General Notes Regarding Classification of Australian Coin Types

Posted by Mark Duff on 3/18/2014

Mark Duff of Strand Coins in Sydney, Australia, provides an overview of the variety attributions for the "Benchmark Collection of Australian Pre-Decimal Coins"

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Since the advent of currency, coins have reflected the progress of a nation, revealing in their designs and composition, the politics and commerce of the society that they support. It was therefore important that a new Australian coinage was recognisable, consistent and trusted.

The need for a new Australian currency arose on January 1, 1901, when the six separate British self-governing colonies of New South Wales, Tasmania, Queensland, Victoria, South Australia and Western Australia came together to form the Commonwealth of Australia. But it was not until 1910 that circulating British currency began to be replaced by the first Australian silver threepences, sixpences, shillings and florins, followed by halfpennies and pennies in 1911 and new Commonwealth bank notes in 1913. Although the bank notes were quickly adopted it took longer for the coins to change over and by the early 1920s up to 30% of circulating coins were still British.

1901-Dated Letter Concerning Australian Coinage signed by Edmund Barton, the first Prime Minister of Australia
Click images to enlarge.

The London branch of the Royal Mint created all the original master tools (hubs and dies) for the Australian Commonwealth coinage and was also responsible for striking most of its coins until 1915. To meet demand it also supplied master tools to the Heaton Mint and the Calcutta Mint, which were contracted to strike coins for some years before its branch mints in Australia took over full production. Even the emergency dies created by the Melbourne Mint in 1919 and later, during World War II, by the Calcutta, San Francisco and Denver Mints had their genesis in master tools originally supplied by the London Mint.

A new coin begins as a plaster model in relief which when transferred by a pantograph to a steel hub shows a positive image of the intended design. From this hub a master die with a negative image is struck and defining detail such as edge denticles is added. From the master die more working hubs and eventually working dies are produced which theoretically should provide a consistent design for the entire mintage. However, if all or part of this process is repeated then more than one master hub or die can result, with the possibility of noticeable design changes. Intentional alterations are often required and relief detail can be removed from a hub and a new master die created, e.g. at least the last digit of the date is manually removed and re-entered on to a master die for a new year's production. The new date or other mint generated changes such as mint marks can be made to a master die or as a one off to a working die so small positional changes to this detail or even omissions can occur.

The Australian mints had changed dates on dies for gold coins, but it was not until the 1924 issues that the Melbourne Mint officially attempted this process on Commonwealth coins when it added a '4' to the dies of all the copper and silver denominations. This was not always a straightforward operation and in some years overdates sometimes resulted when the original figure was not completely removed from the hub and traces of it showed through around the new date on subsequent dies.

The London Mint did not mark its own production when striking coins, but usually added mint marks to the working or master dies provided to its branch mints or private mints which it sub-contracted to complete orders. By 1919, it was anticipated that the branch mints in Australia were now capable of striking its entire coinage, and so the dies provided to Sydney (halfpenny) and Melbourne (penny) bore no identifiable mint marks. Consequently, in 1919, the Melbourne Mint produced Australia's first pennies on un-marked working dies provided by the London Mint, ie the 1919 'Plain' Penny while Sydney struck the halfpennies.

The Melbourne Mint soon exhausted its supply of dies and as an emergency measure decided to use a pair of working dies to produce a master hub and then a master die from which it derived a further supply of working dies. This accounts for the later production of pennies bearing a small dot below the bottom reverse scroll, ie 1919 //. Penny, a mark to distinguish the additional work on the dies claimed by the Melbourne Mint. Melbourne had been striking all the silver coin denominations since 1916 on dies supplied by London with an 'M' mint mark, but the application of a dot to the 1919 Penny reverse die was the first time in the Commonwealth series that the Melbourne Mint had sought to distinguish the production of coins from dies to which it laid some claim. Whether by need or design, it is also apparent that during the process of producing a hub and then a master die from a working die, the Melbourne Mint added its own distinctive flourish to the fine detail on the legends. These altered legends appear on penny dates through the 1920s and 1930s and are noted in the coin types in the Benchmark Catalogue by an 'm' after the original source die, for example 'Bm' (indicating a Birmingham die altered by the Melbourne Mint). From 1919 onwards, there is also some evidence that the Melbourne Mint also worked on the obverse dies, as in some years slight curving of the letters in the legend can be observed. We have chosen not to recognise these small changes to the obverse dies, because unlike the dated reverse dies that quickly became obsolete, obverse dies could be used over a long period making them very difficult to classify.

