The oldest color decorative object in Japan, made from a type of tusk shell, is seen at the Okinawa Prefectural Museum and Art Museum in the prefectural capital Naha, on Oct.... It was discovered at the Sakitari-do cave site in the prefecture city of Nanjo.... According to the Okinawa Prefectural Museum and Art Museum, the bead, made of a type of tusk shell and measuring about 13 millimeters long and 8 mm wide, was found coated in red pigment....