A CGTN Digital report in mid-March on the discovery of a large gold reserve in eastern China's Shandong Province has drawn a lot of attention from our readers.

The story about Shandong discovering nearly 50 tonnes of gold is listed as one of the most read and shared pieces recently posted on our website.

We would like to explain more about gold, especially the deposit in the world's third largest gold-mining cluster – Shandong, where 4,500 of the world's total 63,000 tonnes of unmined gold is located.

Where did gold come from?

Unlike a lot of valuable items like diamonds, it is borderline impossible to create gold artificially – that's why it's so valuable in the first place.

Scientists have found some ways to create gold, but they are in no way cost effective to be put into practice. As a result, almost all the gold we see in the market comes from mining, or from recycling gold that has already been mined.

Where did the natural gold in mines come from then?

The answer is not clear, and many theories have been proposed. One popular theory is that gold came from the collision of two neutron stars, which releases astronomical – literally astronomical – amount of energy that is enough to create gold.

How was gold distributed on Earth?

Not all lands are equal in terms of gold reserves. Your town may have almost no gold at all, while a neighboring village might possess a massive reserve.

More than a hundred theories have been floated to explain the distribution of gold in the last three decades, according to Zhu Yongfeng, professor at the Institute of Geochemistry, Peking University.

"Most of the theories lasted briefly," he told media. "Some of them were proved to be completely wrong."

Gold rushes spread from one place to another in the last few decades, but not many theories are useful in actually finding gold, he said.

One of the few working theories is that gold reserves can often be found near earthquake belts, as volcanic and magmatic activities can concentrate gold in specific areas.

Why is Shandong special?

Eastern China's Shandong Province sits on the route of the world's largest earthquake belts – the circum-Pacific seismic belt, or the "ring of fire" as some call it.

But that's not enough to explain the large gold reserve in the province, especially in the eastern Jiaodong Peninsula, as the belt stretches all the way along the rim of the entire Pacific Ocean.

Jiaodong Peninsula is also characterized by complex geological structures, including faults and folds, which have created favorable conditions for the formation of gold deposits. Over millions of years, the region has undergone intense tectonic activities, which "pushed" deep-seated gold deposits to the surface.

Gold mining in Jiaodong has lasted for more than two millenniums, and the local people have developed good mining techniques during that time.

The Jiaodong area has become the world's third largest gold-mining site, according to local government data released in late 2020. As of 2021, the retained gold mineral resources in Shandong have exceeded 4,500 tonnes.

So, the newly-discovered 50 tonnes of gold reserve is only a bit more than one percent of the province's total potential.

With the development of modern technology, it will not be surprising if more gold is found in Shandong in the future.