Can you spare some change? How about a 1 million Canadian dollar coin?

Here in Vienna, the world's largest gold coin is set for auction after its investment firm owner went bankrupt.

The 2007 coin weighs 100 kilos, has a 53 centimeter diameter, and is made of the purest gold - according to the auction house's expert.

[Michael Beckers, Dorotheum Auction Expert]:
"New methods had to be developed to mint 100 kilograms of gold of this purity. This kind of gold is extremely soft, but it has an extremely gold color which can never be reached in jewelry where you can find white gold, red gold and some other colors. This is a peculiarity of this piece and there are only five such coins in the world."

Though the coin's face value is 1 million dollars, it's expected to sell for more than 4 million U.S. dollars.

Other similar coins are owned by Queen Elizabeth and two unidentified owners in the United Arab Emirates.

This heavy chunk of change goes on sale June 25.