
Hello there! That's a fantastic question, as that particular coin is a favorite among collectors.
Based on the context from Australian coin collecting groups, you're most likely asking about the 1966 Australian round 50 cent piece. This was a unique, one-year-only coin, and its value comes from its high silver content.
Unlike modern coins, the 1966 round 50 cent piece is made of 80% silver. Because of this, its value is not fixed but changes daily with the international market price of silver. Most of these coins are valued for this silver content, often called their "bullion" or "melt" value.
While the exact amount fluctuates, you can generally expect a round 50 cent coin to be worth many times its face value, often falling in the range of $10 to $15 AUD, depending on the day's silver price. Coins that are in pristine, uncirculated condition can sometimes fetch a slightly higher price from collectors, but for most circulated coins, the value is tied directly to the silver they contain. It's definitely a keeper if you find one


