World's biggest coin worth $70 million

The biggest, heaviest and inherently most valuable gold coin in the world has been unveiled by the Perth Mint.

Weighing 1012kg, it is more than a tonne of 99.99 per cent pure gold worth more than A$53.5 million ($69.7 million)

The giant coin is 80cm wide, 12cm deep, took 18 months to create and features a bounding red kangaroo on one side and the Queen's motif on the other.

It is Australian legal tender and has a denomination of $1 million - well below its gold value.

Perth Mint chief executive Ed Harbuz said the coin was "the pinnacle of ingenuity and innovation".

"To cast and handcraft a coin of this size and weight was an incredible challenge - one which few other mints would even consider," he said.

Mr Harbuz said the coin was a showpiece of the Australian kangaroo gold bullion coin program, and would coincide with the release of a number of smaller gold coins this week.

The weight and purity of each issue is guaranteed by the West Australian government.

- AAP