None at all. The outer layer of manganese brass just gives it that color. The new Presidential dollars are the same.The U.S. has not used any gold coins for circulation since 1933.
It's not a real coin. Its value depends on how much gold, if any, it contains.
Gold-plated, not real gold. That makes it an altered coin with no real value to a collector.
0.48375 troy ounces (in a real gold dollar from the 1850s)
no
These coins are NOT made of real gold. They are very common and are worth only face value unless the have the mintmark S on the side of the coin.
Is the James Madison dollar coin real gold
You need to be more specific on the date of your coin and the country of origin. For example, some $2 coins are real gold, such as the Newfoundland 2 dollar gold coin which is 22K gold. On the other hand, there are many $2 coins that aren't real gold, for example Australia's modern $2 coin looks golden but contains no real gold, neither does Canada's modern $2 coin. If you are unsure about if your $2 coin contains gold, post a new question including the date and the country of origin.
All Sacagawea coins are Brass. The US has not had a circulating gold coin since 1933.
"The Santa Barbara gold coin" is not enough information for us to know exactly what you're asking about.
Such a coin isn't a real coin and has absolutely no collector value. Rather any value comes from the precious metal content (if any) in the coin. I would take it to a jewelry store or a refiner and have them test it and see how much gold is in it (if any) and then sell it for the price of gold because such a "coin" has no collector value at all.
The best test is density, since a fake coin can still have a real gold plating over a base metal interior. Gold is denser than any other commonly available metal (there are denser metals but they are even more expensive than gold, so they would never be used to create counterfeit gold coins). You can measure the weight of the coin on a scale, and the volume can be determined with the use of a graduated cylinder (to measure how much water it displaces) then you can calculate the density, which is simply weight divided by volume. Compare this to the density of gold. If it's pure gold, the coin is real.
It's not a real person.