It is worth whatever 1 troy ounce of silver is worth. At the moment it is around $32 an ounce. Though it fluctuates. Sites like Kitco are good at having the current spot price which determines the worth of your silver round.
It's a "Silver Round" and the value is for the silver only, about $30.00.
It isn't an error, it is a privately minted round. It isn't legal tender and the actual design gives it no value. What does give it value however, is the 1 troy ounce of silver in it, at the time of writing silver was around $28.69 an ounce, so that is what your silver round is worth. Keep in mind that silver prices are very volatile and increase or decrease daily.
That's not really a $1 coin, but rather a 1 ounce silver bullion round. At current silver prices (as of 28 September 2012), it's worth $34.50.
What you have isn't a US coin, but rather a privately minted silver bullion round. It is worth whatever 1 troy ounce of silver is worth, at the time of writing it is worth about $34, but the price of silver fluctuates, sometimes wildly, so tomorrow it will be worth more or less.
It is worth whatever 1 troy ounce of silver is worth. Today it is worth about $30, although the price of silver fluctuates.
....Its a 1 ounce bullion coin/round. These are privately minted rounds produced as an easy way to invest in silver. They are usually not dated because they are not numismatic products and aren't collected as a coin is. Rather they are just worth their intrinsic silver value. Today they are worth about $30, but it depends on silver spot price.
Using today's (27 July 2012) silver price of $27.70 per ounce, 1/10 of an ounce is then worth $2.77.
The U.S. did not make any dollar coins dated 1816. From your description, it's a silver round not a genuine coin. Value is about $19.00.
$30.91 on 1-1-11
The spot price of silver.
The current price of silver is about $17.75/oz What you have is a bullion piece sold for its silver content. The $1 denomination is artificial.
Current Spot Price is $27.03 per ounce.