ARC. During the reign of Tupou Taufa, Tonga's coinage underwent significant changes. Early coins were based on the British pound, but in 1961 Tonga introduced decimal currency and new coins were minted in decimal denominations. 1949-1960: Penny: bronze, 1.2 grams, halfpenny: bronze, 0.6 grams, farthing: bronze, 0.3 grams, shilling: silver, 5.67 grams, florin: silver, 11.34 grams.1961-1965: 1 cent: aluminum, 0.6 grams, 2 cents: bronze, 1.2 grams, 5 cents: nickel, 2.5 grams, 10 cents: silver, 3.5 grams, 20 cents: silver, 6.0 grams, 50 cents: silver, 12.0 grams. IV. A number of commemorative coins were minted during Tupou Taufa's reign, including: 1953: Coronation commemorative coin1963: 10th anniversary of Tonga's independence1965: IV. To commemorate the death of Tupou Taufa, early Tongan coins bore the portrait of the British king. After the decimal change, the Tongan coins bore the portrait of the Tongan king. The Tongan coins were minted by the Royal Mint in London.