Effect: An clear plastic ring box is unwrapped from a small piece of cloth. It is seen to be completely empty. Now by waving your hand over the box you cause a real half dollar to instantly appear inside!
The box and the coin can be examined!
They will find nothing wrong as the secret gimmick is long gone.
You can also present this as a penetration effect where you apparently cause the half dollar to pass through the table top and appear visually inside the box!