1. Rarity: The 1878 Double Eagle is a relatively rare date in the series. It had a mintage of only 2,170,500 pieces, which is lower compared to other years. This scarcity increases its numismatic value.
2. Gold Content: The 1878 Double Eagle is composed of 90% gold and 10% copper, just like other US gold coins minted from 1848 to 1933. It contains 0.9675 troy ounces of pure gold. The current gold spot price plays a significant role in determining the value of the coin.
3. Condition: The condition of the coin greatly affects its worth. Factors such as wear, scratches, and luster determine the grade assigned by professional coin grading services like the Numismatic Guaranty Corporation (NGC) and the Professional Coin Grading Service (PCGS). Coins in higher grades, such as MS (Mint State) or PR (Proof), command higher premiums.
4. Numismatic Value: The 1878 Double Eagle has a rich historical and numismatic value. Collectors often seek out specific dates and varieties, which can further enhance its worth. If the coin has any unique characteristics or errors, its value may be even higher.
Based on these factors, the value of an 1878 gold US $20 Double Eagle can vary significantly. Depending on its condition and rarity, it could range from a few thousand dollars to tens of thousands of dollars. It's always recommended to consult with reputable coin dealers or experts to get an accurate appraisal of the coin's worth.