The 1938 Buffalo nickel with an F on the front is a rare and valuable coin. The F mint mark indicates that the coin was minted at the Philadelphia Mint, and the 1938 Buffalo nickel is the only coin from that year that was minted in Philadelphia. The coin is also made of 75% copper and 25% nickel, which gives it a distinctive color. The 1938 Buffalo nickel with an F on the front is worth around $100,000 in good condition.