There are five New Zealand coins currently in circulation − 10c, 20c, 50c, $1, $2.
Designs on New Zealand's coins have not changed significantly since decimal currency was introduced in 1967. These initial coins were intended to match some of the previous imperial currency, for example the 20 cent piece was the same size as a florin.
It was in the late 1980s that the two lowest denomination notes, the $1 and the $2, were ‘coined'. These coins were released in 1990, made of aluminium bronze, and featured a kiwi on the $1 coin and a kotuku on the $2 coin.
A 20 cent piece featuring a Maori ‘pukaki' carving was released in 1990, because the kiwi motif was moved to the $1 coin.
The ‘heads' design featuring the Queen's portrait was updated in 1986 and again in 1999.
In 2015, the Reserve Bank launched a special coloured circulating commemorative coin to mark the spirit of Anzac that was forged 100 years earlier on the shores of Gallipoli.
For more history about New Zealand's coin, see The history of New Zealand's coinage.
New Zealand's plated steel coins
In 2006, new and smaller plated steel coins were introduced to replace the older cupronickel 50, 20 and 10 cent pieces.
New Zealand's plated steel coins are manufactured by the Royal Canadian Mint, in its Winnipeg factory.
Plated steel coins differ from older cupronickel coins which were demonetised in November 2006. During the manufacturing process the steel core is covered with layers of nickel and copper, giving the coin its characteristic colour and surface.
Forgery of coins is fairly uncommon, mainly because the work required to forge a coin is hardly worth the small reward. Nevertheless, all designs on a real coin should be clearly defined, and it should have a distinct ‘ring' when dropped on a table-top, rather than a ‘thud'. The $1 and $2 coins have special security edging.