1919(M) Dot Below Bottom Scroll Penny OBV.1/REV.Bm
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In July 1920 the Melbourne Mint sent three pairs of 1919 dated working dies to the Sydney Mint so it could prepare for the ceremonial striking of its first penny in October of that year. These were experimental dies that were lightly used to test the presses for the 1920 Penny production and the reverses were marked with an additional dot above the top scroll to distinguish their production from the Melbourne minted 1919 //. Penny. Significantly, the obverse dies were the English type which were the only ones held by Melbourne at the time. The 1919 .//. Penny that resulted is a scarce coin with perhaps a mintage of around 25,000 and marks the first 'unofficial' Sydney struck penny. Records show that the 1919 .//. reverse dies were destroyed in 1924.

One of the great conundrums of the Australian Commonwealth series is establishing the number of varieties of the 1920 Penny and determining the mints where they were made. It is recorded that in August 1920, the Melbourne Mint received 20 Indian obverse dies and 20 Calcutta reverses via the Calcutta Mint of which 17 pairs were forwarded on to the Sydney Mint so that it could strike its first pennies. The Melbourne Mint had assigned to Sydney the /./ mint mark to distinguish its production and by far the vast number of coins that were eventually struck on the dies that were provided were the 1920 /./ variety. However, at the ceremonial striking of the first penny in October 1920, the reverse die that was used was certainly a 1920 Plain Penny, e.g. with no mint mark, as it would have been inappropriate to present to dignitaries coins bearing an unauthorized mint mark. The rarity of the 1920 Plain Penny coin in high grade suggests that only one plain reverse die was employed to demonstrate the presses, and it is likely that the better examples that have survived were souvenired by those in attendance at the ceremony, with some retained for institutional collections. As was the usual practice, production from the die would have continued on until it was exhausted, and perhaps another 50,000 coins were struck that made their way into circulation. Paradoxically, this variety has long been considered a common coin in low grade, but on closer inspection almost all examples in average circulated condition are revealed to be the very common 1920 //. Penny struck on a filled die.

In November 1920, the Melbourne Mint sent 12 sets of experimental penny dies to Sydney so that it could gear up for the main production of the 1920 /./ penny. It received three reverse dies struck on 'Calcutta' steel blanks and nine made from 'Melbourne' steel. According to anecdotal reports, the finished reverse dies were marked by Melbourne with a combination of dots to identify both the origin of the steel used in the die production and the mint (Sydney) at which the coins were to be struck, so that in theory it would be possible to distinguish the production from each die combination. Just 146,160 coins were struck on these experimental dies and this figure must have also included the unrecorded production of 1919 .//. pennies. Many believe that this early attempt to single out mint production was quickly abandoned and that it is impossible to determine how many of each variety were struck and where. But if the Melbourne Mint had gone to so much trouble it seems unlikely that the experiment was not pursued, and simple logic seems to offer a credible distribution. The Melbourne Mint claimed the //. mint mark on the 1919 //. Penny and the .//. mark had been assigned to the Sydney Mint when it was provided with the experimental 1919 .//. dies. The protocol having been set, it can be safely assumed that the 1920 .//. Penny is a Sydney strike. In 1919, the production from both the Melbourne and Sydney mints employed English obverse dies which would explain the very small numbers of 1920 //. and 1920 /./ pennies struck experimentally by these mints with this obverse. In November 1921, the Perth Mint requested dies from Melbourne so it too could experiment with penny production. However, it was the Sydney Mint which was able to respond by sending two sets of 1920 dated dies which, on balance, probably had the .// mint mark. It seems logical that the Sydney Mint would follow the Melbourne lead in passing on this mint mark to Perth, so its coins would be readily identifiable. A mint worker at the time is reported as having had vague recollection of a Perth mark, and as the .// was the only assignation not claimed exclusively by either the Melbourne or Sydney mints, the 93,600 coins struck at the Perth Mint were more than likely the 1920 .// Penny.

There is a counter theory that all the 1920 penny varieties, except the 1920 /./ Penny, were struck by the Melbourne Mint. The thinking behind this idea is that examples of the 1920 .// Penny, the 1920 Plain Penny, the 1920 .//. Penny and the 1920 //. Penny were displayed at a numismatic society meeting in Melbourne in November, 1920. However, the likely explanation is that the Melbourne Mint tested the dies for all the reverse varieties that it had manufactured, including those sent to Sydney, and it was from these trials that examples were displayed.

