Buying a coin and then buying its partner, is a natural progression for most collectors. It the quest for completion that most collectors seek.

So, a Kookaburra Penny collector will more than likely want a Kookaburra Halfpenny.

There are other natural 'pairs' within the Australian rare coin market, such as the Perth Mint Proof 1955 Penny and Perth Mint Proof 1955 Halfpenny. The collector that buys the penny will quite naturally seek out the halfpenny. As both have the same mintage (301), buying both coins poses no difficulties.

Holey Dollar collectors will want a Dump and with two hundred Holey Dollars available to collectors and eight hundred Dumps, acquiring a Dump is also an easy one. There are four Dumps out there for every single Holey Dollar.

Now let's consider the position of the Kookaburra Penny collector that aspires to a Kookaburra Halfpenny.

There are two hundred Kookaburra Pennies available to collectors and it would be fine if there was eight hundred halfpennies. Or to give every penny collector an even chance, two hundred halfpennies.

But, it’s a bad news story for halfpenny buyers because there is a pool of only twelve coins coins available to collectors.

It’s these numbers, two hundred pennies and only twelve halfpennies,  that have made the Kookaburra Square Halfpenny one of Australia’s most elusive and sought-after coin rarities.

When the Kookaburra Square Penny and Halfpenny were created, Australians were recovering from the war and determined to lessen the ties with Great Britain. The mood even filtered through to our coinage!

The Government planned to introduce a square penny and halfpenny with our native bird on the reverse. And the monarch minus his crown on the obverse! Provocative and contentious but uniquely Australian.

Australia entered a modern age post World War I. For many Australians, it was a time for breaking out socially, of questioning and changing old values and behaviour and enjoying the good life. It was a time of great change. People forgot the old and embraced the new in an attempt to leave the hardship and struggles of the war behind them.

New technology was being created, like toasters and cars, things that today we take for granted. The fashion world was exploding, great changes were embraced in styles of dress. Australians were identifying with their own culture, keen to lessen the emotional and cultural ties with Great Britain.

Creating a new, totally Australian coinage was a part of the deal which is why the Government floated the idea of the Kookaburra Penny envisaging a coin that would be unique to Australia.

The Government's plan was to discard the British-styled penny and halfpenny and to create a coin with a typically Australian design featuring the nation's native bird, the kookaburra.

To maximise impact, a new shape was planned with the move from circular to square. And bronze was to be discarded and a new metal taken up, that of cupro-nickel.

Tests began at the Melbourne Mint in 1919 and continued for three years, ending in 1921.

Sadly, in 1921 and after three years of testing, the scheme fell apart. The response to Australia’s square coinage was poor with widespread public resistance to change and people generally rejecting the small size of the coins.

Today there are about two hundred kookaburra pennies held by private collectors. And about twelve kookaburra halfpennies.