Using a metal detector, the couple discovered a gold nugget weighing more than 4kg.

This nugget of gold, called Golden Beauty, weighs more than 4kg, is nearly 19cm long, and is considered one of the rare natural gold nuggets that still exist. It was found in 1979 in Kalgoorlie - the land once famous as the center of the "gold rush" in Western Australia.

The couple John and Frances Aggiss were the lucky ones who discovered the nugget while metal-detecting. The Golden Beauty has since been privately owned in Switzerland and is now up for auction.

The Golden Beauty nugget is an extremely rare find, said Craig Kissick, vice president of the natural and scientific division at Heritage Auctions. “Finding a one-ounce nugget of natural gold is more difficult than finding a five-carat diamond,” he said.

Kissick points out that all the gold ever mined in human history would fill a cube about 70 feet long. Most of it has been melted down to make coins or jewelry. Natural nuggets like Golden Beauty have virtually disappeared.

Large gold nuggets in nature are very rare. Photo: Earth

Golden Beauty is being displayed to collectors and investors before it goes up for auction. Experts say the nugget’s unique shape and natural veins make it one of a kind. Each piece of natural gold also reflects its unique geological structure and formation conditions.

Also in this auction, a smaller gold nugget, weighing about 0.5kg, was donated to charity by an anonymous person.

Since the 1800s, Australia has had many large-scale gold mines, attracting thousands of people to this area with dreams of changing their lives. However, mainly only gold scraps were mined, and lumps weighing up to several kilograms were rare.

Collectors prize natural gold nuggets, each piece of gold reflecting the surrounding geology, offering clues about the conditions in which it formed. The striking shapes and sparkling edges of natural gold nuggets often attract attention.

Several large gold nuggets have been found throughout history. The most notable is the "Welcome Stranger" nugget, found in 1869 in Moliagul, Victoria, Australia. Weighing in at 97.14kg (in refined gold), it is considered the largest alluvial gold nugget ever discovered in the world , although it was melted down shortly afterwards.

Also in Australia, the "Welcome Nugget" gold nugget weighing about 69kg was found in 1858 in Ballarat, marking one of the largest discoveries during the "gold rush" period in Victoria.

In Brazil, the "Pepita Canaã" gold nugget with an initial weight of 60.8 kg was found in 1983 at the Serra Pelada mine, is currently the largest natural gold nugget in existence and is on display at the Central Bank of Brazil Museum.

Another notable find was the 27.2kg "Hand of Faith" nugget, found by metal detector in 1980 in Kingower, Victoria, Australia. It is the largest solid gold nugget ever found by this device and is on display at the Golden Nugget casino in Las Vegas.