The 1922/1 Overdate Threepence is a controversial coin that appears to be an early experiment by the Melbourne Mint to alter the date on a die. It is thought that in this instance the last figure on a working hub was simply hammered flat and a new figure was roughly re-entered on the ensuing die. The 1925 Shilling is also an overdate, but it is evident that in this case a master hub was created from the unutilized 1923 shilling master die because the entire mintage including the proofs show elements of a 3 under the 5. Although there is no record of its production, the 1933/2 Penny is undoubtedly the product of the Melbourne Mint altering a 1932 dated hub. Why this process was undertaken in 1933 remains a mystery as penny production appeared robust with 6,781,800 coins struck. It seems likely that the overdate is the result of experimentation with just a few reverse dies. A possible explanation was that retiring mint staff were called upon to impart their knowledge of this skill before their departure. The last of the recognised overdates is the 1934/3 Threepence which like the 1925/3 Shilling was derived from an unused master die. Although no 1933 threepences were struck for circulation, a master tool was obviously prepared and later altered to produce the 1934/3 Overdate. It is far more common that the 1922/1 Overdate, probably being the product of more than one working die, but is still only a small part of the overall mintage for 1934. It is estimated that about 50,000 of the 3,404,000 threepences dated 1934 are overdates.

1922/1 Threepence OBV.2/REV.A
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King George V died in January 1936 and Edward VIII ascended the throne. The London Mint prepared obverse tools (hubs and dies) for all denominations featuring the new monarch, but on the abdication of the king these were destroyed. No Australian coins were struck with an Edward VIII obverse. However, the hubs for the penny and threepence had made their way to Australia and their destruction was confirmed by letter on December 19, 1936. Penny size models of the new 1937 kangaroo reverse struck in bronze exist, as do double sided 1937 pattern pennies featuring King George VI. Uniface patterns of the threepence, shilling and florin are known in institutional collections and some have made their way into the hands of collectors as did a double-sided 1937 Threepence of George VI. The later coin has always been the subject of doubt as it was thought, that except for the penny, no double-sided patterns were struck, but it has recently been reported that the Royal Australian Mint holds double-sided examples of the threepence, shilling and florin in its collection as well as a master die of the 1937 Penny reverse. No 1937 halfpenny or sixpence reverse patterns are thought to exist and coincidentally when the first circulating coins of George VI were introduced in February, 1938 these denominations kept the old reverses.

The 1939 Halfpenny started out with the long standing Type A - 'COMMONWEALTH OF AUSTRALIA' - reverse that began in 1911, but at some point during production a new design was introduced featuring a scaled down and inverted version of the new kangaroo penny reverse. Two distinct reverse dies were used for the production of the new 1939 ‘Roo’ Reverse Halfpenny and these reverse types, with observable differences, alternated on halfpennies produced in later years. The new London master die for the ‘Roo’ reverse can only have been used experimentally as very few 1939 ‘Roo’ halfpennies of this type have surfaced. This new Type B reverse is characterised by very detailed fur lines on the paws of the kangaroo and on the underside of the tail, and a series of prominent rib lines found at the juncture of the leg and torso. However, these features may only be visible on early strikes, so the easiest way to distinguish this type is to examine the foot of the 'Y' of 'HALFPENNY' which exhibits a double foot. The Type Bm reverse is by far the more common type found on the 1939 'Roo' Halfpenny. In comparison to the Type B reverse it is generally less detailed and is readily identified by the foot of the 'Y' of 'HALFPENNY' which is truncated on the righthand side and is best described as having a single foot. These changes were likely initiated by the Melbourne Mint which had a history of altering dies when producing a new master, and the truncated foot on the 'Y' of 'HALFPENNY' is likely a marker to claim its additional work. As a testament to its skills, it struck 100 proof halfpennies with the Type Bm reverse which were offered for sale to the public. Only a single example of 1939 'Roo' Proof Halfpenny with the rarer Type B reverse has been observed to date.

By 1940, World War II was causing severe shortages and the Perth Mint received a request by the Australian Treasury to help out the overstretched Melbourne Mint by producing £8,000 of pennies and £4,000 of halfpennies. Penny production was immediately ramped up and the Perth Mint struck 1,113,600 pennies in 1940 marked with a surreptitious ‘K.G’ mint mark that distinguished its coins from Melbourne’s. The first Perth halfpennies struck in 1942 were for the first time identified by the addition of a dot after 'HALFPENNY' while the Bombay issues are readily identified by the I mint mark on the obverse below the head of George VI and dots before and after 'HALFPENNY' on the reverse. It is not certain whether the Melbourne Mint supplied the Bombay Mint with dies for this emergency war issue, but if so it would appear that the reverse dies were not used directly.

