1. Condition: The condition of a coin is one of the most critical factors in determining its value. Morgan dollars are graded on a scale from 1 (poor) to 70 (perfect). The higher the grade, the more valuable the coin. Uncirculated coins (graded MS-60 or higher) are generally more valuable than circulated coins.
2. Rarity: The mintage of the 1891 Morgan silver dollar was 12,589,500, which is relatively common compared to other Morgan dollar dates. However, certain varieties and errors within this date can make specific coins more valuable.
3. Market Demand: The market demand for Morgan dollars also plays a role in determining their value. These coins have a strong following among collectors, and their value can fluctuate based on current market trends and demand from buyers.
4. Numismatic Value: Some 1891 Morgan silver dollars may have additional numismatic value due to special characteristics or historical significance. For example, coins with specific mint marks or unusual die varieties can be highly sought after by collectors.
Considering these factors, the value of an 1891 US Morgan silver dollar can range from a few dollars for a well-worn circulated coin to several hundred or even thousands of dollars for a high-grade, rare variety. To determine the exact value of an 1891 Morgan dollar, it's recommended to consult a professional numismatist or refer to reputable coin price guides that provide updated market values based on current market conditions.