IT took Fosterville Gold Mine 11 years to pour one million ounces of gold from its open pit and underground operations near Bendigo, but only two years to pour the next 500,000 ounces.
The operation, owned by Canadian gold miner Kirkland Lake Gold, reached its 1.5 million ounce milestone this week after 13 years of mining.
Kirkland Lake, which is listed on the Toronto and Australian stock exchange, claims to have access to another 1.7 million ounces of gold underground at the operation, and continues to spend millions of dollars exploring for more reserves.
The mine employs about 450 people.
The geographical nature of the orebody requires a specialised process to free the gold from the host rock.
Fosterville is one of only about a handful of operations around the world that uses bacteria in processing, called Biox technology.
The mine has been owned by a number of companies since 2005 when it first started operation in its current form.