A model was produced by the Bombay Mint from either a struck coin or a die of the unaltered London 1939 'Roo' reverse from which it derived working dies to produce the initial coinage. As a consequence, the first 1942 I halfpennies retain the original denticle count and the double footed 'Y' of the unaltered London reverse 1939 'Roo' Halfpenny upon which it was based. Much of the original design remains, so in the Benchmark Collection this die is classified as a sub-Type Bb in recognition of its London origins, but also taking into account the considerable changes undertaken by the Bombay Mint. On this die the kangaroo is leaner and a re-worked eye is both raised and lidded.

The later production of 1942 I halfpennies and all of the 1943 I halfpennies were struck on dies derived from the altered Melbourne Bm reverse but with further changes undertaken by the Bombay Mint. This die is characterised by a single foot on the 'Y' of 'HALFPENNY' typical of the Bm reverse but now with considerably fewer but larger denticles. Because of its further removal from the original design a new Type C has been recognised.

1939 Kangaroo Reverse Halfpenny: OBV.3/REV.B (left) and OBV.3/REV.Bm (right)
Click images to enlarge.

Similarly, the denticle count on the 1942 I and both versions of the 1943 I pennies is fewer than the Australian minted coins of the preceding years, and like the halfpennies the kangaroo is leaner and the eye is raised. Because of the extensive reworking of the original London design, a new Type E reverse has been recognised on the Calcutta pennies.

The 1943 I Penny pennies were struck with both large and small denticles and the latter has been classified as a sub-Type Eb. The denticle count on the small denticle variety remains the same, and in all other respects, it appears to be the same design as the large denticle variety which had continued on from the 1942 coinage. The shortening of the denticles on the later coins may well be explained by the commissioning of a new die off the model with a slightly larger central design. Effectively this would lead to the edge denticles being pushed out and shortened.

1942 I Halfpenny: OBV.3/REV.Bb (left) and OBV.3/REV.C Long Denticle (right)
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Bronze, a traditional mixture of copper, tin and zinc, was the alloy used for the halfpenny and penny denominations. Although the Coinage Act of 1909 specified that the silver coins should be sterling silver, i.e. 92.5% silver and 7.5% copper, there was no specified formula for bronze. There are anecdotal reports that up until the early 1940s the alloy used contained up to 3% tin but then due to the scarcity of this metal during the war years, the alloy was adjusted to 97% copper, 2.5% zinc and 0.5% tin. This change in alloy would account for the slightly brassy look of the later mint state halfpennies and pennies. For consistency we have used the later composition in our coin specifications as although there is an observable difference between early and late date Australian bronze coins there is no certainty when and if this change occurred.

During WWII, the Australian government was also forced to call on the San Francisco and Denver mints to strike coins to overcome a shortage of circulating currency caused by the large number of American servicemen stationed in Australia. In a similar vein, the coins of the Philippines were also struck during WWII by the Philadelphia, Denver and San Francisco mints to allay shortages caused by the large influx of US servicemen. There is no record of master or working dies being sent from Australia to the United States and therefore the coins produced must have been the product of dies manufactured by the American mints. It is likely that a pantograph was used to produce coin models and eventually dies from samples of circulating Australian coins in a process similar to that which occurred at the Bombay Mint. The coins are identified by an 'S' mint mark for San Francisco and a 'D' mint mark for Denver. Mint marks have long been used by collectors to separate coins struck at different mints but the Benchmark Collection also separates the different fonts used on those marks, e.g. the plain and serifed punches used by the San Francisco and Denver mints.

The silver coins of 1946 were the first struck in quaternary silver, a yellowish-white alloy of 50% silver, 40% copper, 5% nickel and 5% zinc. Australia debased its currency partly to repay the United States for more than $12 million of silver that was used during the war years to strike its coins at the San Francisco and Denver Mints. In 1956, $6 million of silver retrieved from withdrawn sterling coins was sent to the United States as part payment of this debt.

Sometimes small observable changes occur within mintages of coins of a particular year. For example, we have distinguished a small number of 1926 sixpences exhibiting an intentional serifed 2 in the date, which also appears on the proofs of that year. The sub-Type Am indicates that the original London die was altered by the Melbourne Mint.

A small change also occurs on the 1946 Florin. These coins may have small and large voids in the 6 of the date. There is some conjecture that coins with a large void in the 6 were the result of the stop-gap use of an inverted 9 punch on the date. The voids on the 6 and 9 of this variety are relatively the same size whereas on coins with a small void in the 6 there is a marked difference with the larger void in the 9. But as proofs of both types are known in the Museum of Victoria Collection the alternative 6 in the date must have been deliberately employed. The mintage of the two types can be traced back to the use of these two distinct master dies and therefore, for consistency, a sub-Type Bm(a) is recognized.

