The five cent piece will be withdrawn from circulation or die out naturally very soon, according to the Royal Australian Mint and Assistant Minister to the Treasurer Alex Hawke.

The demise of the country's smallest coin will come about due to its increasing irrelevance but despite the economic argument against it - the high cost of production - easing with lower commodity prices.

Confirmation of the impending doom comes as the Royal Australian Mint celebrates 50 years of decimal currency with commemorative coins and a new book, Inside the Vault by Peter Rees.

"We can foresee a time in the near future where [the five cent coin] will be removed from circulation. The inevitable forces on that are at work," Mr Hawke said.

Ross MacDiarmid, chief executive of the Royal Australian Mint, expects it to "die of its own accord" thanks to its uselessness without any need to officially withdraw it from circulation.

"On the basis of current demand for the five cent piece, our forecast is that it's likely to drop off our production requirements in the next five to 10 years," he said. 58.2 million were minted in 2014, compared with 145.3 million a decade earlier.

But the little echidna-clad coin battles on and its downfall has been prematurely mooted in 2009 and again in 2011.

It survived a 2015 review and the cost of producing each one has almost returned to parity with its face value - thanks to plummeting copper and nickel prices - after climbing to seven cents last year.

With the rise of cashless payments, the future of hard cash is uncertain. The Mint has seen a 25 per cent decline in demand for coins over the last three years (but with a slight and mysterious upturn in the last year), according to Mr MacDiarmid.

About 5 billion coins and $1.3 billion banknotes are in circulation and the chief of the Mint surmises that people still appreciate the security, trustworthiness and anonymity of cash and transacting with it.

While consumers and retailers are mostly on board with getting rid of the smallest denomination, many charities appreciate it.

Elliot Costello, chief executive of charity Y-GAP, says they have collected 10.9 million five cent pieces in a campaign created specifically for the coin.

"That's just short of of $600,000 we've proudly taken off the hands of Australians and put towards remarkable initiatives aimed at eliminating poverty," he said in December.

In 1990, the one and two cent coins were abolished when their bullion value exceeded their face value and inflation caused them to lose their purchasing power.

Sunday, February 14, marks five decades since dollars and cents replaced pounds, shillings and pence - an event known as Currency Day or C-Day.

This saw Australia catch up with the 90 per cent of the world already on decimal systems and undergo an unprecedented four-year education campaign, including the well-known jingle to the tune of Click Go The Shears.

Fifteen billion coins later, the Mint has produced commemorative pieces for the anniversary that pay homage to the pre-decimal designs.

Inside the Vault: The history and art of Australian coinage details the surprisingly rich history of money in Australia.

It tells how Australia's longest serving prime minister Robert Menzies wanted the currency to be known as the Royal but a shocking public backlash killed that off. Harold Holt, the treasurer in the lead up to Currency Day, at one stage suggested it be called the Austral.

Two decades later, when the $2 denomination was converted from a note to a coin, then treasurer Paul Keating scuttled a plan to put a wombat on it, insisting that Indigenous people be represented, resulting in the elder we see today. 

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