Japanese researchers have successfully made light-emitting diodes, or LEDs, from rare earth metals found on the seabed south of the country.
The presence of mud containing the rare metals was confirmed in waters off the Pacific island of Minami-Torishima 5 years ago. The area is within Japan's exclusive economic zone.
The group, led by the University of Tokyo Professor Yasuhiro Kato, says they extracted the metals yttrium and cerium from the mud to manufacture white LEDs.
Kato says this is the first time that seabed resources such as rare metals have been used in the manufacture of consumer products.
The group aims to make enough LEDs to be used for lighting at the venues of the 2020 Tokyo Olympics and Paralympics.
Kato says he hopes the use of such illumination will show to the world that Japan, which is said to be a resource-poor country, can make use of its marine and other resources.
Rare earth metals are essential in the manufacture of the latest industrial products such as electric vehicles and smart phones. China accounts for most of the world's production of rare earths.