Reference

Over time, the weight of coins can change due to both wear and minting practices. Here's a detailed look at how these factors impact a coin's weight:

Wear and Tear

Coins lose weight over time as they are handled, circulated, and subjected to various environmental factors. Key points include:

1. Erosion from Circulation: Coins experience gradual loss of metal as they are circulated. For example, silver coins in the early 20th century were found to lose about 5% of their weight due to wear (NGC Coin Forum).
2. Minimal Impact on Total Weight: Despite this erosion, the overall weight loss could be relatively minor. Studies suggest that while the weight loss from regular use may not be substantial, it is still perceptible (APMEX).

Mint Practices

Minting practices have evolved, impacting the weight and composition of coins over the centuries:

1. Historical Coin Production: Early mints had varying standards and quality controls. Coins could be more susceptible to weight inconsistencies due to less precise technology (US Mint).
2. Clipping and Recoinage: During the medieval and early modern periods, coin clipping (the practice of shaving off small amounts of precious metal) significantly reduced coin weight, leading to recoinage efforts like the Great Recoinage of 1696 in Britain (Atkinsons Bullion).
3. Modern Minting Standards: Today, minting technologies and standards ensure greater consistency in coin weight. Errors and deviations are typically caught during production, resulting in fewer weight discrepancies (Wikipedia on Mint-made Errors).

Conclusion

Understanding the changes in coin weight also involves recognizing historical and technological advancements in minting practices. Wear and tear from circulation inevitably reduce a coin's weight, although the actual impact might be minor with modern coins. Additionally, minting practices have evolved to mitigate weight inconsistencies and reduce the impact of practices like clipping.

For more detailed insights, refer to sources like the U.S. Mint and APMEX.