If you mean a 1966 American quarter, then none.
No it's not. The coin has no silver, 1964 was the last year for a US silver quarter.
25 cents.
A quarter from 2006 would still be worth 25 cents.
25 cents.
No U.S. coins dated 1966 have a mint mark. The '66 quarter is worth 25 cents.
It is worth 25 cents, or one quarter of one dollar. 1966 is not old enough for the coin to have gotten valuable.
yes it is and it is worth $2.70 as of 10/2008
$0.25
It's worth exactly 25 cents.
In circulated condition, it has no added value. A nice uncirculated one is worth a dollar or two.
1966 Canadian quarter is 80% silver and approximately has .1501 Troy oz of silver. So it depends what silver spot is. With silver at $48/oz it's worth $7.20