Ice jewels in Japan

In the coldest months of the year on the Isle of Hokkaido, in Japan, ice forms the most beautiful diamond jewels. They’re cristal clear and the look just like the most precious diamond.
Pieces of ice shine like diamonds during the day and glow like amber at sunset. Why do form here? Well, these ice chunks spit out by the river accumulate on the beach, tumbled by ocean waves. Here they’re known as “Tokachi river ice“, jewelry ice or jewel ice, and they appear only here, and only during the coldest winter months.
These beautiful ice sculptures form with the water of the river and then are pushed by the sea waves on the beach, a movement that gives them a rounded shape.

They are so clear for two resasons. The first one is because it’s ice made of unsalted water:  this gives them a particular transparency, not possible with salty water. The second one is because this particular ice forms during a long period of time.