Jun 282012
AOC Stamp & Coin Cover Available From Today

Presented by Australia Post and The Perth Mint, the 2012 Australian Olympic Team Mascot Boxing Kangaroo Stamp & Coin Cover features a $1 coin portraying our most famous sporting symbol and an official 60c commemorative stamp postmarked ‘Westminster WA 6061’ in tribute to the Olympic city.

Please note that our allocation is for customers ordering from within Australia only.

Click here for full details.

Jun 282012

It had been known since 1851 that the gold being mined in Australia was of greater purity than that standard in London, and furthermore that the natural alloy in which it was found included a predominance of silver. This was rather different to the copper alloy that the Royal Mint used to harden the gold it used when producing sovereigns.

This fact was borne out by the Royal Mint’s “Trial of the Pyx” in 1856, which showed that the Sydney sovereigns surveyed included on average 0.02% more gold than the London standard required. Although the percentage of silver in the alloy used for sovereigns at the Sydney Mint was higher than that used in London, the cost of the technology employed in extracting it in 1855 did not make it financially viable to do so.

The fact the amounts of extra gold and silver in each Sydney Mint sovereign was extremely modest did not prevent them from being coins of choice with hoarders around the globe. Anecdotal stories of Asian merchants, French peasants and Chinese traders (among others) preferring Sydney sovereigns to those from London abound in the historical literature.

Francis Boyer Miller – A Pioneer in Gold Refining

Francis Boyer Miller was one of two full-time assayers employed at the Sydney Mint, his brother was a non-resident assayer to the Royal Mint in London, and also Professor of Chemistry at King’s College, London.

Francis Miller’s technique for extracting the silver involved the use of chlorine gas: the “Miller Process” involves blowing a stream of chlorine gas over and through a crucible filled with molten impure gold. Impurities in the gold form chlorides before the gold does and these insoluble salts are removed from the melt by skimming the surface.

This process was so effective at extracting additional gold that the Royal Mint paid a bonus of £2,000, being for the exclusive rights to use his process in Victoria. To put this royalty in context, Miller had an annual retainer of £100 when he joined the Sydney Mint in 1853.

Miller patented his process in London in 1867, and conducted a range of experiments at the Sydney Mint throughout 1868 in order to prove the commercial viability of the process.

Evidence of the gradual introduction of Miller’s process can be seen in the characteristics of many sovereigns struck at the Sydney Mint in 1868.

Mint-state sovereigns struck from the natural Australian alloy prior to the introduction of Miller’s process generally have a bright, straw-yellow patina, often with hints of green.

When compared to sovereigns struck earlier in 1868, the first Australian sovereigns with the precise Royal Mint standard of purity exhibit a distinctly warmer, rose-coloured patina.

It is interesting to note that the Royal Mint correspondence registers from this period yield concerns that the higher proportion of silver was causing the Sydney sovereigns to wear thin in an untimely manner.

It is perhaps ironic that Francis Miller’s research into the chlorine refining process determined that the softness in design being observed in London was not due to wear, but actually by the minting technique – a slight “flow” of metal tended to smooth out Victoria’s portrait.

Although Miller’s research could not support any argument there could have been against the continued use of the designs unique to the sovereigns of the Sydney Mint, as his refining process now meant that there was complete metallurgical uniformity across all sovereigns issued by each of the branches from 1868 onwards, which ultimately led the Secretary of State for the Colonies to conclude that:

“My Lords see no reason why coins struck at the Sydney Mint should not bear the same design as those issued from the Mints in London and at Melbourne ; and they will therefore be willing to submit to Her Majesty an Order in Council, giving effect to the wishes of the Government of New South Wales in this respect.”

The 1868 Type II Sydney Mint sovereign is therefore a true turning point in Australian numismatics – not only are some the last sovereigns struck with the “native Australian alloy”, they are also the first that can unequivocally be said to be struck to the exact same specifications as those issued by the Royal Mint in London.

Andrew Crellin’s numismatic career began at The Perth Mint. Subsequently he spent over a decade in Sydney with two of Australia’s leading numismatic dealers. In that time he wrote two acclaimed books on Australian numismatics, appraised The Perth Mint’s archival collection and was nominated to the position of Secretary of the Australasian Numismatic Dealer’s Association. Back in Perth, his company Sterling and Currency specialises in Australian coins and banknotes, from the Holey Dollar of 1813 through to the modern coin sets.

