The Perth Mint unveiled Thursday the world's largest gold coin weighing over a ton and cost $53.5 million to make. It is made from 99.99 percent gold.

The 1,012 kilogram in $1 million denomination measures 80 centimetres wide and 12 centimetres thick. One face is engraved with the Queen's image and the other side with a kangaroo.

A dozen people worked for 18 months to make the coin.

"The largest coin in the world up to now has been 100 kilograms, made by a competitor mint, and we thought well, we'd better make it so much bigger that it'll stay the biggest coin in the world for a long time" said Perth Mint chief executive Ed Harbuz, according to Perth Now.

The unveiling of the coin coincides with the release of a number of smaller gold coins this week.

The previous record holder for the largest gold coin was the 100-kilogram $1,000,000 Maple Leaf coins made by the Royal Canadian Mint.

There were five of such coins and one was auctioned for 3.27 million euros in June last year in Vienna, Austria. Spanish gold trading company ORO won the bid for the coin.

The Austrian firm AvW acquired the coin in 2007 but sold it after becoming insolvent.