Simply place an ordinary drinking glass on the Coin Coaster, face down, to form an enclosed dome over the coaster. Nothing can get in or out. Or can it??
Give the glass a magic tap and -CLINK!- a quarter magically appears inside the glass on the coaster! Wow!
The coin is an ordinary coin. You can even borrow a quarter first from your spectator, then put the quarter into your pocket, then pretend to take it “invisibly” out of your pocket and push it through the glass. As soon as you press on the glass, the quarter will appear inside, on the coaster!
You supply an ordinary glass. You can even pull this coaster out at the dinner table, or at a restaurant, and use one of the regular glasses that is on the table.
How’s THAT for amazing!