Coin Thru Glass by Vincenzo Di Fatta

The magician shows the audience a small plate, and puts a U.S. Quarter coin on it. He then introduces a solid transparent glass and places it mouth downwards over the coin on the plate. Now with a U.S. Penny coin he starts to tap the bottom of the glass and suddenly, the audience will see and hear the coin penetrate though the bottom of the glass and drop next to the quarter. 

Use your own glass and your own coins.

A wonderful effect!