The reverse of the 1953 Florin has large and small denticle varieties, seemingly the result of two slightly different master dies. There are a number of small differences that are evident, but the most noticeable is a double line that runs from the juncture of the tail of the kangaroo to the leg on the large denticle variety. Because of the observable differences to the central design and the denticles this is classified in the Benchmark Collection as a sub-Type Bm(b).

In our coin types, we have chosen to ignore small changes in the positioning of the date or the mint mark but to include major positional shift(s) such as occurs on the 1931 pennies with the mis-aligned 1. We have also separated the wide date varieties on the 1955 Perth pennies, as not only is the difference quite noticeable even to the naked eye it is also apparent that two sets of master dies were working in tandem that year. The most common coin combines an obverse Type 8 with a reverse with a closed 55 in the date. A scarcer coin has the Type 8 obverse with the wide 5 5 in the date while a much rarer variety combines a new Type 9 obverse with a reverse with the wide 5 5. The Type 9 obverse with the closed 55 occurs only on the 301 proofs struck for public sale and is not known as a circulating coin.

Major mistakes such as the omission of a mint mark which occurred on a small number of 1942 I pennies is also acknowledged, as are the changes in the denticle count which is useful in identifying the source of the original master die and is easily determined by aligning uprights in the coin legend with the edge detail (denticles). Except for the Bombay-minted pennies of 1942 and 1943, all kangaroo reverse pennies have 81 thin and 81 thick edge denticles in which the alignment to the legend remained constant until the London struck 1951 PL Penny. This was the first time since 1915 that the Royal Mint had been called upon to strike Australian pennies and halfpennies, and in the case of the halfpenny it relied on a master related to the original 1939 ‘Roo’ die it had sent to Melbourne. With the penny however, it produced a new master hub for the reverse from a 1937 master die but, in adding the edge detail, the alignment of the legend was altered. Although the number of denticles remained the same on this reverse, we have classified it as a new Type F because it signals the point at which the Melbourne and Perth branch mints diverged from the lead offered by the London Mint. On later master dies, the Melbourne and Perth mints added the edge denticles with slightly different orientations, effectively creating a number of sub-types.

By 1952, the Perth Mint had acquired the skill to produce its own working dies from a master die. The mint received two distinct 1951 penny reverse master tools directly from London. These formed the basis of its 1952 master dies. As an interim measure, Perth received a 1951 D reverse master die with edge detail which proved the source of the early 1952 die varieties. It also received a hub of the new F reverse which it altered to produce dies for the bulk of the 1952 pennies it produced. The Perth Mint used the same reverse master die on its 1953 and 1955 pennies before altering the edge alignment on a new master that it used from 1956 onwards. Although it continued to use the D reverse on its pennies struck in 1952 and 1953, the Melbourne Mint did experiment with the new F reverse in 1953 producing a small number of pennies sans serif i.e. missing its traditional serif on the first 5 of the date. It eventually took up the F reverse from 1955 onwards which is apparent from the abandonment of the serif on the first 5.

The timeline of Australia’s pre-decimal coins from 1911 to 1964 provides a valuable insight into its history, and a number of pivotal events were depicted on its designs. In 1927, the opening of Australia’s first Parliament House was commemorated on a florin, as was the centenary of the founding of Melbourne on the 1934-5 Florin. In 1937 a crown was struck for the coronation of George VI but the purpose of that coin was defeated by the release of a 1938 coin of the same design. The Golden Jubilee of Australia’s Federation was also celebrated by a special florin, and in 1954, the Royal Visit Florin marked the first time a reigning monarch had toured Australia. The Benchmark Collection has exceptional examples of these coins.

The last pre-decimal coins were struck in 1964 before Australia transitioned to decimal currency on the February 14, 1966, thus bringing to an end a system of currency that it had inherited from Great Britain. Perhaps as a salute to the past, the Royal Mint in London helped strike the first decimal coins, and the Royal Australian Mint in Canberra, which had replaced Melbourne as the senior issuing authority, called on the Melbourne and Perth Mints to help strike the new one and two cent coins. The Benchmark Collection of Australian Pre-Decimal coin contains all the intentional mint generated varieties that have been identified. Other varieties which are the result of worn dies such as die cracks, design loss or field flaws are not included in the collection.

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m - A master tool (hub or die) altered by the Melbourne Mint.
b - A master tool (hub or die) altered by the Bombay Mint.
p - A master tool (hub or die) altered by the Perth Mint.
(a),(b) - Altered dies with modifications for a particular year.


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