With the discovery of gold in western New South Wales in 1851, large quantities of unrefined gold began to be circulated as money affecting the official currency. The Government suggested to the British Colonial Secretary a mint be established in Sydney. After some debate, the British Government gave approval in August 1853. This became the first branch of the Royal Mint outside England and twenty British staff were appointed to establish the Royal Mint Sydney.
Joseph Trickett was appointed Superintendent of the Coining Department, to act as Clerk of Works supervising the construction of the Mint.

After considering several sites in Sydney, in March 1854 Trickett suggested the use of the south wing of Macquarie's General Hospital as the site for the Mint.
The Hospital remains the oldest public building in Australia. Built between 1811 and 1816 and was known as the Rum Hospital. In 1811, Governor Macquarie began planning for a new general hospital in Sydney which was to be his first major public building. The contractors were paid with 45,000 gallons of rum hence the name Rum Hospital. Construction was completed in 1816.

In 1854 the mint was established on the site with the hospital building used to house mint staff as well as providing a residence for the Deputy Mint Master. A coining factory was built at the rear. Both of these structures have exceptional heritage significance and have been associated with major events in New South Wales history.
They are also near many other famous Australian historical buildings including Hyde Park Barracks, the Queen Victoria Building and Parliament House.

Its design is loosely based on ancient AAG Greek architecture with its two tiers of columns made of cedar timber in the style of Doric mouldings. The columns are angled inwards creating an optical illusion imitating the Parthenon in Athens.

A dispensary opened in 1842 replacing the south wing after which the rest of the site was used as a military hospital until 1854.

There were frequent major upgrades during the late 1800s and the early 1900s. However, by 1926, with the Melbourne and Perth Mints having much better technology and being more profitable, the mint was closed.

The Government Insurance Office moved into the building as soon as the Mint closed and other government offices followed, including the Local Government Superannuation Board, the Electrical Contractors and Licensing Board and the Family Endowment Department. Government offices kept arriving and going for another fifty years. Gradually these buildings were being demolished.

It was expected that law courts would be established after the demolitions, however activists successfully led a campaign in 1979 to preserve the Mint buildings as well as Hyde Park Barracks. The then premier of New South Wales, Neville Wran, announced that the Mint would come under control of the Museum of Applied Arts and Sciences. The museum closed down in 1997 and the building's ' ownership was transferred to the Historic Houses Trust (HHT).

History of The Mint.
Cruzi's Coins Website