answer:It’s a dollar coin, I can’t say I know much about it but I found this… “The Mint always had engravers on staff who would come up with new designs. Sometimes the designs were at their own initiative, sometimes they were the result of a specific request. Some of the designs were experimental in nature, others raised artistic issues or had to do with format. For example, in 1849, the United States Mint started striking one-dollar gold pieces for circulation. They had a very small diameter because there wasn’t much gold in them. People complained about the coins being difficult to handle and easy to lose, so the Mint had a couple different options. One of them was to increase the coin’s diameter by putting a hole in the middle, so it still contained a dollar’s worth of gold, but it would be easier to handle. The option they ended up adopting was to make a much thinner coin with a larger diameter, which also had just a dollar’s worth of gold in it. Pattern collectors prefer the gold dollar from 1852 with a hole in the middle.” (source) And here’s an image of the 1852 coin, just search on the page for “J-0140”