Looks like sand spurs

Hoshizuna-no-Hama is a beach 🏖️ located on Iriomote Island, Okinawa, Japan, known for its unique sand composed of tiny star-shaped shells ⭐.

These shells, called Baclogypsina sphaerulata, are remains of foraminifera, single-celled organisms that create them while growing in the ocean 🌊. The shells can be white or brown and range in size from 0.1 to 0.5 millimeters in diameter. Visitors are recommended to enjoy the beach and look for star-shaped sand during low tide ⛱️, without taking sand from the protected area to preserve the natural environment