The Straits Settlements coinage left a lasting heritage for Malaya, Malaysia and Singapore. In 1963, when Malaysia was formed, the Straits Settlements currency was still legal tender (although the earlier coins had long since disappeared, due to their high silver content). The Malaya and British Borneo coinage was of exactly the same pattern, and on the formation of Malaysia the same basic coin sizes were used. Singapore followed suit in 1965, introducing its own coinage, but following the Straits Settlements sizes.
Over the years there have been some variations. Quarter and half cent coins disppeared early. The 1 cent coin has evolved from a "copper penny", through a square lozenge with rounded corners, to a small round alloy coin. Dollar coins have been and gone and come back again, but the core 5c, 10c, 20c and 50c denominations have lasted in more or less the same format, but made of cheaper metals, for well over 100 years.
The following description is taken direct from Wikipedia:
The first coins issued for the Straits Settlements in 1845 were ¼, ½ and 1 cent denominations in copper. They were issued by the East India Company and did not bear any indication of where they were to be used. A second issue of the same denominations was produced in 1862 by the government of British India. These bore the inscription "India - Straits".
In 1871, silver coins were issued in the name of the Straits Settlements for 5, 10 and 20 cents, followed by copper ¼, ½ and 1 cent the next year and silver 50 cents in 1886. Silver dollars were first minted in 1903.
A 3 page special issue of the Straits Settlements Government Gazette published in Singapore on 24 Aug. 1904, contained the following proclamation by then Governor, Sir John Anderson. From 31 Aug. 1904, British, Mexican and Hong Kong Dollars would cease to be legal tender and would be replaced by the newly introduced Straits Settlements Dollar.
The purpose of this action was to create a separate exchange value for the new Straits Dollar as compared with the other silver dollars that were circulating in the region, notably the British trade dollar. The idea was that when the exchange value had diverged significantly from that of the other silver dollars, then the autorities would peg it to sterling at that value, hence putting the Straits Settlements unto the gold exchange standard. This pegging occurred when the Straits Dollar reached the value of two shillings and four pence (2s 4d) against sterling.
Within a few years, the value of silver rose rapidly such as to make the silver value of the Straits dollar higher than its gold exchange value. In order to prevent these dollars from being melted down, a new smaller dollar was issued in 1907 with a reduced silver content. A parallel story occurred in the Philippines at the same time. The last ¼ cent coins were issued in 1916. Dollars were last struck for circulation in 1920, with 50 cents production ending in 1921. The remaining coins continued in production until 1935
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