I bought this coin in the early 1990s from a coin dealer near Berkeley, California. I think it's about 90% gold, but I'm not sure. Of course it's no doubt well known by coin dealers how pure it is, and how much it's worth. I don't actually remember the price I paid, but I'm guessing around $100.
A reader, Kane Imai, has helpfully pointed me to a website which lists the value at several hundred dollars, depending on condition. So I think I did OK on this one.
And much later (2007) coin collector Joshua Holman provided this additional information about it:
The coin you have is an 1891-CC (CC stands for Carson City) $5.00 Coronet head gold piece (known as a half eagle). According to the Jan 2008 Coin Prices magazine, the coin is worth anywhere from $315 to $31,000. More details are here:CoinFacts.The very high prices are for uncirculated examples of the coin, mine is quite worn and therefore going to be near the bottom of the range in value.
Source: Coin Shop in California
Contributor: Theodore Gray
Acquired: 15 April, 2002
Text Updated: 21 December, 2007
Sample Group: Coins