Condition: The condition of a coin is one of the most critical factors in determining its value. Coins in mint state (MS) condition, meaning they have no notable marks or wear, are worth more than circulated coins. Circulated coins that show signs of wear and tear will be worth less.
Grade: The grade of a coin is a professional assessment of its condition and appearance. Grading services such as the Numismatic Guaranty Corporation (NGC) and the Professional Coin Grading Service (PCGS) assign grades to coins based on various criteria, including surface condition, strike quality, and overall eye appeal. Higher-grade coins are worth more than lower-grade coins.
Mint mark: The mint mark on a coin indicates the mint that produced it. The 1971 silver dollar was produced at the Philadelphia Mint (no mint mark), the Denver Mint (D), and the San Francisco Mint (S). Coins with certain mint marks may be rarer and, therefore, more valuable.
Generally speaking, a 1971 silver dollar in mint state condition with a high grade could be worth hundreds or even thousands of dollars. Circulated coins in lower grades will typically be worth less. For a more accurate estimate of the value of your specific coin, it is recommended to have it professionally graded and appraised by a numismatic expert.