The only thing authentic about it is the original $2 bill it was made from. It's an overpriced novelty item made by taking a normal $2 bill and layering a thin amount of gold on top of parts of the design.
I've seen them and they look impressive but from a collector's viewpoint they're still altered goods and don't have any value to banknote collectors.
Not gold and not plated. It's made of manganese brass. (And yes, it's worth something: it's worth one dollar.)
A 2004 nickel is worth 5 cents. A gold-plated '04 nickel is worth whatever someone is willing to pay for it. There is no standard market value for modified coins like that.
The plating adds nothing to the value of the coin, but if you find someone that wants it, sell it.
Gold plated, but not gold. A private company took an ordinary 1968 half dollar and plated it for use in jewelry or as a so-called "collectible". The underlying coin is made of 40% silver so you could sell it for $2.50 or so, but that's about all. No circulating coins have been made of gold since 1933.
Most 1994 pennies in circulated condition are only worth their face value of $0.01. These coins can only sell for a premium in uncirculated condition. The 1994 penny with no mint mark and the 1994 D penny are each worth around $0.30 in uncirculated condition with an MS 65 grade.
Thomas Jefferson is not currently, nor has he ever been, on the U.S. quarter. What you probably have is the Jefferson presidential dollar from 2007. It's worth one dollar.
$89.00 American Mint.
If it's a Sacajawea dollar, it's not gold and not even gold-plated. Remember, gold is too expensive to be used in modern circulating coins - all "golden" dollars are made of brass. In addition, about a billion Sac's were minted in 2000. That means any uncirculated one will only sell for maybe $2, but a dealer will almost certainly only offer you face value because s/he probably has boxes full of them.
One hundred dollars
Sacajawea dollars aren't gold and they aren't plated. They're made of a metal called manganese brass, and the outer layers are mechanically bonded to a copper core. About a billion Sacajawea dollars were made in 2000 so unless your coin is either a proof or uncirculated one, it's still only worth $1.
If the dates are 1776-1976 your coin is not gold, it's gold-plated. Millions were struck in copper-nickel to honor the U.S. Bicentennial. They're only worth face value to $1.15, except for uncirculated or proof versions. The fact that your coin is plated makes it an altered coin with no extra value, unfortunately.
No. They are made of copper plated with nickel. They are not valuable unless they have the mintmark "S" or are uncirculated. If your coin is gold it is only gold plated and adds no extra value.
Any plated coins are only worth their melt value. Fortunately, as of early 2010 that comes to about $14 retail, or about $10 wholesale, for a 1921 Morgan dollar.
It's not gold plated the Brass in the coin gives it that color and it's not worth more than a dollar
Not gold and not plated. It's made of manganese brass. (And yes, it's worth something: it's worth one dollar.)
If your coin has been gold plated, it has lost its collector value and would now be considered a novelty item -- value about $10 1900-O and 1901-O are not rare dates for Morgan Dollars. In circulated condition, they're worth about $12 each. Nice uncirculated ones are worth about $35 each.
If you are asking about the "golden" dollar with the duck-like loon on one side and the Queen's head on the other, this is actually aureate-bronze plated nickel, and has no gold content. In pristine uncirculated condition, it's worth about $3 on the collector's market; otherwise, it's spending money on your next trip to Canada. :-)