Jun 272012

The 2012 Australian Kangaroo One Tonne Gold Coin issued by The Perth Mint has been confirmed as the largest coin in the world by Guinness World Records and will be featured in the 2013 Guinness Book of World Records available in October.

Staff involved in the mammoth project, whose skills include designing, refining, assaying, casting, finishing and more, gathered together for this celebratory photo call on receipt of our official record certificate.

Key facts about Australia’s world beating gold coin:
  • The coin is cast from 99.99% pure gold
  • It weighs a whopping 1,012 kilograms
  • It measures 80cm wide by 13cm deep
  • And it’s official Australian legal tender!

The coin portrays a bounding kangaroo by Stuart Devlin, the world-famous coin designer and official jeweller and goldsmith to the Queen. For anyone who’d like to own a smaller version, the same depiction is available on kilo releases from the Mint’s renowned Australian Kangaroo gold bullion coin series.

The gigantic coin is now on permanent display at The Perth Mint where it’s become a major drawcard for visitors in our award winning Gold Exhibition.

How we made the 2012 Australian Kangaroo One Tonne Gold Coin


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Jun 272012

The requirement for a military college was highlighted in 1902 by the first Commander of the Australian Military Forces, Major-General Sir Edward Hutton. Following Field Marshal Viscount Kitchener’s 1910 report on the Defence of Australia, Brigadier William Throsby Bridges was given the task of founding the College.

Bridges chose the site of a former a sheep station in the Australian Capital Territory for the new institution. The property was called Duntroon – the name by which the Royal Military College of Australia is popularly known. At its opening on 27 June 1911, Governor-General Lord Dudley announced that the College had been granted the title ‘Royal’.

Founder of Duntroon: Major-General Sir William Throsby Bridges.

With the outbreak of World War I, Major-General Bridges was given command of the 1st AIF Division. College graduates made up much of his staff despite being unable to complete their four-year training

Among the first ashore at Anzac Cove on 25 April 1915, Bridges lost his life at Gallipoli just a few weeks later.

According to the Australian War Memorial, “Bridges began a routine of visits to the firing line, showing a complete disregard for his own safety. On 15 May a sniper’s bullet severed his femoral artery and he died three days later on board a hospital ship. He became the only Australian killed in the First World War to have his remains returned to Australia; he was buried at Duntroon.”

The day before he died, Bridges was knighted by King George V. In total, 40 of his 117 Australian graduates were killed during the War.

Subsequently, Duntroon graduates have led Australian soldiers in every major military campaign Australia has been involved in. Recognised today as one of the world’s leading military colleges, it proudly upholds a famous tradition of training and developing some of the country’s most accomplished leaders.

Silver proof coin honours Australia’s Royal Military College

Issued in 2011 and still available from The Perth Mint, this special Coin and Badge Set commemorates the centenary of Australia’s Army officer training College. More details.

Jun 262012
How The Perth Mint helped diggers find gold in the 1930s

Three factors can be held responsible for a significant increase in the number of gold prospectors in Western Australia during the 1930s: the Great Depression; the rising price of gold; and the discovery in January 1931 of the largest nugget ever found in the State of WA – the 1,135 ounce ‘Golden Eagle’.

The Golden Eagle gold nugget, discovered in 1931.

The head of The Perth Mint, Deputy Master Hugh Corbet, noted that “at the present, time, owing to the hard times, and the high premium on gold there are very many men out prospecting – more of the city type.”

He prepared an instructive pamphlet entitled ‘Hints to Prospectors’ in conjunction with the Mines Department on behalf of miners who are, he observed, “very energetic and resourceful but in most cases… lack the rudiments of technical training.”

The publication proved popular and was revised and re-issued throughout the decade. According to a contemporary report in the Sunday Times newspaper: “The popularity of these booklets is evidenced by the fact that 6,000 copies have been issued… requests coming from all parts of Western Australia, from the Eastern States and New Zealand, and even Canada and South Africa.”

In this fascinating extract from an original pamphlet recovered from our historical archive, Corbet revealed to hopeful diggers how to recognize many geological indications suggesting the presence of gold in the ground or surrounding rocks.

From the historic booklet ‘Hints to Prospectors’ (Seventh Edition 1935): Prospecting Hints for the New Man (pdf 430kb)

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