Unique star-shaped sand only found on Japanese beaches

All Guide news Project news Investment news Market news

Unique star-shaped sand only found on Japanese beaches

Market news

26/08/2024

Star sand is a sight of beauty and a scientific wonder, each grain of sand once containing a tiny single-celled organism.

Star sand is actually the shell of a single-celled organism that has existed for 500 million years. Photo: Mark Thiessen

At first glance, the beaches on Taketomi, Hatoma, and Iriomote islands may seem ordinary. But take a closer look, and you'll see something very special: tiny, millimeter-sized grains of sand shaped like perfect stars. Scientists say star sand is the skeletal remains of a creature, according to National Geographic.

Most sand is made of rocks, minerals, and corals that have been worn down into tiny pieces over the years. But each grain of star sand once contained a tiny single-celled marine organism. According to Kazuhiko Fujita, a professor at the University of the Ryukyus, star sand is the pitted shell of a microscopic organism called a foraminifera. "It looks like a star in a cartoon. It has a round body with five spines like a starfish," he said.

Foraminifera are usually found on the tops and lower slopes of offshore reefs. After they die, they wash ashore, becoming round and spineless. Over time, the foraminifera shells accumulate on the beach, forming the characteristic five-pointed sand. “If you look at a handful of star sand, you’ll see lots of little stars,” says Mark Wilson, an invertebrate paleontologist at the University of Worcester in Ohio. “Each star is a little individual.”

According to Wilson, foraminifera have tiny photosynthetic algae cells called diatoms inside their shells. The diatoms absorb light, producing carbohydrates and oxygen. So the shell is like a colony of foraminifera and all of these cells. The star-shaped bodies of foraminifera have tiny filaments that help guide light to the diatoms, which then make food.

Found on beaches in Okinawa, Japan, and across the western and southern Pacific, this type of sand is rare. In Okinawa, some islands such as Taketomi, Hatoma, and Iriomote are famous for star sand, but it is difficult to find on other islands. Star sand can act as a protective layer on islands, adding material to the island's shoreline.

An Khang (National Geographic)