New Zealand twenty-cent coin pegged to the British pound, was changed to a decimal dollar at a rate of two dollars to a pound. Therefore, 20 cents was worth a tenth of a pound. The 20-cent coin replaced the florin coin which had been worth two shillings, or a tenth of a pound. Like the florin, the new 20-cent coin was made of cupronickel, 28.58 mm in diameter, 11.31 grams in weight, and had 100% edge milling. The 20-cent coin retained the presence of a kiwi on the reverse of the florin, albeit in a different design. The original obverses of 20-cent coins depicted
Penny (British pre-decimal coin) 1797, and contained a smaller amount of copper. In 1857 a survey by the Royal Mint found that around one third of all copper coinage was worn or mutilated, often by advertisements. Two years later Thomas Graham, the Master of the Mint, convinced William Ewart Gladstone, then Chancellor of the Exchequer, that so large a part of the copper coinage must be taken out of circulation that it was worth introducing a whole new coinage which would be "much more convenient and agreeable in use". These new coins were minted in bronze, and their specifications were no longer constrained by