Collectible coins encompass a wide range of numismatic items that are sought after for their historical significance, rarity, or unique characteristics. In the context of the United States, coins from different eras, such as the 1861 issues, can hold substantial value among collectors. The name "Clark" may refer to specific varieties or dealers who have contributed to the coin's history. Items designated with alphanumeric codes, like "G 2 1 2," may signify grading or cataloging systems used to assess their condition and market value. Overall, the collectible coin market is driven by factors such as demand, historical context, and individual flavors of interest among collectors.