According to a report from IFLScience, American scientists claim that Earth’s oceans hold an incredible supply of gold—around 20 million tons. At current market prices, this is valued at over $2 quadrillion, making seawater the planet’s largest “treasure chest.”
Most of this gold comes from land. Rocks are weathered by rain and rivers, and tiny particles of the metal are washed into the seas. Hydrothermal vents on the seafloor, especially in areas where tectonic plates collide, also serve as a source of gold.
Despite these vast reserves, the concentration of gold in seawater is incredibly low. One liter of seawater contains only a few femtomoles, which is comparable to finding a single needle in a stadium full of haystacks. Because of this, extracting the precious metal is not economically viable.
Historically, scientists have attempted to develop methods for mining gold from water, including electrochemical approaches and special “sponges” designed to collect trace amounts of the metal. For example, in 2018, a new material was able to extract less than one gram of gold in just two minutes, but scaling the technology for industrial production is not yet possible.
Experts note that despite the difficulties, the discovery of such reserves expands our understanding of the planet’s natural resources and could inspire new methods for the future extraction and use of precious metals.