Hisui Coast

Jade forms in the Kotaki river valley over the prefectural border in Niigata, washes down to the sea, and the current carries it west along this shore. The result is four kilometres of gravel beach at Miyazaki and Sakai in Asahi where you can, with patience and some luck, pick up raw jadeite off the ground. People do — this is a recognised and entirely legal thing to spend an afternoon on, and the local visitor centre employs someone who will tell you whether what you found is jade or not.

The identification rules are specific: whitish, angular rather than rounded, sparkling crystal faces, noticeably heavy for its size, and smooth to the touch. The best time is about three days after rough seas, when the swell has turned the beach over and put new stones on it. The beach is a hundred metres wide, which is unusual for a gravel shore in Japan, and the Northern Alps come down to the water at the eastern end.