Most coins of the world are round, but some feature unconventional shapes and sizes, leading to the creation of distinctive error coins found only in some parts of the world. The Australian 50 cent coin comes on a dodecagonal (12-sided) planchet and has the largest size of the circulating coins in the country. Due to this large size, it is frequently the Royal Australian Mint's denomination of choice for commemorative coins, as it can best showcase the intricate artistry of its skilled engravers. It was this artistic appeal that drew me to the 50 cent coin, making it my primary denomination of interest.

During Melbourne's COVID-19 lockdowns, while browsing Facebook coin forums, I came across the ramstrike 50 cent error coin. Its uniqueness captivated me, such that I would say that it became my first love when I began collecting error coins in 2019. The term 'ramstrike' is used uniquely in Australia. PCGS has classified this error in various ways, including 'finned rim', 'partial collar', 'partial collar strike' and 'mis-fed plan in collar' (see certs 39284866, 38479159, 24023639, 37452358). Whilst all these classifications are accurate, in my opinion, 'mis-fed plan in collar' could have been more clearly defined by PCGS. Many Australian dealers and collectors also term this error as a 'scalloped edge', but I personally disagree with this term as I believe it should only apply to coins with an intentionally scalloped designed, such as Hong Kong's $2 coin and the Cook Islands' $1 coin.

What makes this error so appealing on the 50 cent coin is its 12-sided shape. This is because 12 individual rims can be 'pushed up' during the creation of this error coin. Depending on how much the collar die had caught onto the planchet, some or all the rims can be pushed up into small protruding 'fins'. Over years of collecting, I have observed varying degrees of this error - from coins with only a few short fins to those with taller, more pronounced fins. To the collector market here in Australia, those with the tallest and most evenly formed fins command the highest sales prices. See photo below for a top quality ramstrike 50 cent error viewed from the side.

A crucial observation I have made is that every genuine example of this error I have seen only exhibit fins that point 'upwards' toward the reverse. This indicates that the reverse die must have acted as the hammer die. This error occurs when the reverse die strikes the planchet while the collar die fails to engage properly, creating a partial collar, and forcing metal to flow outward and upward - since there is no room to escape toward the obverse. Therefore, it is easy to tell that a coin must not be a genuine ramstrike error if it is described as having protruding fins on both sides of the coin.

The most common year for this error on the 50 cent coin is 1983, accounting for roughly 80% of the examples appearing in shops, auction houses or Facebook groups. I've also seen a few dated 1982, 1984 and 1988, along with only one or two examples dated 1978 and 1981. Despite this disparity in terms of the scarcity across the dates, I have not noticed a great deal of price differences between the dates. This is likely due to most collectors only seeking just one example of this error for their collection, rather than pursuing a date set. Today, the average uncirculated example sells for $400-$500AUD (~$250-$300USD), making it far more affordable than other sought-after errors such as wrong planchets, multi-strikes and brockages, which usually cost thousands.

While this 50 cent error is not as rare and high-value as compared to some other errors, due to its unique eye appeal and relative affordability, it has become a crowd favourite amongst collectors here in Australia. Most collectors prefer keeping these coins raw, as it allows for better appreciation of the fins' details compared to if the coin was encapsulated. I dabble a bit into the buying and selling of error coins here in Australia, so if you are interested in browsing what I have available for sale, please visit my friend's shop, Melbourne Numismatics Exchange, where I sell some of my coins. You can also reach me directly by email if you wish to contact me about any Australian error coins. I am always happy to chat with like-minded collectors!