This unique "star sand" is called star sand! The maker of star sand is Baculogypsina sphaerulata, a marine single-celled protozoa. The so-called star sand is actually the calcium carbonate shell of this protozoa. This protozoan can grow to about 1 millimeter and is one of the few single-celled organisms visible to the naked eye. After they die, the shells washed up on the coast are almost 1 millimeter in size, so they can be seen with the naked eye.
This protozoan originated during the Cambrian period more than 500 million years ago, and has been depositing sand on beaches ever since.
However, most star sand is not that old, because this protozoa still exists today and continues to produce star sand.
In addition, this protozoa is ubiquitous in oceans around the world, so their shells may be found on most beaches, especially tropical and subtropical beaches.
However, in most areas, their numbers are very rare, except for the coral reefs near Okinawa, where they have an amazing population, so star sand is abundant there.
