help with new coin effect

[Boomer Scripps]

so I had an idea for a coin through glass effect, but am a little stuck on how it would be done, the trick goes as follows: the magician borrows a clear drinking glass and turns it upside down onto the table, he then asks the spectaters if he/she could borrow a coin (or ring preferably) and shows that the glass is solid, he then places the coin on top of the glass, waves his hand over it, and in mi-wave the coin is seen falling and clinking around inside the glass.
I have had two ideas on how this could be done, but they're not the best 1) A second coin is stuck to the bottom and the glass refracts the light so that the coin is invisible 2) A sort of sling-shot mechanism to pull the coin around the glass and inside.
help is appreciated.
~Boomer

 

[JButterfield]

Just off the top of my head...

A Raven, a PK ring and a magnetic duplicate coin might work.

Load the magnetic coin into the glass, suspend it with the PK ring and keep it concealed with your hand, holding the glass near the middle. Place a coin on top of the glass, vanish it with the raven, and release the coin suspended by the ring.

John Carney has a three phase routine called the Soft Glass where a coin penetrates a glass. Maybe look into that and see if you can get some inspiration.

 

[Boomer Scripps]

another similar to the one above is kind like a reverse 'ctg' by Alex Ward, the coin is held behind the glass, but when dropped it lands inside the glass, note the coin is not being thrown over the edge, it is simply dropped and then clincks around on the inside.
oh, and could you give me the link to John Carney's 'soft glass', I can't find it

 

[christian1894]

another similar to the one above is kind like a reverse 'ctg' by Alex Ward, the coin is held behind the glass, but when dropped it lands inside the glass, note the coin is not being thrown over the edge, it is simply dropped and then clincks around on the inside.
oh, and could you give me the link to John Carney's 'soft glass', I can't find it

I think it appears in Carneycopia.