes

When first working this effect three stones can be used rather than five.

My thanks to Akemi Yoshida who helped me avoid getting lost in translation.

In discussing the heat principle with Meir Yedid he suggested that some types stone may absorb and hold heat better than others. Having once achieved the distinction of the being the first student in two decades to fail a college geology rock identification test, I only mention this as a possibility.