A Victorian grandma has struck gold – literally - after finding a half kilo nugget on a dirt track in Western Australia.

Anne Borg, of Maldon near Bendigo, Victoria, found the 586.5g nugget just outside Kalgoorlie on her 81st birthday in 2013, the Herald Sun reports.

Now she is planning to sell the nugget, which has been valued at around $80,000.

As keen prospectors, Mrs Borg and her husband caravanned nearly 3000km across the country to the West Australian goldfields in 2010.

After toiling for almost four years without luck, she hit the jackpot when she found the nugget hidden under a rock off a bush track.

"I saw the gleam of gold and I just looked to the heavens (and said)' thank you, thank you, thank you'," Mrs Borg said.

"I just kept saying, 'I don't believe it' all to myself — because I didn't believe it.

"I have been detecting for about 10 years and it has made up for all the time I have gone detecting and found nothing."

The dirt track near where the nugget was found, Hall Road, has now become a "big highway" as prospectors chase Mrs Borg’s find.

Mrs Borg said she plans to use the money generated by the nugget's sale to pay off her mortgage and update her caravan.

"I love the bush, the animals and the freedom of caravan living and detecting," Mrs Borg said.

Mrs Borg's find comes just two weeks after another Victorian prospector, Mick Brown, found a 2kg gold nugget near Wedderburn in central Victoria.